Jump to content
Sign in to follow this  

Starting trouble

Recommended Posts

First off let me say that i have used the search feature but still haven't

found a solution.

I'll start at the beginning. Earlier this week i rebuilt my top end on my 2007 wr250f. I put in a vertex 13.5:1 piston, replaced all intake valves, new head, hotcams stg 1 intake and stg 2 exhaust. I also put in a jd jet kit.

My problem: the bike is a pita to start hot or cold. Once running it runs great but if stalled i can hardly get it going again.

Jetting:

Main: 180 (as per instruction when i called jd)

Needle: blue 4th notch (as per instruction when i called jd)

Pilot: 45

Leak:60

Fuel screw: has little effect when screwed in all the way so will go leaner on pilot

Possible solutions? not stall or shut it off (very unlikely for me). Smaller pilot ( already doing this).

Valves too tight ( checked them today and all in spec)

I am really at a loss for ideas so please help me get goin' again

Share this post


Link to post
Share on other sites

Just a guess, but your settings sound a little on the rich side to me.

Only make one change at a time and test.

One size smaller on the pilot is definately in the works since fuel screw all the way in doesn't affect it.

JD is tops on jetting.  I've tried the other guys, not nearly as happy as I am with the JD setup.

Share this post


Link to post
Share on other sites

when i put your data into the spreadsheet (and yes i am one of the few on the planet with the red and blue needles IN the spreadsheet) you are very very rich for your fsw.

 

you need to think 40 or even 38 PJ

and anywhere from 170 to 168 to 165 MJ

and while it might work at clip 4 you maybe need to try clip 3 too.

 

but 1st i would do just the 40 or 38 PJ and go from there.

Share this post


Link to post
Share on other sites

Well today i got about buying those pilots. I started with the 42 but it made only little difference with the fuel screw. I then put in the 40 and got it right at about 1 turn out on the fuel screw.

The best news is that the bike started ALOT easier hot and sitting at ambient temp.

I now need to know which to start messing with first: the needle or the main jet.

Thanks

Share this post


Link to post
Share on other sites

Today i got around to messing with the main and needle. I went down to a 175 main and the needle on clip 3. To my surprise it started even better, i only had to give a small amount of throttle cold and pull in the hotstart when hot.

This is great but some new things popped up. The pilot circuit is now too rich (fuel screw in all the way with small change). Also there is a small amount of bog that lessens as the bike warms up but is there a bit nonetheless.

I will put in the 38 pilot to fix that problem and try a 170 main. Any other advice?

Share this post


Link to post
Share on other sites

Well, i got it to where i think I'll leave it. I felt that mid part of the power was a hole and it wouldnt pull real hard. This was with a 165 main and blue needle on 3rd clip. I tried the red needle and it seemed to do a better job in that area.

Thanks for all the advice

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×