sharkbait

Something defo wrong if it wouldn't start from cold as I think the 315's are quite well known for starting 2/3rd kick - my '97 does anyway. New rings could only have helped the compression and in fact the owners book says that you should replace the piston every year! Sure you'll find another - the cool thing is that, apart from the forks and carb, the bikes didn't really change at all so you now know pretty much all you need.

This shows where the axhaust can wear.... and my patch to fix it.

Had a good go at the carb today. Cleaned it again and found the hidden jet underneath the pilot jet and it looked a bit blocked. Running better now, may do some more playing tomorrow. oh yeah, i tried running the bike without the 'hidden' jet and it was very rich, so I put it back. New plug arrives on monday so that may also help.

No the silencer. Mine had a hole in the side and I bought some 2mm ally sheet , cut a section out and riveted it in place. Easy fix and looks OK. I'll try and post a pic. I also replaced the silencer and fitted a new baffle tube as the original had rotted away. Slightly more tricky but fine all the same.

Cheers Wherry. When I got the bike it was 1.75 turns out so probably too rich.

Not bad, could be browner. Does the airscrew out make it leaner or richer?

Brilliant, thanks TS - great info and certainly the path I'll be taking I owe you one of these

Right... I've got looked at those at all. Would they cause a lumpy bottom end (missus)?

Don't take the sellers word for it if he says the cooling fan is OK! I did and it turned out that it was dying and has had to be replaced. Let the bike run for about 5 minutes and check that the fan starts - it can take a while.

I'm pretty rubbish with Carbs so need some pointers here. My '97 315 (with PHBH carb) is quite jerky at low revs - so if I'm moving slowly the bike will keep jumping forwards a little. Air screw is currently 1.5 turns out. On more open throttle it seems better. I've taken the carb off and cleaned it but may have missed something. I checked 3 jets (main, the short idle jet and the one up inside the 'tube') which looked OK. I did notice that one of the floats has some rub marks on it - no idea how it could have got these but they're there. Also the slide has some wear marks on the side, could these be the issue? Is it worth repairing or would I be better of trying to find a used PHBL?

Great project. Keep us up to date with pictures.

No worries Trickiest bit is squeezing the rings together while putting the barrel back on. Seems you need three hands!

I think your both right. Will fit new ones. I'll b a dab hand at stripping these things by the time I'm done

Little update. New piston arrived from Feetup this morning (great service). Fitted it this afternoon (as our electricity was off for maintenance) and the result is that it's much better. There is still a bit of a rattle so I now need to decide if I can live with this or send the barrel for replating which will cost

I doubt they'd help a noob like me but what do they do?

All good. left the skid plate on, tipped bike over and drained - not as messy as I thought it might be. I used some Halford ATF which comes in a 1L bottle with a nice flexible spout that's narrow enough to fit in the hole, so I was able to put the nozzle in before tipping the bottle up and pouring in the pre-measured 500ml with no drips.

Hi Clay. Well I've since removed the head to find Z9 on the piston. Caroline at Sandifords says put an A piston in but I've also spoken to Alan at feetup and he's been very helpful. Basically I can put a new piston in and get a potentially short term fix or replace barrel and piston with matched items and fix it long term. He's told me to measure the ring gap and piston/cylinder clearance and report back - he will then give me my options. Ring gap is 0.015 which I think is pretty big, not done the piston clearance yet. Not sure which way to go at the mo. Bike was cheap at

Ahhhh, fixed the picture Additional pic showing no other markings! Hope this helps.

I'll try and get the pic to display..... No other markings on the back of the cylinder.

Yes mate, took my girls down - I'm def in the white class! looked good though. Not found anything else yet but will keep looking - no idea why my pic isn't showing.

After hearing a couple of other 315's today my '97 bike seems very loud indeed with a top end rattle. I suspect its going to need a new piston but when i looked at the base of the barrel instead of seeing A, B or C all I can see is O. So now I don't know what to do. Anybody come across this before? Pic attached of the barrel.