Standard bore with a 200 main jet?

[jchevy]

I went to the dunes this weekend and with my standard bore 10.5:1 ross piston, slip on e-sieries, uni filter with no air box lid and also a stage 1 hotcam, i was running a 200 main jet. needle is down one notch and a 40 pilot. My plug looked perfect so i didnt try any other jets. But can that be right. Bike seemed to be running good, but my buddy with a 426 was only running a 170.

Does the plug ever lie?

[3x440ex]

you should be running about a 165 main jet.....pump gas will sometimes give a false reading. good luck
;)

[DGR Designs]

yea man 200 sounds a tad high to me:eek: try around 175 or so. unles you take off your airbox

[TRX_Thumper]

yeah it does sound high...but if it aint cutting out at full throttle...it aint rich....just like i run a 150 in my 300ex...stock is 122.....and with a 400ex carb on mine i run in the 160's

[jchevy]

If im running a 200 main and i actually need all that gas shouldnt i be beating another bike with the same gearing that is running a 170?

My friends 426 was running 170 main and he was beating me by a little bit. If both bikes are jetted correctly shouldnt the one using more fuel be the faster one? Assuming equal riders?

[RAPTORAZ]

I went through the same thing last time at Glamis. I got all the way up to a 205 main and the plug still looked lean. However I noticed that the farther I went past a 170, the more sluggish the engine got at lower RPM. Which indicated that it was actually running rich. I ended up going with a 170 and it ran perfect all weekend. From the bottom of the RPM to the top. No hiccups or overheating. What I learned from my experience was to ignore what the plug says and just listen to what the engine wants.

[3x440ex]

if.... let say you had your head flowed, and you had a bigger exhaust like a e-series pro meg ( theyhave big headers) you would be getting maximum air flow then....that would take about a 175 maybe even a 180 if it's freezing outside. If i were you i would put the 165 in it and see how it does with that. if it pops alot when you let off the throtle and the motor feels hot then move up to a 170. if you want to check by using the plug then you should use a fuel with no lead in it like cam2 or VP racing fuel.

more fuel does mean more power but only if you have enough air to go with it..other wise you're going to run rich and that will slow you down.

you may have a leak though.....check around your intake boot ( spray some starting flued on it while its running.if it reves up you have a leak) good luck...

[OutlawEX]

i was running a 220 main after i got mine ported,cam,valves,pistion..And it ran strong...