Hi, Merlin from Manchester here...

Hi,

I am from Manchester and have just inherited a 2007 Peugeot TKR Off-Road 50cc, WRC Edition that I had bought for my son last year after he's just upgraded to a 125. This bike had a lot of bad tinkering done to it before we bought it and now I plan to work through the bike, recondition the engine via a new barrel and piston, a Polini sports variator with new 6 gram rollers. a new drive belt to sort the transmission out ( I do like 'scalded cat' type acceleration ) and sort the electrics and cosmetics out, such as paint the Technigas sports exhaust that has gone rusty with some new high-temperature paint. It's got the older Trekker headlight fitted with a proper dip/main beam, instead of the original 'projector' lights that I thought were rubbish, although I do need to finish off wiring up the lights on/off switch that I was installing (a bit of mix and match from Peugeot handlebar switches), as I was surprised it was missing!

The bike is de-restricted and has a larger (21mm?) carburettor fitted to go with the exhaust. I have seen it go 'off the clock' in terms of top speed riding it myself, but at one point, my son fitted a K&N-type air filter to the bike instead of the stock one and in the really wet weather earlier this year, he ran through a large puddle and the engine ingested some water, which I think may have damaged/scored the piston and barrel slightly. The bike has dropped off to about 45MPH top speed but acceleration has gone flat, so I think the compression has dropped off, hence me replacing the barrel and carb.

I am an old-school biker at heart and used to tune two-strokes back in the late '70s /early '80s and raced in Moped Mayhem back then on a tuned Yamaha FSI-E that was great on the straight, but wouldn't take corners on the stock tyres and we ended up in the hay bales a lot!

This 'restoration' is going to be quite a therapeutic journey for me and will bring back old memories. I hope to be able to share tuning tips with you on here if I can help, although the advice is based on older technology!

 

welcome to the forum!

 

Thanks!

Modern two-strokes may be a little more complicated then they maybe should be, but the principles haven't changed. I'm happy to help anyone with diagnostic stuff, although my methods of testing might seem a little strange these days!

 

I've spent today fitting the new Polini variator and rollers, a new Athena belt, a new kickstart lever and a Naraku high power ignition coil.

The Trekker certainly starts better (it has always been hard to start ever since we got it last year, but my son never gave me time to work through the problem), but I suspect that the carb has been over jetted with a 72 size jet even with the 100cc exhaust and Malossi air filter in it, as it 'bogs down' when you open the throttle and won't pull away cleanly.

I had to tinker with the idle screw to get it to tick over and it was worse with the air box on. Once the choke came off, the revs actually climbed as the mixture got leaner and I had to adjust the idle screw back, so my guess is that it's set up way too rich and the choke makes it even worse.

The standard 50cc Gurtner carb has a 62 main jet, so I've ordered the 50 to 74 jet kit from AP and I'm going to try re-jetting to around 68 before playing with the needle height.

It does pull away a LOT better on the Polini though, very nice! It has 5.8 gram rollers fitted and might need some tinkering with the roller weights to get the best balance between acceleration and cruising speed.

The manual choke lever is a disappointment, as you can't get to it with the standard air box on! I've left the auto-choke on for now, even though I don't trust them 100%.

I still plan to remove the engine and replace a lot of parts, but for now, I just want to get a good set of base engine and carb settings before I change anything else.

 

Welcome along Merlin, i noticed a few of your replies in other threads and thought you were an old school spanner from some of the suggestions you put in. Like me, I bet you listen to an engine before attacking it don't you? Nice to see the old 'itch' has returned.

 

I do, you are absolutely right. The noises are usually a clue and like anything that is unwell, you look at the overall symptoms first, before going straight into surgery. You do develop a 'feel' for what is a healthy engine and what isn't.

Edit: I checked the needle height this afternoon and it's on the top groove, so the diagnosis is definitely an oversize jet.

 

Welcome Merlin. I'm an old biker too. First time on a ped though.
Loving every minute so far.

 

It's good, isn't it? I scored some wheels and tyres this weekend. A full set of Trekker wheels and tyres for £30 and another pair of rear Vee Rubber tyres with inner tubes for a tenner. Bargain Hunt win all round! The wheels are grey, but some paint prep, some white enamel and red pinstripe tape should get me a spare set of wheels for the TKR and the front wheel even has a good brake disc on it!

I think I'll keep one set of wheels with the Bridgestone Trail Wing knobbly tyre on the back, so that I can use them as Winter wheels, as the chunky tread might be useful in snow. It's currently on the front of the bike but it's actually a 130/90-10 tyre and the front should really be 120/80-10.

 

You need to get a profile picture up so we can see your ride.

 

My TKR is partly dismantled at the moment (and I'm not photographing a pile of bits just yet ) , but this is the same model as mine and is the standard of finish that I am aiming for. I've dumped the projector headlights though as they are crap and I've got the older Trekker one in it. I need to fit some 501 bulb holders inside the Trekker headlamp for side lights and then I've got the 100% legal three-stage lights (side-dip-main), complete with a number plate light at the back.

 

You should have bought that one. It looks in mint condition.

 

It should do - I think that's a showroom model! Google found it for me.

I'm looking for a new front panel for mine, as the brackets inside it that hold the headlamp in have been broken in the past and I've had to use some long screws fed through holes drilled in the panel to hold it in place for now. I'm hoping that a TKR/Trekker kit in red is done by TNT at some point, or I might have to get a white body kit and paint it Torero Red myself. If anyone has a Trekker front panel, please let me know.