Author Topic: 05 YZ250 jetting (Read 6172 times)

Stusmoke · « **Reply #15 on:** June 10, 2012, 03:06:11 AM »

I made the same mistake friend... I bought a CRF250R, it grenaded within 10 hours of riding. I'm still parting the POS out. Anyway as soon as I drove out the gate on my YZ250 I was sold on 2 strokes for life

scotty dog · « **Reply #16 on:** June 10, 2012, 11:14:27 PM »

a nice tan/brown colour is spot on, Grey/White is lean and black & oily is rich. Glad ya got it goin good, a well jetted bike is great to ride

Stusmoke · « **Reply #17 on:** June 11, 2012, 07:44:28 AM »

Clarify something for me cos I've heard six thousand mixed opinions.

If I say a mixture is rich does that mean its got alot of oil in it? or its rich in fuel?

I was always under the impression that a rich mixture had alot of oil in it

TMKIWI · « **Reply #18 on:** June 11, 2012, 09:24:37 AM »

Rich mixture is rich in fuel.

Stusmoke · « **Reply #19 on:** June 11, 2012, 11:08:08 AM »

I couldn't decide hey, peopel saying the opposite things left right and centre

riffraff · « **Reply #20 on:** June 11, 2012, 02:45:03 PM »

Quote from: TMKIWI on June 11, 2012, 04:24:37 PM

Rich mixture is rich in fuel.

x2

teampryor · « **Reply #21 on:** June 11, 2012, 11:00:44 PM »

Yes a high fuel to air ratio is rich
Not a high fuel to oil ratio that should be constant, at 32:1 or appropriate ratio.

Recovered · « **Reply #22 on:** June 11, 2012, 11:12:18 PM »

Pro Circuit does suggest to go 1 leaner on the main jet useing there exhausts

arnego2 · « **Reply #23 on:** June 14, 2012, 09:45:48 PM »

I would not rely just on the spark plug color, the head give you the idea where your jetting is.
And if the jetting is correct you would have a pool in the crank ca. 1 to 2mm of premix oil.

Advance timing makes the spark plug gray. I get a dark gray plug color but the head plus the pool in the crank tells me thet the jetting is correct. When ride harder and harder most people forget that they run the engine higher and need to put the jetting in the area of racing jetting.

Stusmoke · « **Reply #24 on:** June 15, 2012, 12:48:37 AM »

I hate to steal someones thread but my bike has ALOT of unburnt fuel/oil coming out the pipe and the exhaust port, I really need reseat the springs and seals on the exhaust port I'm hoping that will fix that part. But theres still ALOT of it coming out. Theres pools on the floor of my garage. Its so much it drips onto the swing arm then flows down to the back wheel from there. Thoughts? I was thinking fuel/air mixture but When I try to thin it out the smoke goes white.

arnego2 · « **Reply #25 on:** June 15, 2012, 11:09:09 PM »

Ok but how do ride they bike hard or not hard, fast meaning th e 3 rd gear at less the half wot?

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Author Topic: 05 YZ250 jetting (Read 6172 times)

Recovered