Dirt Rider . Net Text Version Home
Pages: 1
yz 250F Jetting Problems
(Click here to view the original thread with full colors/images)
Posted by: Zenith---------------------
I just bought a second hand 2002 250F last tuesday, i was out at a practice track today(for the first time), all was fine until it cut out going into a coner(i had done about 2 hours riding on the track before this happened) it took me 15 min to start it and it wouldn't idle, i brought it to a guy who had another 250f, he turned the idle up and said it was ok. Later i gave a friend a spin on it, he did 2 slow laps then came in, the same thing happened again, i was told to take out the spark plug and have a look... the insulator was white, but there was carbon deposits on all the rest of the plug(except where the spark jumps). I was told that it was running too rich and to move the clip up a position on the needle, is this right???
As this is my first time using a four-stroke i don't want to do anything that may damage it.
ANY help would much appreciated.
Thanks Robert
Posted by: Zenith---------------------
Any input would be appreciated...
Posted by: yzeater---------------------
Can I ask how the F feels in comparison to the EG ported CR?
Posted by: Zenith---------------------
That was actually my brother posting with my name so I still have the CR... I havn't had much of a chance to ride the 250 yet but I don't really think it has much more power then the 125, it is just a bit more usable. I won't change to 4 stroke yet but it won't bother me much when 2 strokes disappear and I'm forced to...
Posted by: dmp437---------------------
Check your private messages.
Posted by: Zenith---------------------
Can somebody explain the differences with jetting a four stroke to doing a 125 2 stroke please? Specifically what are the symtoms of Lean to watch out for and where in the throttle range do the particular jets effect, and what are the 2 jets that look like 2 slow jets?
On the 125 I would slow right down then crack the throttle full open and keep going richer until the bog went away. I did this on the 250F yesterday and it bogged and nearly died, does this mean it is lean or should it be like this? Also which jet should I be changing to effect this? There are 40, 7(something) and 178 jets in it now.
Thanks very much for any suggestions,
Philip
Posted by: dmp437---------------------
The 40 is your pilot jet, the 178 is your main jet. Check out www.thumpertalk.com in the Yamaha 250F forum. There are several very knowledgeable people there who can answer any questions you may have. An example can be found at JETTING INFO HERE
Posted by: Zenith---------------------
Thanks for the link I hadn't found anything there before because I had only looked briefly...
Thanks,
Text Version Home
vBulletin Copyright ©2000 - 2009,
Jelsoft Enterprises Limited.
vB Easy Archive Final ©2000 - 2009
- Created by Stefan "Xenon" Kaeser
