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

Members Login
Username 
 
Password 
    Remember Me  
Post Info TOPIC: Too rich mixture but will stall otherwise


Veteran Member

Status: Offline
Posts: 33
Date:
Too rich mixture but will stall otherwise
Permalink  
 


Hello guys,

My bike is a 1996 Raid. A few days ago I had a fuel flow problem so today I cleaned the fuel tank and the carburetor. I found a huge amount of gunk clogging the fuel pipe and the needle valve seat, so I cleaned them out.

But once I reassembled the bike, there was no way to get it start and run unless I open the pilot screw to near max and tighten the throttle stop crew way up. The mixture was so rich that my whole house smells like gasoline. But if I don't do that, the bike stalls. 

What could be the problem? Could anyone help me out? Thanks!!



__________________


Super Guru

Status: Offline
Posts: 8414
Date:
Permalink  
 

Sounds like a bit of gunk has found its way into the pilot jet cry



__________________

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/ 



Veteran Member

Status: Offline
Posts: 33
Date:
Permalink  
 

I cleaned the jets very thoroughly with carb cleaner so I'm sure there is no more gunk inside.

I tried measuring the fuel level in the bowl and found it to be very low, at least 20mm below the gasket. Could a low fuel level cause this kind of problem?

Thanks.

__________________


Super Guru

Status: Offline
Posts: 8414
Date:
Permalink  
 

A low fuel level wouldn't explain the rich mixture confuse

Gotta be something obvious that I am missing.

What was the nature of the "fuel flow" problem you had?

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/ 



Veteran Member

Status: Offline
Posts: 33
Date:
Permalink  
 

Thanks Brian for the replies.

Before I cleaned the carb, it was like this:

In the morning, I could start without any problem, but the bike will only run for a while then stalls. After that, it was very difficult to start again. However, if I wait for a while then it starts. It was obvious that the fuel was not flowing well into the carb.

I will take out the carb again and adjust it according to the manual, to see how it goes.

I did a bit of research and according to internet sources, my bike shows symptoms of fuel flooding the carb. But the fuel level is so low!

__________________


Super Guru

Status: Offline
Posts: 8414
Date:
Permalink  
 

If the float needle was sticking down then the carb would flood and petrol flow out of the overflow confuse



__________________

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/ 



Veteran Member

Status: Offline
Posts: 33
Date:
Permalink  
 

I forgot to mention, there was also a lot of sputtering and uneven running as well as a strong smell of gasoline even at idle. The carb is also missing the check valve assembly according to the manual. I guess the previous owner tampered with it and lost it.

The float needle was fine, I checked by lifting the float then blew into the fuel pipe.

I'm truly puzzled. In my country there are not many motocross bikes so spare parts are scarce. Most mechanics are used to scooters so motocross mechanics are rare.

 



-- Edited by TTRVN on Tuesday 10th of February 2015 09:08:13 AM

__________________


Super Guru

Status: Offline
Posts: 2588
Date:
Permalink  
 

TTRVN wrote:


I'm truly puzzled. In my country there are not many motocross bikes ........


 

What country is that, TTRVN? confuse

Martyn



__________________

You're never too old to learn something stupid

East Budleigh. Devon



Veteran Member

Status: Offline
Posts: 33
Date:
Permalink  
 


Okay so obviously the carb was not the problem so I looked more carefully into the air filter and the air pipes.... and found a gaping hole in the air inlet pipe. The hole had teeth marks!! Time to buy some mouse traps....

I repaired the hole and now the bike runs fine. Love the TTR!

My name is Bao by the way. I'm Vietnamese.

Again, thanks Brian and Martyn for the comments. This forum is truly a friendly and helpful place for TTR250 lovers :)

Here is the old girl:

IMAG0612.jpg



-- Edited by TTRVN on Tuesday 10th of February 2015 11:54:11 AM

__________________


Super Guru

Status: Offline
Posts: 8414
Date:
Permalink  
 

LOL - some big mice you have there in Vietnam Boa - with strange appetites biggrinbiggrin

Good news that you have fixed it because I was out of ideas!

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/ 

Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard