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The TTR250 FAQ web pages -> TTR250 -> Feedback, suggestions, chat and general banter -> 263cc Finished - But Small Problem of a Tick / Ping / unidentified noise
Post Info TOPIC: 263cc Finished - But Small Problem of a Tick / Ping / unidentified noise
sammyttr


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263cc big bore
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Hello chaps am fitting a wossner 263cc piston has anybody else fitted this and noticed an improvement ? Has a fmf can to

 

Thanks Sam 



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Archershome


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Hi there just doing the same thing at the moment to mine...

My bike only had 120psi compression and improved a bit by adding a bit of oil...

So while apart I went for it

Along with new valve steam seals, clean ports and re lapped valves.

Will report back...

Running in seems to be a mystery 



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devon_rich


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I went +0.5mm With Wossner piston, not the full 263mm and mine wasn't really worn but had to take the head off as the plug thread was damaged.
Seems to have a little more power low down

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sammyttr


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Sweet it's having full once over with valves relapped, big bore, new cam chain and manual tensioner, new valve springs and seals and valve clearances too.

Can't wait

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TDVT


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sammyttr wrote:

Sweet it's having full once over with valves relapped, big bore, new cam chain and manual tensioner, new valve springs and seals and valve clearances too.

Can't wait

 Please share your impressions once you're back up & running. I had hoped to freshen up my motor over the past winter but didn't get there. I'd be interested to know how it goes.

 

 



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sammyttr


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I'll try mines not standard though with having Road wheels on it and gearing lower as a result should be fun.


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Archershome


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263cc Finished - But Small Problem of a Tick / Ping / unidentified noise
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Hi all, so the bike is now fitted with 263 piston, new valve seals and all clean.

So here we go with the advise from those that might know:

Bike started well, has done 30 miles after being warmed up fully, oil has been now changed been on another run. The bike has loads of power!! Awesome pulls like a train! No smoke and seems to run really well.

I have notice that I am getting a small tigging / Metallic trickling sound (pinging?) on acceleration - NOT on tick over or over run or under heavy load. It seems to happen mid throttle when loading gently - TICK TICK TICK!

Now could this be?

Piston hitting edge of head gasket, as piston is 74.95, and gasket is 75mm not much to play with only needs to off by 0.05mm and with the squish may be?

Piston Slap? Measured all when putting back together so unsure this is it. Was tight in bore!

Pinging?? - Had noticed bike gets very hot!! Hotter than before! Could it now be running lean! More air but not enough fuel? Higher compression could cause pinging!

Really unsure as seems to be running not to bad at all loads better than it did, stacks of compression compared to the 110psi I did have! 



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TTRfan


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Doubt that the piston is hitting the head gasket.

Pinking usually only occurs under load but if you think its running lean then raise the needle a clip and see if you have any improvement.

My guess is that its the valve gear. I had this with my 325 even the the clearances were within tolerance. I went up 5 on the exhaust shims (still within tolerance) and problem solved.

Brian



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Archershome


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Hi Brian, thanks for the reply I see you have merged the two topics THANK YOU...

What do you think the 0.5 up on the exhaust shims did to resolve the noise you had?

So this would be tighter gap between the cams and the buckets?

I am also going to look at higher octane fuel, yep running lean causing higher operating temperatures, along with the higher compression is a great recipe for pinging I believe?

Awesome forum, loving eking able to chat with fellow TTR owners

 

 



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TTRfan


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Going up a size on the shim reduces the clearance and got rid of my "ticking" noise wink



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sammyttr


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Am doing clearances before using bike as lapping valves and doing springs etc, 263 kit looks a good performance up grade then, what is the valve clearance tolerance?

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Fladdem


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When I first rebuilt mine, it sounded like a battered lawnmower, it turned out that somehow the chain tensioner had failed, so I went back in, with one off a bike someone was breaking on ebay and it then needed new chain guides because the old ones had been chewed up by the failed tensioner. That sorted that. The second time I tore into the engine, it was burning oil from the valve stem seals. I put it back together again and it is running very hot, exhaust glowingly hot, when left to tick-over, I think I need to re-jet. But the bike pulls like an animal, or as close to one as a TTR ever will, it feels stronger than a standard 2003 wr250f.

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Adam. 1993 Open Enduro: 14/48 Gearing, Uncorked, Twin-Air Filter, Snorkel Removed, 263cc Piston, Ported and Polished Head, Shorty Header, DG-O Silencer(Loudener!), 140 Mikuni Main, Standard Pilot, Bottom Needle Clip (Still A Touch Lean)
Archershome


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Update, not pinging as done jets and high octaine fuel still there. Going for the valve clearances like Brian has said later. Then have a look at chain tension.



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sammyttr


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Reason gone over kill with mine but now needs full strip down as little end was scoured, so new conrod, crank bearing, piston and rebore, new cam chain, manual cam chain tensioner, lap valves in, valve springs, valve clearances and shims if needs be.

Hopefully runs well once done :D



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TTRfan


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Valve clearance checking and adjustment guide here



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