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

Members Login
Post Info TOPIC: no power over 80km/h


Senior Member

Status: Offline
Posts: 107
Date:
no power over 80km/h
Permalink  
 


Like the title says.  The bike has 0 power after 80km.  I had the carb apart and she was clean.  jets look clean too.  It was like this when it was purchased used....  Any ideas?



__________________


Senior Member

Status: Offline
Posts: 206
Date:
Permalink  
 

Do you mean it runs up to 80 and then just stays running at that level? Is the throttle opening up enough? Is there enough freedom to allow the throttle to move through it's full range>
John

__________________

1996 TTR 250 OE, 1996 YAMAHA WR 200, 1990 YAMAHA FZR 1000,2001 HONDA DEAUVILLE 650, 2005 TTR 250, 1998 Honda CR125R( in pieces) 1994 Kasawaski KX 250.



Senior Member

Status: Offline
Posts: 107
Date:
Permalink  
 

Ah, sorry. I should have given more info...

The throttle seems to have full range of motion. It's is as if there is no more petrol going to the engine...

__________________


Super Guru

Status: Offline
Posts: 8026
Date:
Permalink  
 

if you have the petrol tap open, do you have a good flow of petrol out of the float bowl drain screw when you slacken it off?



__________________

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/ 



Senior Member

Status: Offline
Posts: 206
Date:
Permalink  
 

Will it start as normal with choke when cold and start as normal when hot without a choke and rev as normal? You don't have an inline filter fitted that is restricting flow?

__________________

1996 TTR 250 OE, 1996 YAMAHA WR 200, 1990 YAMAHA FZR 1000,2001 HONDA DEAUVILLE 650, 2005 TTR 250, 1998 Honda CR125R( in pieces) 1994 Kasawaski KX 250.



Senior Member

Status: Offline
Posts: 107
Date:
Permalink  
 

Brian. Yup. Seems to have good flow...

John, she starts right up. With or without the choke. There is an aftermarket filter! I wonder if that could be it. I'll remove it and see if that helps.

__________________


Member

Status: Offline
Posts: 14
Date:
Permalink  
 

I had a similar problem when I hit 100, just stopped revving higher and no extra power. Modified the stardard exhaust so it would breathe better now it revs freely right though the throttle range and way better power.

__________________

Just enjoying life.

2010 TTR250 



Super Guru

Status: Offline
Posts: 8026
Date:
Permalink  
 

Blocked breather on the tank cap?



__________________

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: 26
Date:
Permalink  
 

Another item to check is the seal of the rubber engine intake joint between the carburetor and the engine. 



__________________

2000 Yamaha TT-R250 (mudbike) 

2005 Yamaha TT-R250 (cleanbike)

2007 Suzuki DR-Z400S

2017 KTM 1090 Adventure R



Super Guru

Status: Offline
Posts: 1001
Date:
Permalink  
 

I wonder if it is actually jetted right. What exhaust etc is on it, and what jets?

__________________


Senior Member

Status: Offline
Posts: 107
Date:
Permalink  
 

Ok. I have a confession. It's not a ttr... Please done hurt me...! If my partners Honda GB 250. I've got the same one. She replaced hers after blowing up the engine... Ya. She can ride really hard. She often rides and races with guys on bigger bikes!

Anyways. It's definitely not the breather tube. Jets are all standard. All 'gaskets' are in good condition. I'll take a look at the bike next week. I have a feeling it might be that fuel filter that the previous owner put in. If not I'll take out the carb again and take a look at it. It could be that the float bowl is not set right.

Thanks guys for your input. I was kind of stumped..

__________________


Senior Member

Status: Offline
Posts: 206
Date:
Permalink  
 

Indeed, the plot thickens. An intruder in our midst!! (only joking) Try it without the fuel filter and a clean air filter and the carb set as per normal if the engine is as standard with no modifications.



-- Edited by jasparach on Monday 30th of March 2020 03:39:54 PM

__________________

1996 TTR 250 OE, 1996 YAMAHA WR 200, 1990 YAMAHA FZR 1000,2001 HONDA DEAUVILLE 650, 2005 TTR 250, 1998 Honda CR125R( in pieces) 1994 Kasawaski KX 250.



Senior Member

Status: Offline
Posts: 107
Date:
Permalink  
 

Thanks Jas. I ll work on it tomorrow.

__________________
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