Couple of problems with my neos

Hi everyone, its been a long time since i have posted on the forum and i have been having a few problems with my yamaha neos.

My first problem started when i was riding home after work my drive belt snapped, replaced the drive belt and now my front pulley fan wont tighten up properly it has a little wiggle in it.

My second problem is with my carb, i replaced it recently with a moto force carb from pedparts and now my bike is refusing to start up.

any help will be appreciated

Thanks Furby

 

hi
for the belt, as you have found out, when the belt snaps you have to clean everything before reassembly. Then, when you go to tighten the variator, pinch the rear spring variator at the back to give you enough slack to tighten the variator without the belt interfering.
Also, have a read here and maybe get some washers:
http://www.pedparts.co.uk/blog/variator-fitting-crankshaft-pulley-spline-damage

For the carb, what kind of choke does it have? Manual or auto? How many turns (from closed) on the richness screw? What diameter is the carb and what kind of filter/ airbox are you using? Does the scoot go ok when running? And what is the main jet and what colour is the business end of the plug?

 

It sounds like the variator outer pulley was damaged when the belt snapped and as it's made of alloy, it would bend long before the crankshaft would. The centre of the pulley where it meets the crankshaft is damaged.

Take the outer pulley off, in fact take the whole variator off and check that the crankshaft isn't bent. Then get a new variator to replace it. Second hand or upgraded depends on your budget.

 

hmm- i've snapped a few belts in my time and i've never seen any damage. It's user rebuild probs I bet.

 

hi, i have done that with my variator when installing the new belt, i have also taken the belt off to reinstall the variator but still have got the wobble.

my carb is a moto force 17.5 manual 1.5 turns on the air screw with a dmp airbox when i got it running once, the rear wheel was constantly spinning no matter what i did to my idle screw. i have got a feeling it might be my inline fuel filter as when i use easy start to start it (only way i can get it started at the moment), i can see it drain out of the filter scoot stalls then it fills back up.

my spark plug is new so its not showing any signs for a plug chop yet.

thanks,

Furby

 

Hi
are you sure you have the depression pump hose connected to the carb right ?
Photos would be good. High revs indicates poor running - this could be anything.

Same for the variator - with a photo of the pulley snug and the end of the crank (but without the bolt).
How experienced are you with this kind of stuff ? Just askin' -

 

pretty sure everything connected up right, im quiet experienced but this has just confused me i have tried everything i can think of. will get some pics up tomorrow.

Thanks,

Furby

 

Unless the pulley is damaged - there is only one reason why you wouldn't be able to get the pulley on the shaft & tight. The width of the crank shaft exceeds that of the width of the variator assembly - and the shoulder of the crank (just behind the thread) is stopping the nut from bearing down on the kick ratchet & the pulley.
This can be solved with some washers between the kick ratchet and the pulley. Look at the photo link from ped parts again. On every scoot I have access to - I have never seen a variator that didn't require a washer somewhere to get the thing set up right- admittedly - I'm talking about after market variators & cranks.
This is why I have a packet of them in various widths from top perf.

For the carb - some photos of the installation would be good - but it sounds like a massive air leak - or no petrol getting into the bowl - for whatever reason.

Time to get the camera out !

 

Sorry the images are not very clear

 

good photos man ! Can't see anything wrong at all. Looks textbook. i would have a go with compressed air on the pilot jet/ circuit. Do you open the choke when you try & start it?
Can you get a pic of the variator minus pulley but snugged up by hand?

 

will get a pic of the variator tomorrow, today was ducking and weaving between the rain lol. i have tried to start with and with out the choke different air screw and idle positions its just not having it. Going to put the old carb back on i think but i have lost the needle spring clip.

 

ah. that might be it. with carbs- it's the little things.......
Bring on the pics of the variator.

 

sorry i haven't been on for a few days changed the carb back to the original and my scooters running, not been able to get a pic of the variator yet as it has been hammering it down when ever i have had free time. will try to get the pics up tomorrow depending on the weather

 

Did you re-fit the washer on after variator centre steel sleeve?

 

it didnt have a washer there, its got the sleeve, variator face plate, star washer, kick start gear, large washer and nut.

Here a pic of the first face plate after the belt snapped and the second one is after i replaced it (the belt hasnt been tighted up in the pic)

 

How is your idle? Still too high as before ? irregular perhaps? Are things any better with the old carb?
The fist pic is a mash up ! Star has disintegrated! Impressive!
Something wasn't tight. Did you look carefully at the 'this will strip/ this will not' link ?

 

it idles well but have always had a problem with the air screw its best at 1 1/2 turns to 2 no hesitation but it bogs and cuts as soon as i try to ride it, at 1/2 to 1 turn it runs ok but only hits 30 after bogging at 25 (fully derestricted)

yeah did have a good look at the link you gave me and the variator was on tight before it disintegrated, is it possible for the sleeve to wear down? only got the wobble when i replaced it with the new faceplate, think i will try putting a washer or two behind it as it does sit flush with the splines instead of slightly forward.

 

Have you tried a bigger jet? What size jet is in there now? What colour is the spark plug? did you upjet when you put the DMP airbox on? Never seen one but I assume it has increased air intake over a stock box.

 

Currently got a 90 jet in the carb for my airbox and my doppler exhaust which is being changed to a technigas q-tre when i get it derestricted.

The old spark plug is coked up which is showing to much petrol, but it wont run properly with more air?

Heres a picture of the dmp air box.

 

Isn't your Doppler exhaust already a derestricted one? I would have thought that the Doppler was a better exhaust than the Technigas one. Which model of Doppler have you got, so I can check if it's derestricted or not?