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

MikeBarnacle · Veteran Member

Sorry more oil leak posts!

TTRfan · Super Guru

It's almost certainly the decomp plug or bolt Mike.

See here for more info.

Should be a simple job to Helicoil the bolt.

Brian

petenz · Super Guru

Retap the 6mm bolt hole with a 1/4" UNC thread....
then loc tight the bolt in....
1/4" is 6.4mm

..

-- Edited by petenz on Tuesday 2nd of August 2016 11:11:20 AM

TTRfan · Super Guru

Does that mean you can re-use the original bolt Pete?

It is important if fitting a new aluminium plug to use it as it has the necessary locating pin of the right size and length.

If using a replacement rubber plug then it won't be an issue.

Briam

MikeBarnacle · Veteran Member

I've ordered both the new bolt and plug. Hopefully that will sort the issue. Cheers guys

ttr steve · Super Guru

Already in the post for you mike smile

petenz · Super Guru

TTRfan wrote:
Does that mean you can re-use the original bolt Pete?
It is important if fitting a new aluminium plug to use it as it has the necessary locating pin of the right size and length.
If using a replacement rubber plug then it won't be an issue.
Briam

No... you would have to use a 1/4" unc bolt to match the tread...

MikeBarnacle · Veteran Member

I've fitted the new plug tonight but the thread is completely shagged! Anyone helicoiled such a small hole before.....(that sounds so wrong!)

Am I best to get someone else to do the job or is it easily done?

-- Edited by MikeBarnacle on Wednesday 3rd of August 2016 10:21:37 PM

-- Edited by MikeBarnacle on Wednesday 3rd of August 2016 10:22:01 PM

pug · Guru

best look at getting a Time sert put in helicoils was good when that was all you could get but time serts have gone one better

Pug

Paul C · Veteran Member

My variation of the plug. I thought I'd quite like some easy way of pulling it out (then I'll probably never need to).

TTRfan · Super Guru

Interesting mod! biggrin biggrin

I recollect a customer sending me a photo of a children's toy which had an incredibly strong sucker on its base that he used to remove the aluminium plug without taking the cam cover off - will try and find it!

Brian

Paul C · Veteran Member

You could try a small valve regrinding sucker/tool?

TTRfan · Super Guru

Thanks to Olly for sending me photos of his special aluminium plug removal tools - strong little suckers biggrin biggrin

Removal toy 1.jpg

Removal toy 2.jpg

MikeBarnacle · Veteran Member

*****UPDATE TIME*****

So I've done about 250 miles since the bikes fixed and was all good, today though it's decided to chuck a lot of oil yet again! I'm thinking of opening it up again and using gasket sealant behind the new plug. I had to have to bolt" helicoiled" is it safe to remove the bolt that's been put in?

Or is there another solution. Getting frustrated with the silly bolt!

ttr steve · Super Guru

Hi Mike

you can remove a helicoiled bolt as normal, just to confirm that is that where it is leaking oil? Can you not put it back in using sealant? Have you tried Tiger seal before?

Steve

TTRfan · Super Guru

The aluminium plugs are normally a 100% fix. Could it be possible that you scored the hole in the head when removing the old plug which has allowed the O ring to leak Mike?

ttr steve · Super Guru

If the oil is leaking from the retaining bolt then the plug and rubber are not at fault, would that be correct?

MikeBarnacle · Veteran Member

I think it's possible I've gone a bit hamfisted on the hole (insert innuendo here)
I've used gasket sealant on the hole as well as the plug. Hopefully it will be all good after this. Just have to make sure I leave it a few days to set correctly.

Slightly different note, I need a new chain.....easy to buy and fit or will I need some major hardware to fit it or am I best to take it to a proper mechanics to do and have it done properly first time.

ttr steve · Super Guru

Hi Mike

Which chain?

MikeBarnacle · Veteran Member

Drive chain.

ttr steve · Super Guru

Give me a call and I will show you how smile

MikeBarnacle · Veteran Member

pm Me your number please Steve. Will obviously need to source a chain, here your the man nowa days.

ttr steve · Super Guru

We have chains on the shelf smile

Pm sent