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 -> Bike smoking when warmed up
Post Info TOPIC: Bike smoking when warmed up
meadus69


Member

Status: Offline
Posts: 12
Date:
Bike smoking when warmed up
Permalink  
 

Hi guys,

just got my 2005 Up and running after a tidy up in the workshop.

Starts lovely and runs well from cold. Left it to warm up to change the oil but once warm it smokes quite a bit, puffs as it is revved I would say white or blue. Im not sure how old the fuel is but I will change this. 

was thinking of doing a compression test, will this tell me if it is valves or rings? 

anyone else with any other ideas to check? 



__________________
meadus69


Member

Status: Offline
Posts: 12
Date:
Permalink  
 

Ok so warmed it up this evening to do a compression test. Smoking straight away from cold now.. I would say white smoke, filled the workshop within a minute so had to run it outside.
Took out plug and it looked oily.. (brand new plug so only run twice in workshop)
Carried out compression test holding throttle fully open and 170psi shown. So well within what it should be.
Tempted to give it a run on some fresh fuel and see if it clears.
Otherwise check Valve clearances?

Could it just be carbon deposits on valves letting in oil from it sitting not being used for 6months?

__________________
JOHNYBOY


Super Guru

Status: Offline
Posts: 1098
Date:
Permalink  
 

stem seals common good compression though

__________________
mossproof


Super Guru

Status: Offline
Posts: 1433
Date:
Permalink  
 

Definitely give it some fresh fuel anyway! Fuel will be quite stale in a plastic tank after 6 months.

What condition is the air filter in?

Could easily be stem seals as John suggests. I have just been rebuilding an old Honda TL250 with the same symptoms. Actually turned out to be a loose valve guide, but a hardened valve stem seal would allow oil past in the same way.

Good luck!

__________________
meadus69


Member

Status: Offline
Posts: 12
Date:
Permalink  
 

Air filter brand new twin air.

I started it again tonight after compression test, started instantly and stood idling for a good while with no smoke. As soon as I opened throttle it started smoking straight away and then continued.

I held it at 1/4 - 1/2 throttle for a few mins to get some heat into it and see if it would clear the smoke, downpipe was glowing cherry! I guess it is running lean? Will drain the fuel and take carb off and inspect it.

How hard of a job are stem seals?

__________________
mossproof


Super Guru

Status: Offline
Posts: 1433
Date:
Permalink  
 

I have heard glowing pipe can also be rich running - from fuel continued burning in the pipe instead of in the combustion chamber, but I don't know if it is true or just "internet diagnosis"
Stem seals - ok if you have the right tools, patience and general skills!

Brian's cylinder head rebuild sticky here: www.ttr250.com/Rebuilding_cylinder_head/TTR_cylinder_head_rebuild.htm
His cylinder head removal sticky here: www.ttr250.com/Removing_Cylinder_Head/TTR_head_removal.htm



__________________
TTRfan


Super Guru

Status: Offline
Posts: 8606
Date:
Permalink  
 

I have had a similar issue and spent ages messing about with the carb, etc.

Turns out TTRs don't run well on diesel and even a small remnant of it in your petrol tank or can can create quite a smoke haze!

Just a thought.......



__________________

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/ 
meadus69


Member

Status: Offline
Posts: 12
Date:
Permalink  
 

Thanks everyone, will start by changing fuel for fresh superunleaded, then will look at carb and stem seals.

__________________
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.
The TTR250 FAQ web pages -> TTR250 -> Repairs and maintenance -> Bike smoking when warmed up


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard