Sym Jet Basix / Eurox Problems

Discussion in 'Newbie Scooter Tuning' started by Tamiyacowboy, Sep 12, 2016.

  1. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    Piaggio Skipper
    hello somewhat new to forum and have a scooter problem. i own a sym jet basix/eurox 2006 two stroke model. its been derestricted, fitted with a leo vince TT exhaust, stock clutch , naraku belt and runs 3x6 + 3x8 gram rollers in variator. top speed is around 47mph (74.6kmh).

    the scooter did have 6g rollers in until my clutch blew out so i had shop replace the belt clutch and rollers, but bike was very very slow, what they did not do was weigh old rollers it originaly had 6x6g rollers fitted but would peak at max revs and stop pulling at around 42mph, from 30mph to 40mph it would fly along, now it takes a tiny fraction longer but i have gained around 5mph just changing roller weights to staggered 8g and 6g.

    Now here is the problems , seals are all good and crank has no play at all, its had a full top end rebuild in the start of this year, carb is the stock carb with stock intake.
    at full wot after around half a mile the bike will suddenly loose all power, the speed will drop off to around 20mph and hold there, if you shut down throttle and then gas it again the bike starts to die out.
    if you pull over and wait around 5-10 seconds then pull off again the bikes power is back, but again not long after getting to WOT you will get the same symptoms lack of power , dragging down on speed. its feels like the carb bowl is emptying faster than it can be refilled. below 40mph (30mph) you can ride forever and will get no dragging down or lack/loss of power, remember this is a brand new top end and piston and has been run in , but having to try and stop on a busy road due to the power just dropping out is becoming rather dangerous, there is no lean/rich warning to when it will happen it just goes and your somewhat stuck trying to pulling over and waiting a few seconds. if you ride at 40mph constant the power starts to fade away throttle response seems to fade out to like above at wot but its more a gentle fade out

    Next problem, the variator case is getting so hot you cannot put hand onto it, its becoming so hot you can feel the heat radiating from it on your face and touching it for to long results in you wanting an ice bath for your hand, i do know the sym jet had some problems with seals going, but mine are fine ( no gunk - junk behind variator when rollers replaced ), i replaced the gearbox oil to it was very very black so had not been changed at all since the bike left the dealership in 2006. but still i have this very very hot side casing problem, and i am worried its going to start eating my belt or blowing out my clutch/variator and/or bottom end at some point.

    My shop mechanic says it needs a de-coke, but i keep telling them it has a new piston and barrel fitted in jan this year and the 95 quid labour charge for just two hours is somewhat a sting to me. i use my bike for general errands and to get me to doctors appointments and cardiac appointments at the hospital so it is somewhat my life line to freedom and not having to sponge a lift from my parents or ride public transport.

    Any help or ideas would be very helpful so i do not end up with huge repair bills ( bike cost me £220 and already has £250 worth of repairs and labour costs)
     
  2. Stevep

    Stevep Well-Known Member

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    5,895
    Is there a fuel filter in the line at all? Might be just not filling quick enough for the engine requirements.
    As for the case getting hot, is the fan fitted on the variator? And are there any hoses not attached to help cool the inside of the belt case?
     
  3. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    Piaggio Skipper

    yes Stevep i have a fuel filter before the vacuum fuel pump ( sym jets have a tank in the scooters floor so requires a vac line to power it), i am hopeful when it goes back to mechanic monday i can order in a new vacuum pump and whole new set of fuel/vac lines.

    No thats the weird thing about this T5C motor, its an enclosed variator case rubber gasket around the engine housing then a fully sealed variator side case fitted, when the side case was off in the mechanics hands for roller tune i never saw a fan blade fitted to the face plate, it was just a toothed face plate and nothing else, just the drive face and a funny like washer for the kickstart bush to seat into and turn the crank over for starting, ( very basic looking faceplate to no fancy vanes etc etc )

    one thing i have noticed is any upgrade parts must be chosen via its frame number ie BL05W , so its a pain trying to find bore kits / upgrade variators / upgrade clutches, but more so bore kits all i have found have the carb intake fitted to the cylinder , where my model changed and has the intake on the engine case itself.
     
  4. Stevep

    Stevep Well-Known Member

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    5,895
    Most fuel filters are between the tap outlet and carb.
     
  5. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    Piaggio Skipper
    guess sym are a bit backwards, the service manual even show me to fit it before the vac fuel pump lol.
    nice thing is sym fitted the filter in a lovely black color lol, cannot even see if its gunked up, so i have been out and grabbed a universal clear inline filter.

    Hopeful that i can remove the fuel pump without having to tear off the whole body panel set ( sides- lowers - center - floor pan) , i have noticed today in better light is a pug plastic vac pump not the metal ones they were shipped with, but am unable to find a pug vac pump rebuild kit , also noticed a weird thing this evening a lowered drain cover i hit kinda hard ( like a 20ft deep pot hole feeling ) a few seconds later motor started to die away, i think some gunk has somehow gotten past filtering system and into the carb bowl and its blocking either main jet every now and then , no problems with idle or warm up , but the bump gave me an exact replication of my WOT fueling problem.

    thanks for the advice stevep hopefully get little Pedro back to being a two stroke and not a half a stroke put and gurgle
     
  6. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    Piaggio Skipper
    So i have sourced a clear fuel filter to replace the old solid black filter thats been in bike since 2006.
    sourced a 101 octane vacuum fuel pump from a german company, should be on uk soil in start of october.
    my shop boss is back from holidays and no mention of a de-coke, he has the exact though as me a wonkey fuel pump or blocked vac/fuel lines for hearing what happens when the bike starts to play up.

    hopeful i can get this scoot fixed before 28th october for our next bike meet in norfolk , i have had to pass up on the Norfolk 300 ride as little pedro just will not make 100 miles let alone the 150 mile i wanted to ride. Not going to replace these parts myself going to have the shop do it and at same time replace the whole vacuum line and fuel lines , also maybe flush my carb out with some cleaner to. they may know an easy way to get to the areas needed than de-camping the whole body panel set and floor pan
     
  7. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    7,321
    been thinking about this, sounds like its leaning off at WOT and getting a bit hot. it might be worth running just 1 jet size up. should help a little with it.
    and what oil are you using?
     
  8. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    Piaggio Skipper
    in the middle of old school replacing bit that i think could be the cause. have tried 8 companys with dyno roads and NONE will touch my bike or even let it run on dyno , even been told they only dyno fourstrokes ( thats a lie as they are race tuners and you dyno two stroke racers lol )

    rollers - belt - full clutch and rear pully replaced
    rear gearbox drained and 80-95w oil added ( stuff that came out was black as boot polish so never been changed in the 10yrs running)
    Now replacing filter and swapping out the fuel pump for a mikuni copy pump.

    oil brands, i swapped from using putoline 2t fully synth mixing oil to yamalube semi synth 2t. problem was showing even with the putoline mix.
    i run a 5 tank swap, 3 tanks of standard 95ron bp unleaded, 2 tanks of bp ultimate unleaded 97ron. can tell a difference when im running 97ron, bikes a lot more peppy with a better pull, i expect its the added octane and better burn quality with the added detergents etc etc.

    Bikes in on tuesday for the pump swap and filter chop , so i will also throw in a brand new NGK BR8HSA sparkplug as recomended via the service manual. at same time try to get them to decamp carb and check mainjet size and order in a one size up and then have that fitted if the bike still shows a leaning out at top end/fueling starvation.

    start of november its a MOT (mine is for jan 27th or dec27th but unable to book in advance) so its got a full years ticket, then im looking for a sym symply 2 125cc if i can save up enough over winter or something thats not gonna keep draining my wallet.

    Meanwhile im house bound as i cant risk breaking down again.

    I know sym jets did have a problem with seals going and causing heating issues, but when we chopped out the rollers there was no sign of any leaking at all, no oil residue behind the variator it was spanking clean, and no lateral shifting in the crank or bouncing so thats all good the bearings are fine to. so those causes are marked of the listing.

    fan blades all intact to so its getting good airblow via the ac cooling unit on magneto, shroud is all clean to and cn feel the warm air venting from the vent holes in shroud itself. BUT one concern is the variator side case getting super hot i have a hot air leak somewhere or a binding problem but its not a belt-roller-clutch-gearbox issue or the bearings and seals.
    other possibility is piston blowback, heated gas making its way past the rings and into the crank case area, but i would expect bearings to fail and seals to degrade very fast due to a blowback issue ( i need to source a borescope so have a gander inside the cylinder and top of piston for possible damage/ leak signs)
     
  9. scubabiker

    scubabiker NITROJUNKIE

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    7,321
    im not sure that problem would come up on the dynomometer as it has the forced air induction thing.
    try disconnecting the pipe from the frame to airbox and see if it runs a little better?
     
  10. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    my thoughts to Scuba.

    i had the airbox apart last time gave the foam a good clean and re-treated with airfilter oil, but also noticed the restricter is still inside, i left it alone and still inplace, never had the carb open so cannot say what state thats in .
    The airbox breather tube is a pain to get at, removal of seat bucket and whole rear covers ( sides and rear tail are one unit), so i will decamp the breather tube direct from the airbox intake ( i dont mind cleaning the airfilter every couple weeks ), once upjetted a size i will dump that airbox restrictor rubber .

    pedro runs rich when starting up, got a nice plume but not over the top smoker , been looking for a capping plate so i can dump the oil feeder and go direct to tank mixing but nothing comes up ( pump fits into engine casing and runs of the crank), vac line also leads from crank casing to, oil is direct drip into inlet manifold on the crank casings.
     
  11. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    lol i have a scooter thats had 6 previous owners that had no clue on mechanical upkeep.

    when i drained the gearbox oil, it was blacker than Tar oil lol , yeah i even had to check twice i was removing the right bolts, the stuff that went in was honey coloured goodness all 110ml worth lol.
    i treated the rear box like it was a first service filling to 110ml, now in about three months time i will drain that sucker out and see what state its in then refill again to the spec'd 90ml

    its weird that manual says 110ml , then later on it says fill with 90ml , two differing numbers but both 100cc and 50cc have the same rear box. i am thinking more is better as its getting a extra good coating on the primarys and secondarys.

    last owner alloy foiled the leo vince tt rear can , and then went onto alloy foiling the front and rear brake leavers to, but never re-foiled the bottom of the seat bucket. when i removed that to re-fit a broken seat lock i found alloy foil hanging down onto electical cabling and the motor itself, i removed said foil but alas had nothing to replace it with either so its just bare plastic ( but aint melted just yet thank god lol).
    nearly all the body lugs are snapped and/or missing to , the poor scoot has been so mistreated that i have took it upon myself to set it right again.

    worse parts are, fuel gauge needle jumps up and down when you slap the indicators on, and the bikes candles ( headlights) get brighter when you rev it up and dull when you back off the gas. cannot find anything LED to replace those old school bulbs with as they need resistors and shizzle and electrical work on scoots is just a total head pain and brain ache.
    Good part, i have running lights and main lights switching ( musta got the upmarket version sym jet lol )
     
  12. Stevep

    Stevep Well-Known Member

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    5,895
    Don't overfill the gearbox, it'll force its way past the oil seals, soaking the clutch, belt and brakes.
     
  13. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    first service change it says 110ml, then after that 90ml , will keep an eye on rear drum brake if i feel it getting less grippy i will flush out the rear box and re-fill with less.

    i had to use a kiddies rabbit water bottle with the bottom hacked off and the ball bearing punched out of the tube to decant oil into the rear box, used a pyrex cooking measure to get the 110ml, but after filling i got about 100ml in give or take, as the fill hole and my make shift funel just didnt cut the mustard to well. wish they would do top fill and not side fill on these rear boxes lol its a darn headache.
     
  14. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    Bikes in with the mechanic today, fuel pump fitting and fuel filter. they also dropping the exhaust and checking the piston for score marks also running a compression test and pulling the carb off to check it ( i mentioned WOT could be a lean area so they checking needle and if its still got a stock main jet fitted)

    bike was de-restricted before i purchased it so i have no clue if it was re-jetted to compensate for the higher fuel uptake, its 100% derestricted as i have to hold it back when encountering hills otherwise it just starts to pick up more rpm and goes even faster to a point its boardering pure redline. just hope this pump - filter and carb check help, and also theres no scoring /compression loss from the piston. ( cannot see it being compression loss as kickstarter has a nice solid bite and feel from BDC to TDC, and starting via kick is a single or dual kick and it starts), one other area is the auto choke , unsure how long its been fitted or if its even working right so maybe a replacement of that also is on the cards.

    come to the point a 70cc kit is just not worth it so much hassle just for a 20cc increase so a sports 50cc kit would be a better choice and removes the stock cylinder and gives a tiny bit more power but still within legal requirements , something like the naraku 50cc cylinder but use a wossner or wiseco piston instead of the naraku piston that comes with the kits. i did think about a full derestriction on exhaust so to release the full power from the sports pipe but i think the motor would suffer and then a new carb etc etc required.
     
  15. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    Update:

    well works out the 101 octane fuel pump i got is useless only a dribble comes out of it, but good news the old pump is fine. carb has been looked at and some problems found, carbs float was bent so no wonder i was only getting a small amount of fuel draining from the bowl drain plug , thats been sorted out. just waiting on mech to get back from a test ride then i find out how much its costing me, hopeful my new fuel filter has been fitted to.

    added a naraku 50cc sport cylinder to my basket to keep on hold just incase the new fitted cylinder is borg'd , possible my hard break in was just to much for it, i very much doubt it but we shall see. also looked at a couple carbs incase i need to think about repalcing this stock one out at some time.
    i am in hope that bent carb float was the cause of WOT fuel starving / leaning out. ( i never took carb apart so its been like that a long time)
    Trying to find a alloy cutting hole saw, idea is to re-route the forced air intake to the variator cover and not the carb airbox intake then some crafty low slung 5mm drill holes to allow that hot air to escape and also any water that enters to drain, that should keep the variator side case cooler and not burning to the touch hot after running. i also need to bodge a fan onto the variator drive plate so it can circulate air around helping with cooling to. ( sure naraku did a after market drive plate with a fan blade fitting so need to check up on that )

    will know more in a while when i phone to see if bike is to be picked up ( first call was a how is everything going call as it went in this morning at 9:30am and heard nothing till i phoned at 3pm)
     
  16. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    Update finished !! well i hope so lol

    faults :

    carb needle held in place with two washers ( no needle clip what so ever ), throttle slide nipple not seated correctly so slide had to be modded and filled to shape. and needle clip added
    Airmix screw ( idle) fully wound in and seized, has been freed and set correctly.
    carb float bent out of place been reset to 8.8mm spec by manual
    fuel lines incorrect to restrictive , whole new fuel line been installed at correct bore for nipples.
    oil pump reset and adjusted to correct metering ( was way off)
    fuel filter installed and had to be removed and refitted after flushing through due to gunk inside it ( brand new filter that was)
    old fuel pump checked and refitted works a treat pumping fuel.
    new sparkie fitted ( stupid me took my spare out from seat and replaced with pump, DOHHHHNUT !!! )

    Total cost inc VAT £144.71p ( 3hr labour charge +fuel pipe and sparkie, but they worked on bike all day ).

    after picking up i took it to the bumpy road where i could replicate a fueling issue , its a back road country lane (bone shaker 40mph limit) bike ran faultless no hickup or wanting to bog down.
    BUT theres no change , still feels gutless to 30mph then goes like a 1000cc upto max rpm, throttle snap is less than it was, more smooth to hold a set speed but its snappyness has gone, but engine braking is better, back of the throttle and you feel the clutch dragging the rpm down to a point its slack and freewheeling.
    I dont trust it to go out on a big long ride so need to find myself a quiet 50mph road close to home so i can pin that throttle WOT and see what happens.
    3x 6g and 3x8g rollers just are not cutting the mustard looks like i need to lower the 8g rollers but i dont want to be going back to all 6's bike would top 42mph and just go no faster, where the 8gram shift now gives me 50mph (on the clocks), mech says its shifting to early (but i weigh 7st and he weighs like 15st)
    piston and bore are clean and my hard break in has done the trick bedded nicely no scoring or marking and no sign of blowback past rings.

    well its 24 days to the hallows ride out so plenty of time to see if pedro is going to break down, one downside is it went in with a full tank of fuel and came out with half a tank ( wouldnt be so bad if it was non premium in that tank, but 1.21 a lt hurts my wallet ), scooter now stands me into £300+ in just repairs/replacement and labour costing, thats more than its worth on insurance lol
     
  17. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    Well there is a big change.

    went for a run today and put around 30-40km on the clock , 40-50 mph zones and yes somewhat hard on the throttle for most of the time. got back home and expected the variator cover to be egg cooking temps but, i could hold my palm on it and keep it there, its was hot'ish but more a nice hot not burning to touch hot. and no issue with fuel starvation /lean at WOT , so the carb fiddle and the oil pump adjustment has solved the lean out and the overheat problems.

    BUT i really have got a variator tuning fault thats on my behalf, hills we are dropping to 20mph and its just not willing to pull , you can be wide open on a hill and it just drops off speed and revs. the mixture of 3x 6g and 3x 8g rollers just aint enough even for my light body weight of 7st.
    Now i did have all 6g rollers installed but the bike would rev high and bomb out at 42mph at max rpm, but with the current 8 and 6 roller setup i gained 8mph
    3x6 +3x8 - devided by 6 gives a running weight of 7g and a top speed of 50mph on the sym clocks.
    6x6 rollers gives a running weigh of 6g and a top speed of 42mph on the sym clocks

    now i deduce that if i fit 3x6 gram and 3x7gram rollers that gives me a 6.5g running weight and around a 4-5mph gain ? so a top speed fo somewhere between 45 -46 mph , i am loosing some mph somewhere but i cannot work out why and how with only a very small weight shift.
    Straight 6's gave me the best peak power kicking in at 30mph upto 42mph but it was screaming
    current setup gave me best max speed with peak power kicking in at around 37mph and pulling all the way to 50mph.
    new prototype setup of 6.5g (staggered 6's and 7's) would see me drop 4mph but maybe gain holding rpm on hills and less rpm drop off /speed loss on hills.

    this is the problem area the fine tuning of the variator, its a stock factory unit so the only other choice is a multivar 2000 but thats normaly something you would be throwing in when you have bore kitted up ? do you guys think i would get better hill pulling with a multivar or would it be better to drop the stock factory clutch and bell and run with something more sportwise setup ie a mallosi clutch and bell with some contra spring and main spring adjustment?
     
  18. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    yep after reading around the multivar 2000 is the choice to run with has better ramping and hopefuly run smoother on accel and a tad extra top end.

    went for a late night ride, nearly came of bike a few times. and its nothing to do mech wise or rider overdoing it, its those blooming candles, low bean i can barely make out the road ahead, high beam is just as bad. infact i couldnt get over 20mph without risk of stuffing bike into a hedge or riding through a corner straight on. its that bad it scared me i was butt clenching all the way home through the little back roads and on A-roads without lighting i was just blinded out by headlights from others.

    i looked at my bulbs and they are like something you find in a kiddies torch those yellow cast light bulbs. more so is the worry the bike is powering those lights from the generator ( not the battery) so its an AC source to. you have to keep above 3k on rpm just to keep them glowing, back off to idle and the lamps just flicker like fairy lights on an xmas tree. so thats another shell out from my already empty wallet.
    cannot fit HID as they will kill my generator drawing to much power ( a 35w hid will draw around 45w due to parasitic loss) and those halogen lamps are just going to be around the same as the ones i have installed now. the other problem is LED lamps run DC and im on an AC source.

    and i mean they are bad, not telling no fibs they are totally useless at night and i am amazed i have not been pulled over for poor headlamps by the local traffic police yet. so its a trip to the bike mech on monday to find out what i can do ( i also worry that its not going to pass the mot in november due to poor illumination ) , the rear tail light is the same very very dull untill you pin the rpm up, then when it idles the rear tail lamps just dull right out ( rear tail lights are also my licence plate lamp).
     
  19. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    they just upgrade lamps , i really need something thats going to light up the road not give me the same type of lighting i have. but a hid kit wont work and a led conversion i dont think will work either with the lamps being wired into the generator not the battery and being an AC source not a dc source.

    Hids draw to much juice, the converter will feed 30w to the lamps but itself will draw well over the 30w the bulb requires, led lamps are DC and not an AC source, and i am not sure they will run on the ac generator side ie be dull until the rpm is at a certain point , i live in a village but my travels take me out into none light roads that are pitch black and winding so i really need lamps that will show me where im going not give me a hint. ( youtube a lot of halogen v stock bulb reviews and most dont show a big difference at all over a stock bulb :( )

    bulb is a BA20 something, but in manual it says nothing and research pulls up a BAY20 something bulb its a 35/35w bulb to but god its totally rubbish my ciggy lighter does a better job lighting up the road
     
  20. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

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    i have kind of solved the AC problem.

    i take the AC feed and run it through a 50v 25w bridge rectifier , this converts the 12v ac input to around 17v dc output.
    now when you wire up your led lights you will notice they can make a buzzing sound and thats because the ac wave is still coming through, you will also notice the lights will flicker. the problem here is because the voltage is still a wave it needs filtering , so if i add a large capacitor to the pos and neg from the bridge rectifier this will smooth out the signal and halt the buzzing sound / light flicker problems. i also add a diode to stop the capacitor draining back into the regulator recifier - stator on the bike, if you dont it can cause other problems.

    so this had me thinking , the stock factory bulb filckers just like an led would because of that ac wave, my thought is to add a capacitor to the pos and neg on the bulbs power in leads and add a diode to stop back flow into the system. that should smooth out the stator wave signal and stop the flickering bulb syndrome ? BUT if this is the case why did the makers not do this in the first place , thats something i have to look into.

    i dont like electronics much but looks like its my best way to get a better headlamp system.
    looked at halogen and have found a few people having problems melting the bulb mounts over time , there is no way i can get around this as the sym jet basi x comes with a glass headlamp lens so no drilling vent holes/breather holes for cooling. will pop into shop on monday and see what the mech thinks of my bridge rectifier addition and if it will work.

    so something like this.

    alternating current into the BR - output from BR (pos side) into a diode and then to a large smoothing capacitor- from here we feed direct to the LED drivers and onto the lamps (lamps must be 9-30v as we gain a few extra volts from the ac-dc conversion)
     

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