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

Members Login
Post Info TOPIC: 350 clutch slipping under hard acceleration


Veteran Member

Status: Offline
Posts: 60
Date:
350 clutch slipping under hard acceleration
Permalink  
 


Hi guys,

I took my 350 on the road and the clutch was slipping under hard acceleration. Everything set according to specs, EBC heavy duty discs and springs, OE six disc basket. The basket has slight notching though. I feel too much power is lost there. What could be the cause? Anyone with a 350 having the same issue?



__________________


Super Guru

Status: Offline
Posts: 1248
Date:
Permalink  
 

It may just be that the 6 plate clutch is not enough, unfortunately. Let's face it - the 350 is significantly more torquey than the 250 the clutch was designed for, and Yamaha themselves changed to a 7 plate for the Blue 250s.

I have only fitted 350 kits to later motors with 7 plate clutches.
What gearing are you using?

Anyone else with a 4GY 350 care to chime-in?



-- Edited by mossproof on Sunday 19th of June 2022 04:54:33 PM

__________________


Veteran Member

Status: Offline
Posts: 60
Date:
Permalink  
 

I use stock gearing 14-44 Simon. That is a logical explanation, unfortunately though. The power loss from the rear wheel is significant. The issue is more noticeable when the engine gets hot.

__________________


Senior Member

Status: Offline
Posts: 304
Date:
Permalink  
 

I can't recall any slipping on a 6 plate 350

__________________

Thanks

Daniel Lee



Super Guru

Status: Offline
Posts: 2510
Date:
Permalink  
 

My clutch is a 7 plate, so can't comment, but if Dan is not having any issues with he's 6 plate, then maybe something is wrong with the clutch set up?

Maybe check it all over again Christos?

 



__________________

totallyttrs.com

 



Senior Member

Status: Offline
Posts: 304
Date:
Permalink  
 

I know my girlfriends bandit was a little sensitive to fully synthetic oil, changed back to semi and it was okay - probably not the issue but worth considering

__________________

Thanks

Daniel Lee



Veteran Member

Status: Offline
Posts: 60
Date:
Permalink  
 

Hi Steve, Dan, thanks for the input. Dan, I hope you've tried the sequence: upshift-WOT, upshift-WOT, on your six plate 350 without any slipping, gradual throttle twisting is flawless. I use Silkolene super 4 10w40 semi. I noticed that my clutch lever had marginal free play, readjusted it but without testing it yet. I cannot think of anything else. The issue was noticed only on hard acceleration on tarmac (I can't go WOT on the gravel roads anyway). Could be the clutch cable needed a bit of loosening...I'll let you know.

__________________


Super Guru

Status: Offline
Posts: 2510
Date:
Permalink  
 

Hopefully clutch adjustment will sort it, I had to adjust mine the other day, not for slipping but it had moved a bit and the bitting point was wrong. 



__________________

totallyttrs.com

 



Super Guru

Status: Offline
Posts: 1248
Date:
Permalink  
 

Stock gearing will cause more "leverage" than the more off-tar set ups I suspect Dan Steve and I are running (14/47 in my case)
I think you may have found the design limits of the OE clutch. You could try filing the ridges in the clutch basket, but I don't think it will help in this case.

__________________
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