jetting problems

[jordamkr4]

just re-jetted my 06 raptor 350 and put on a new yoshimura exuast system and now the head pipe get red hot! any idea what could be wrong?

 

[vestige019]

the only thing i could think of is that its running really lean but i dont kno much about jetting i just know that your engine burns hotter running lean

 

[klutchbuster350]

too lean, I bleieve you have to go with a higher jet.

 

[palerider]

What jet size did you go with on the pilot and main?

 

[jordamkr4]

i put a dj136 in the main and the kit didnt come with a pilot jet, i aslo put the needle on groove #3

 

[palerider]

Damn dynojet proprietary numbering system. What does that convert to for the stock numbering system?

The dynojet kit doesn't come with any pilot jets? Okay, why does it cost more than a GYT-R kit??

 

[jordamkr4]

i guess i dont know what you mean by the stock numdering system? but im thinking i have to big of a jet in, it said to use a dj128 unless you have a modified air box then you need to go 4 higher, so on the chart i counted for hight and it was a dj136, but i think i need a dj 132

 

[lucasislight]

does it glow red hot at idle while it warms up? or while riding? if its at idle you need a larger pilot, and while riding could be your main and/or needle are too lean.

 

[ratchracing]

I have the Yoshi pipe and my bike is jetted perfectly with a 150 main and position 2 on the needle, runs perfect but the header will still glow red when the bike is hot and just idiling. This happens because the Yoshi header is made of thinner steel than the stock header, therefore it gets hotter faster and glows red. Most 4 stroke MX bikes do this as well. Just re-jet so it runs right and forget about the header, but the header should not glow red while moving! If it does then you are WAYYYYY lean.

 

[palerider]

Lets start over. Put in the biggest jet you have that came in the kit. Take it on a wide open throttle run. It should stumble pretty bad. Now go down a jet size and do it again. Keep going down in size until the wot stumble goes away.

Now for the pilot jet. When you are adjusting your air mix as you turn it out the idle should pick up then start to go back down, put your screw at the highest smooth idle. If you have to go more than 3 1/2 turns out go the the next biggest pilot jet and start again.

After these are done you can fine tune it by doing plug chops.