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Green Hornet wrote:Was it cold outside? Cold air = more o2= more power. Once the bikes engine reaches operating temp, the engine should be LESS ABRUPT. I don't think it oil/ gas separation, unless you use a Castor Based Premix.

I checked the KIPS on my bike today and they all move easily. It was about 65 degrees outside when I rode it, I let it warm up first of course. The powerband mellowed out after I took it offroad. I'm starting to think it's a jetting issue, but correct me if I'm wrong. It had a pretty bad/dirty air filter and the stock pipe and silencer when I got it and have changed them out with a new UNI filter and FMF full exhaust

People also mistake lack of power for wheelspin.

I wasn't spinning the wheel though. There was definitely a noticeable power difference when I rode it, I don't know what's up. Maybe I was just running a little lean at the moment and need to re-jet it.

KDXrider1989 wrote:

I checked the KIPS on my bike today and they all move easily. It was about 65 degrees outside when I rode it, I let it warm up first of course. The powerband mellowed out after I took it offroad. I'm starting to think it's a jetting issue, but correct me if I'm wrong. It had a pretty bad/dirty air filter and the stock pipe and silencer when I got it and have changed them out with a new UNI filter and FMF full exhaust

Hmm. Now we might be getting somewhere... You are probably jetted very rich - when the engine is cold, it wants that rich mixture, and it may run great. When the engine warms up, though, it will run very sluggish.

What jetting would you suggest? The UNI air filter and FMF exhaust are the only performance mods on the bike that I know of, maybe a Wiseco piston. I never bothered looking at my current jetting ever since I got the bike, also I plan on getting Power Reeds soon

Suggesting jetting can be a slippery slope, but I think that this might get you close -
Summer: Main jet 155, Pilot jet 42
Winter : Main jet 160, Pilot jet 45

gregp wrote:Suggesting jetting can be a slippery slope, but I think that this might get you close -
Summer: Main jet 155, Pilot jet 42
Winter : Main jet 160, Pilot jet 45

Looks pretty fat unless you are riding sea level at the sand dunes

FAT is safe though....

Mr. Wibbens wrote:

gregp wrote:Suggesting jetting can be a slippery slope, but I think that this might get you close -
Summer: Main jet 155, Pilot jet 42
Winter : Main jet 160, Pilot jet 45

Looks pretty fat unless you are riding sea level at the sand dunes

Thats about where I'm at and I ride between 1000-3000 ft. Jetting can be a pain in the a$$ so haveing a good starting point helps.

Mr. Wibbens wrote:

gregp wrote:Suggesting jetting can be a slippery slope, but I think that this might get you close -
Summer: Main jet 155, Pilot jet 42
Winter : Main jet 160, Pilot jet 45

Looks pretty fat unless you are riding sea level at the sand dunes

I'm pretty close to sea level here in Southeastern Texas, so I guess I'll try this

People also mistake lack of power for wheelspin

LOL. I was guilty of that over the weekend w/ a snowmobile. Spent all day on clutch, took it out. "****, it's slipping some on the big end" Then I hit a section of packed snow, and it stood up 3', and almost threw me off the back...LOL. Once back in fresh snow I looked behind me, and noticed the 50+' rooster tail.

I finally got the chance to check out my carb jetting last weekend and found out I have a 152 main and a 48 pilot. I don't think I previously stated this, but the bike currently has a full FMF exhaust, UNI air filter, and I plan on getting 607's soon. Would the main and pilot jets and needle position/taper be the only things in the carb I would have to switch?

Pretty much, yes. Unless you air screw is way off. This screw is located on the left hand side of the cab, behind the slide, right where the air box boot attaches to the carb. It should be 1 1/2 - 2 1/2 turns out from fully closed.

Your jetting definately does not look rich, though. It sounds like you may have to start digging in to things a bit. You may have severe carbon build up in the power valve/exhaust port area, or even need a top end, but your symptoms are a bit mysterious. Is Fuel flowing to the carb Ok? Tank vent clear?

I checked out Inda's jetting guide and he said to raise the idle a bit and turn out the air screw until it's at its fastest idle. He said I'd be good if I'm in the 1 1/2 to 2 1/2 range like you said, but I'm at 3 1/2 to 4. I'm at 175 psi in the top end which is very good, power valves move in and out pretty good but I might reconsider cleaning things up a bit, fuel flows good, tank vent is clear, I never foul plugs, in fact the plug barely has any residue on it when I take it out. It feels very flat from upper mid-range to top end. I bought the bike when it had an old, dirty air filter and the stock exhaust and have since then replaced them, which leads me to believe that my current jetting is a bit lean

also it doesn't smell like a properly-tuned 2 stroke

i really doubt its the fuel, 2-stroke mixes very well in petrol and the second its mixed it never seperates. id imagine the problem is probably carb flooding/splash

moto_psycho wrote:i really doubt its the fuel, 2-stroke mixes very well in petrol and the second its mixed it never seperates. id imagine the problem is probably carb flooding/splash

Do what? Your information is not correct. 2 stroke oil, especially castor based oils, are quite prone to separation. Not saying I think fuel is at fault in this case... just saying.

KDXrider1989 wrote:I checked out Inda's jetting guide and he said to raise the idle a bit and turn out the air screw until it's at its fastest idle. He said I'd be good if I'm in the 1 1/2 to 2 1/2 range like you said, but I'm at 3 1/2 to 4. I'm at 175 psi in the top end which is very good, power valves move in and out pretty good but I might reconsider cleaning things up a bit, fuel flows good, tank vent is clear, I never foul plugs, in fact the plug barely has any residue on it when I take it out. It feels very flat from upper mid-range to top end. I bought the bike when it had an old, dirty air filter and the stock exhaust and have since then replaced them, which leads me to believe that my current jetting is a bit lean

That's a lot of "out" on the air screw. Try a leaner pilot jet.

Agreed. At 3.5 - 4 turns you are probably a couple sizes to large on the pilot. If the pilot is that rich, it is likely that the main is as well. Follow the rest of the jetting guide.