Another Jetting Issue?

[quadman21]

I just installed my Hotcams cam and an UNI air filter. The quad just felt dead. Not a lot of power. So I dropped the needle by one position and it got better but by two positions it just cuts out on top. I looked at the plug and it's still brown/grey. I haven't modified the airbiox lid yet either. I'm certain it's jetting I just need help or some direction. Thanks Guys!

[ohsobad_chevy]

I take it that you adjusted your valve lash to the hotcam's specs right?? If not you need to do that right away. When you say you dropped the needle one position, do you mean move the clip up or down??

[400exstud]

If you are running only those mods I suggest that you run somewhere close to a 152K main jet and needle in the stock position.

My friend has that and it rips!

[ohsobad_chevy]

All depends on elevation and temperature as well. Your jetting is never going to be perfect all the time.

[400exstud]

That is true but this will get him very close. I am trying to point him the right direction. As it sounds he needs it:) .

One thing that you need to know is that the needle steps are VERY large. You could easily run a full system and a cam and never need to touch the needle.

[ohsobad_chevy]

I put a HMF full system and a UNI filter on my quad and I had to go to a 152 main, 42 pilot, and then I ended up moving the clip to the 2nd pos from the bottom.

[quadman21]

Thanks for all your help so far. When I said I dropped the needle I meant that I lowered the clip one position which should actualy raise the needle itself, correct? My elevation is about 2500 feet. I bought a 180, 182, and 185 main to play with today and the 180 just made it worse. Right now I have the stock exhaust but my HMF should be here any day. (I know I should have waited for HMF...lol) Valve lash? I'm not sure what you mean. Are you talking clearance? As far as timing I think I got it right. Let me ask one thing. The mark on the flywheel, it would be the last "grooved line" towards the rear wheels? Cause my flywheel had a small white painted line that mathced up when the dot on the flywheel lined up with the arrow on the case.

[400exstud]

I am just trying to save you some frustration.

You will need to buy a 150K, 152K, and 155K. I would bet ANYTHING that your setup will fall into this range until you put the HMF on.

PS: A 180K is meant for a 440ex or 465ex that are fully modded out. Rarely ever to you see someone using such a big jet.

Don't be afraid of running lean. When I first started jetting, I was very fearfull of this. Now I have my bit jetted a tad lean, just as a personal preference and it is very reliable.

[GPracer2500]

Originally posted by quadman21
...The mark on the flywheel, it would be the last "grooved line" towards the rear wheels? Cause my flywheel had a small white painted line that mathced up when the dot on the flywheel lined up with the arrow on the case...

I can't make any sense of that. Do you have a service manual? If so, read it again. If not, get one.

If you just installed a cam and an airfilter an made no other changes, than your engine should not "...just [feel] dead. Not a lot of power..." Even if the changes caused your jetting to go a little lean (likely) than it shouldn't be enough to cause a big change like you're describing. I suspect your cam timing is off or there is some other issue. If you're one tooth off on the cam timing than the engine will run fine--it'll just be real flat. Kinda sounds like what you're describing.

Put your jetting back to what it was when you started and make sure your cam is installed correctly. Once you're sure there is no issue with the cam install, then start changing your intake/exhaust/jetting.

BTW, valve lash = valve clearence.
Moving the clip down raises the needle up which is richer. Moving the clip up moves the needle down which is leaner.

And which cam is it?

Once the cam is sorted: If you're trying to jet by the plug than you'll need to use fresh plugs and do throttle chops. A plug that you've been riding around on at all different throttle postions won't tell you squat.

[GPracer2500]

Originally posted by 400exstud
I am just trying to save you some frustration.

You will need to buy a 150K, 152K, and 155K. I would bet ANYTHING that your setup will fall into this range until you put the HMF on.

PS: A 180K is meant for a 440ex or 465ex that are fully modded out. Rarely ever to you see someone using such a big jet.

Don't be afraid of running lean. When I first started jetting, I was very fearfull of this. Now I have my bit jetted a tad lean, just as a personal preference and it is very reliable.

I'm with ya on all that. Although in the temps I often ride in, I usually go the other way--a tad on rich vs. lean side. Like you said, there is a little bit of personal preference when it comes to the finer points of jetting.

[quadman21]

I haven't got the service manual yet but it's next on the list. I used the instructions off the Hotcams website. (By the way It's a Hotcams Stage 1 cam.) I just felt it would not be too complicated. I've always owned Honda's, my 400EX was pretty modified, and I've alway's done my own engine work.
The cam thing is the likely candidate. I'll double check that tonight. I know I was a little unclear about trying to describe the whole timing thing. All I was trying to describe was lining up all the marks for TDC when doing the timing. Just to be on the safe side can one of you guys list what has to be lined up? That way I can make sure when I tear into tonoght. Thanks again guys for the help. I know the whole jetting issue gets old after awhile. Oh ya, I got the 180 main jet idea from the HMF website.

[GPracer2500]

Wait--what quad are we talking about? Somehow I was assuming a 400EX?

Whatever the case, everything I said still applies.

[quadman21]

LOL, sorry. I'm talking about an 05 450R

[quadman21]

Alright. I re-inspected my istallation and found I was a tooth or two off. (long story) So now that it doesn't feel really flat anymore it has a tremendous bog about mid throttle. I even went back to stock needle position and stock air filter. I guess I'll just wait until my HMF comes next week, put the UNI back on and try it again. Then maybe the 180 size jets will work. Thanks again for your help. However, with just installing a stage 1 cam should I be experiencing this bogging problem?

[400exstud]

Originally posted by GPracer2500
Wait--what quad are we talking about? Somehow I was assuming a 400EX?

Whatever the case, everything I said still applies.

I'll second that. My bad:ermm:

[GPracer2500]

Originally posted by quadman21
Alright. I re-inspected my istallation and found I was a tooth or two off. (long story) So now that it doesn't feel really flat anymore it has a tremendous bog about mid throttle. I even went back to stock needle position and stock air filter. I guess I'll just wait until my HMF comes next week, put the UNI back on and try it again. Then maybe the 180 size jets will work. Thanks again for your help. However, with just installing a stage 1 cam should I be experiencing this bogging problem?

Cool. Glad you got the cam figured out.

Changing the cam often will require a small jetting change. I'd be a little surprised if the addition of a stage 1 cam caused a "tremendous bog" though--especially at mid throttle. But I don't have any direct experience with that so I couldn't say for sure.

I'll mull it over and report back if something comes to mind. A detailed description of the bog and when it occurs would help.

There's probably some folks in the 450r section that could help with 05' baseline jetting with your mods.

[quadman21]

Thanks