A forum for owners of Yamaha TTR250 trail and enduro bikes!

Hi brian,

Thanks for the reply.

I would have suggested the same thing as you regarding the notches in the clutch fingers if it weren't for the fact the I had read about these on this forum somewhere else and as such, I meticulously filed away all my notches on both sides of the fingers as part of my rebuild. They were super slick I believe when I assembled it.

If I have missed some notches (or left the surfaces too rough maybe?), and it was still the notched fingers, would it be plausible that this would affect all gear changes. I'm going to ride the bike to work tomorrow and will investigate if this behaviour happens just from neutral to first or whether it happens from neutral to second as well. Will also see what happens if I shift from neutral into second then down into first all in the one clutch lever pull.

Annoyingly, whilst Anna was riding the bike today pottering around town, she reported no such jerky behaviour so looks like I have an intermittent fault on my hands. My favourite.

325 wise, all good I suppose so far, but then I had a cylinder head rebuild at the same time, as my valve compression was shot so it's hard to tell what's made the engine better.

But it is definitely better. Looking forward to completing the run in and seeing exactly how much better! Will let you know...

Cheers!

Hi Howard

Sorry to hear of your problems, something is wrong in your clutch, as the friction plates have worn where your arrow is. I have just taken a picture of a new friction plate, so you can see the difference.

Not sure why yours has worn at the bottom??

Will try and have a look at a clutch tomorrow for you.

Hi Steve, yes they appear to be all like that, they all have that slight rim of wear, but the rim is concentric - i.e. on the opposite side of each ring, there is no wear, and the wear increases in both directions evenly around the ring. 1mm max depth of wear. I can see what all of the clutch plates would be rubbing on though as they each have their own steel plate to grip against.

Oddly though, I did check the clutch plates that came out of the replacement 7 plate clutch pack that I bought from yourself, and they also had that funny wear ring. Maybe just an oddity from a certain manufacture of clutch plates? 

Once I had reassembled the engine last night I checked for oil pressure.

Not even a drop of oil came out from the check hole above the filter. So I am going to strip again right now and check my oil pathways from sump to filter housing. Something doesn't seem right. Last time I took that screw out, I was cleaning up oil for 5 minutes!

Has anyone ever had an oil pump that hasn't primed or got an airlock? I'll check the oil cooler bolt, pump operation, pump gasket, pump o-ring and oil paths for blockages.

Is the oil pressure relief valve ever a problem?

Many thanks for the replies.  It's nice to know TTR owners are never alone!

Well after another late morning in the garage, ive cracked it.

And I'm ashamed to admit it was all my own fault, and as penance, I'll share my blunder with you all.

Basically, due to mounting costs for the engine head rebuild and 325 kit, I was too tight to buy a genuine oil pump gasket. 

I had made my own out of gasket paper, but somehow had managed to omit the hole that the pump sucks up oil through, despite marking out the hole on the paper ready to be punched.

Testament to the pump however, it had managed to suck some oil through the paper and still pump it up to the head. Stripped the pump apart, and it was oily inside and no undue scoring of the pump lobes. I made sure I had oiled pooled around the exhaust cam followers right after rebuilding the engine and running it for a few minutes, and this time round after the run in period. But now I've got full flow I'll keep an eye on it.

Made a new gasket, correctly this time, and after rebuild, I now have oil streaming out of the check screw and have bled the air out.

Still without tearing off the head, I won't know if I've done any damage to the cylinder bore. Time to invest in a boroscope.

Will take her for a spin soon and see how she feels.

Thanks for all the suggestions, sorry it was such a stupid mistake rather than a genuine engineering reason!

Learnt my lesson!

Hmm, strange this friction plate wear mark. 

Perhaps it did happen in my engine. I can't remember which set of friction plates I decided to use in my 325 build - the ones that came with your clutch unit or my original ones. However I do know that I only used the clutch boss from the clutch I got from you, as I had already filed away the notes on my clutch basket and didnt want to do it again on the basket that came with your clutch.

So maybe there is something wrong with my original clutch basket? 

Clutch is working wonderfully now though, during my rather spirited commute to work this evening, so it may be a while before I find out.

I might buy another set of friction plates and monitor their wear in my clutch/engine. Bit of a mystery....

On that note though, the original title of my post about the jerky 1st gear has now completely disappeared since the engine is getting the right amount of oil.

The new 325 engine put quite a few smiles on my face tonight - shes like a new bike since the rebuild. Loving the extra torque! Probably half due to the extra ccs and half to a reconditioned head. Shame she's not my bike! But Anna will be sure to enjoy her at our upcoming TRF meets.

Maybe time to sell my XT600 Tenere and buy myself a TTR250!

I'd love to have my own 325 and then go all out and fit a megasquirt injection system and some modified camshafts. Love a project!