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

funguseater · Newbie

2005 ttr250 bolt, leaking oil from L/H/S cylinder head ?

ttr steve · Super Guru

The part is a decompressor retaining bolt, there is not much oil pressure up there so you could try some sealant and don't try to tighten it up to much. Are you sure it is coming from the thread, as it normally leaks at the decompressor rubber plug.

Steve

Cubber · Super Guru

Welcome to the forum, Funguseater.

That bolt is for holding the decompressor, but the blue ones don't use it and has a rubber seal held in by the bolt.

As you've found, the seals, in time, start leaking .... hmm

So a better plug is sold by Totally TTRs (<click) which seals it permanently.

Not difficult.

Martyn

funguseater · Newbie

Great news. If I buy one of these plugs, is there anything else to remove from the bike apart from the bolt and washer. And does the original bolt/washer screw into this manufactured plug after its been pushed in? Apologies for my ignorance....!

Cubber · Super Guru

Funguseater,

CLICK THIS and all will be revealed on original seal.

The more worthwhile aluminium plug is fitted similarly.

Martyn

funguseater · Newbie

Thanks cubber.

Just read fitting instructions for the plug. My problem is that the small bolt won't tighten fully, probably over tightened in the past. Oil is coming out past the bolt/copper washer. Can it be helicoiled? Bolt thread looks ok.

-- Edited by funguseater on Sunday 13th of May 2018 09:19:51 PM

Cubber · Super Guru

In a word, yes it can be helicoiled - probably a better repair than tapping oversize too.

Then again, you could bodge it with Araldite, etc.

If yours doesn't use a decompressor then anything to stop the weeping will suffice.

Are you handy with aluminium welding?

Here's Brian's repair with a Totally TTR plug.

Martyn

funguseater · Newbie

Oh, I get it now ! Great news, think I will pull the trigger on purchase. It was only this issue that was holding me back. I reckon a smear of red hermotite would do the job. Got some in the garage...thanks for the explanations all :)