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 -> difficult starting after rejetting carb
Post Info TOPIC: difficult starting after rejetting carb
engineer1949


Veteran Member

Status: Offline
Posts: 31
Date:
difficult starting after rejetting carb
Permalink  
 

i have an open enduro with derestricted exhaust and opened up air box jetted to suit the better breathing, now runs really well no hesitating just pulls well right through the range BUT starting is now not good with the original jets it started allmost immediatly with the choke button out ,now it needs several twists of the throttle to squirt fuel into the inlet track but once it fires up the choke does seem to have an effect as you have to keep the choke out for a few seconds then ease it in once the engine has a bit of heat, any suggestions with the fault much appreciated .   

 

 

john



__________________
JOHNYBOY


Super Guru

Status: Offline
Posts: 1102
Date:
Permalink  
 

tight valves

__________________
mossproof


Super Guru

Status: Offline
Posts: 1435
Date:
Permalink  
 

Suggests to me the pilot jet might be a bit small now. Could try opening the fuel screw a turn or 2 to see if it makes any difference. (Put a dab of paint on the fuel screw to make it easier to judge how many turns you've made)

__________________
engineer1949


Veteran Member

Status: Offline
Posts: 31
Date:
Permalink  
 

thanks for the replies sadly i dont think it is either of the suggested faults compression is exellent from cold and once started mixtures are spot on plus the pilot jet is slightly larger than the original so should be richer, must be a problem with the choke /enrichment devise but cant figure out what as all seems as it should be but clearly it isnt.


john

__________________
TTRfan


Super Guru

Status: Offline
Posts: 8606
Date:
Permalink  
 

When the engine is warm, what happens when you pull the choke out? If it nearly stalls the engine then it's working.



__________________

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/ 
engineer1949


Veteran Member

Status: Offline
Posts: 31
Date:
Permalink  
 

all sorted found it to be that after the carb rebuild the new needle jet closed earlier than the old one so fuel level was to low so much so the tube for the enrichment was not picking up fuel reset the level now all good plus more gfrunt low down.


john

__________________
mossproof


Super Guru

Status: Offline
Posts: 1435
Date:
Permalink  
 

Well found! We'll add that to the fund of knowledge

__________________
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.
The TTR250 FAQ web pages -> TTR250 -> Repairs and maintenance -> difficult starting after rejetting carb


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard