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

Members Login
Username 
 
Password 
    Remember Me  
The TTR250 FAQ web pages -> TTR250 -> Repairs and maintenance -> Crankcase breather
Post Info TOPIC: Crankcase breather
Gazztop


Member

Status: Offline
Posts: 10
Date:
Crankcase breather
Permalink  
 

 

Hi guys quick question for ya,I’ve just bought this bike and noticed it has a bad oil leak from the top end somewhere,I rode it briefly the other day and it was way too bad,it seemed to be leaking out at pressure,as if there is no crankcase breathers,so I go and investigate,and I can’t find one on there at all,all I see is this blank type plug where it should be,any ideas please people? Many thanks ,Gareth



Attachments
__________________
TTRfan


Super Guru

Status: Offline
Posts: 8565
Date:
Permalink  
 

Hi Gareth

The blue TTRs invariably have the breather on the camshaft cover.

It is very rare for a TTR to leak oil (in the way that classic Brit bikes do)  other than from the decompressor blanking plug just above the exhaust port.

See here

Brian



__________________

Exeter, Devon, UK

http://www.ttr250.com  - The one and only dedicated TTR250 FAQ!  

TIP: For easy viewing bookmark the "Recent Posts" view - http://ttr250.activeboard.com/p/recent/ 
Gazztop


Member

Status: Offline
Posts: 10
Date:
Permalink  
 

Hi Brian,thank you for your info it’s a great help,I just needed to make sure the previous owner(sss) hadn’t cowboyed anything just to cut corners etc,I thought this as there’s a blank in the inlet pipe from the air box to the carb (pictured) I’ve looked for info on this part but not been too successful yet, I’m guessing it’s some type of recirculating system,



Attachments
__________________
TTRfan


Super Guru

Status: Offline
Posts: 8565
Date:
Permalink  
 

You have guessed correctly - your airbox is missing the emulsifier - the "clean air" gubbins - see photo below:

Emulsifier 1.jpg



__________________

Exeter, Devon, UK

http://www.ttr250.com  - The one and only dedicated TTR250 FAQ!  

TIP: For easy viewing bookmark the "Recent Posts" view - http://ttr250.activeboard.com/p/recent/ 
TTRfan


Super Guru

Status: Offline
Posts: 8565
Date:
Permalink  
 

If you are unsure of any parts it is always worth looking at the fiche on Fowlers or other Yamaha parts dealers which have the exploded diagrams of all the parts.

This is the one for the airbox:

airbox_fiche.jpg

 

It would also be useful for you to grab a copy of the workshop manual. There are several freebies on the interwebs to download but see those available at Totally TTRs here. They are cheap enough and it supports the only specifically TTR250 parts shop that I know of wink

Brian



__________________

Exeter, Devon, UK

http://www.ttr250.com  - The one and only dedicated TTR250 FAQ!  

TIP: For easy viewing bookmark the "Recent Posts" view - http://ttr250.activeboard.com/p/recent/ 
mossproof


Super Guru

Status: Offline
Posts: 1385
Date:
Permalink  
 

The part that is missing/blanked off by a cowboy, is the resonator box, see here:

ttr250.activeboard.com/t51169250/yamaha-energy-induction-system-yeis-boost-bottle-air-chamber/

As Brian says, the most likely culprit for oil leaks is the decompressor blanking plug.

The cyclone/emulsifier is still there as far as I can see on your pic, and the long tube approx 14mm diameter that is attached to it goes to the breather at the top of the cam cover, which is where the crankcases breathe from on "Blue" bikes.



-- Edited by mossproof on Tuesday 5th of July 2022 10:59:25 AM



__________________
Gazztop


Member

Status: Offline
Posts: 10
Date:
Permalink  
 

Good morning and Thank you very much chaps,your info is most helpful,I’ll grab a copy of the workshop manual also,
With regards to this resonator box I’m missing,how important is it and should I try and source one or is it no big deal?
Thanks,Gareth

__________________
TTRfan


Super Guru

Status: Offline
Posts: 8565
Date:
Permalink  
 

Simon's eyesight is better than mine and he is, of course, absolutely right in that you are missing the resonator box disbelief

If you follow his link to the thread about the box then you will see that the informed opinion is that it is a Good Thing so worth getting ahold of one wink

If you contact Steve at Totally TTRs then I am sure he would be able to sort you out a good second-hand box biggrin

Brian



__________________

Exeter, Devon, UK

http://www.ttr250.com  - The one and only dedicated TTR250 FAQ!  

TIP: For easy viewing bookmark the "Recent Posts" view - http://ttr250.activeboard.com/p/recent/ 
KiwiJeff


Senior Member

Status: Offline
Posts: 125
Date:
Permalink  
 

When I bought my TTR that Box was missing and I thought it was not really needed.
Thinking that Mr. Yamaha had put it there for a reason so I bought one and put it back on and it seemed to give the bike better low down power.
I could be dreaming but .....
I was told that it probably had something to do with “Air Pulsing” on the Intake.
Cheers
Jeff


__________________
TTRfan


Super Guru

Status: Offline
Posts: 8565
Date:
Permalink  
 

Steve now has a resonator box in the shop - see here



__________________

Exeter, Devon, UK

http://www.ttr250.com  - The one and only dedicated TTR250 FAQ!  

TIP: For easy viewing bookmark the "Recent Posts" view - http://ttr250.activeboard.com/p/recent/ 
KiwiJeff


Senior Member

Status: Offline
Posts: 125
Date:
Permalink  
 

Thanks for that follow up Brian.
It’s good to know that I did the right thing by putting one back on.
Also, my feeling that the low down power was increased, looks correct.
Before I put it on, I did a Test Ride up a favourite local hill, where I have to change down at about the 3/4 mark but with it fitted the change down was further up the hill, or not needed at all.
Not a completely Scientific Test but works for me !
😬
All the best to you Steve and your families.
Might come back again one day to check out those Pasties 🥟 and Beer 🍺
Jeff



__________________
TTRfan


Super Guru

Status: Offline
Posts: 8565
Date:
Permalink  
 

KiwiJeff wrote:

All the best to you Steve and your families.
Might come back again one day to check out those Pasties 🥟 and Beer 🍺
Jeff

All well here thanks biggrin

Be good to see you again Jeff!

Brian



__________________

Exeter, Devon, UK

http://www.ttr250.com  - The one and only dedicated TTR250 FAQ!  

TIP: For easy viewing bookmark the "Recent Posts" view - http://ttr250.activeboard.com/p/recent/ 
ttr steve


Super Guru

Status: Offline
Posts: 2652
Date:
Permalink  
 

You would always be welcome here smilesmile



__________________

totallyttrs.com

 
KiwiJeff


Senior Member

Status: Offline
Posts: 125
Date:
Permalink  
 

Very kind Lads.

Just watched the TV News and you folks are getting some excellent temps at the moment.

Good time to be throwing those TTRs down some Devon Green Lanes. 🤪

Cheers

Jeff

 



__________________
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.
The TTR250 FAQ web pages -> TTR250 -> Repairs and maintenance -> Crankcase breather


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard