The 07 grizz 450 I just bought is running extremely lean. The plug is white. The dealer reluctantly moved my jet from a 131.3 to 135 with no difference. I plan to do the job myself. I would like to know what jet size you guys are running so that I can get in the ball game. Also any other tuning info would be appreciated. Also where can I find some info on this BSR 33 carb. Mikuni dosen't even list it. Thanks

 

are you running unleaded gas?

 

Yes 91 Octane

 

unleaded gas looks whiteish on plugs when running normal..are you having any other symptoms

 

If your airbox and air filter are stock, and your exhaust is stock, then its jetted fine.

 

When a plug is a brown paper sack type color is when you have it tuned in. A white color means lean. There is also no top end. At 3/4 throttle to full throttle there is no gain. I realize that yamaha sets their machines very lean to meet EPA standards but this is to lean. I am figuring probably a 150 jet but I don't want to spend a lot of money buying jets I can't use. I just need a good starting point.

 

jets are only round 5 bucks each

 

[img]i/expressions/face-icon-small-happy.gif[/img]I would go a-little big-rich and then jet down,to rich=fouled plug,to lean=siezed motor, not good when jets are about $5.00 each, get a few of them and set it the way you want, Lite to a darker brown=OK. James

 

Extra jets are good to have on hand for future upgrades (pipe, air filter...) anyway.

 

<div class="FTQUOTE"><begin quote>Originally posted by: acklinb

Yes 91 Octane</end quote></div>


way to high run the regular 86 or what ever your state has..I don't know the manual for your machine but I bet 91 Octane is way to high..