99 700 low & mid rough running

[Timber700RMK]

Total rebuilt engine. SLP crank job Pol pistons VF3 reeds SLP pipe/can, airbox mod, powerpacks. Took it out after going through everything It starts & idles wonderful. It has what seems to be a miss or sputter from low to mid range up to about 6K. After 6500 it wants to fly Takes off like a rocket. When crusing at 5-6K it seems like it is missing. Took off the carbs & cleaned them twice thinking a clogged pilot jet but didnt change anything. Pinning it from a idle it stutters then kicks in. Need all your suggestions.

 

[MARV1]

What is your jetting at? Clutching? How old are your springs?

 

[Timber700RMK]

Jetting is per SLP spec on the mains 205 for pipe & air box mod. Clutch & all components are brand new with black / red SLP spring 62g weights per SLP New SLP helix. It doesn't feel like clutching. It doesn't bog, it sounds & feels like it is missing intermittenly (sp) untill it gets over 6K then it screams

 

[Timber700RMK]

Any ideas from you master mechanics?

 

[Lake Cle Elum]

Float level is critical on a '99.....If it's too high, sled will act this way...

 

[AndrettiDog]

Deju vu...

I had a '99 RMK 700 and rebuilt the top end after I lost the crummy pump belt. Anyway, I pulled the carbs off and checked them inside and out. I kept getting the same thing. Sled would bog and run like crud until it got going. Then it took off and ran great. I finally pulled the carbs again and there was a small piece of debris in one carb stopping the needle. Pulled it out and the sled ran awesome. By the way...I never did any adjustment to the carbs. Make sure they are clean before you start adjusting everything.

 

[the 2x4]

Ya just check and make sure that there is nothing in the float bowls. Sometimes dirt gets in there and fouls things up. Clean the piolet circut out and you should be fine. could be too lean at the bottom end at the low elevation. weights might be an issue too.

 

[FEZ]

Ya just check and make sure that there is nothing in the float bowls. Sometimes dirt gets in there and fouls things up. Clean the piolet circut out and you should be fine. could be too lean at the bottom end at the low elevation. weights might be an issue too.

Is it a lean bog or fuel bog? Tap the choke then squeeze it, if it gets better than you have a lean bog.

1)As i was cleaning my 00' 700 carbs i noticed some red stuff coming out of the bowls. It turns out the water traps were deteriorating and pieces of rubber were getting into my needles. Last season it ran very erratically, much like you stated, i would clean the carbs and it would run good, but I always pull the needles ona cleaning. Check/replace the hoses on the bottom of the carbs.

2) Buy a set of 1371G needles and put them in the 4th from top slot and get some 38 pilots unless SLP says otherwise but i think they just change the mains on the singles.

 

[ivar]

Also check the float bowl pins, on my 99, the holes were worn, causing the floats to bind intermittently and cause inconsistent running.

If it had misfired also at other rpms, I'd think it could be something electrical, e.g throttle switches acting up etc.

 

[Timber700RMK]

Thanks! I got the 1371G needles & 48 pilot's per SLP recommendation. The carbs have been off & CLEANED ALL SUMMER & I went through every nook & cranny on them. I will check the float hieght. SLP said to raise the needle clip 1 position (lower e-clip) Neighbor says to put the needle back to 3rd position & see if that clears it up. Feels like a fuel issue. Choke kills it so I don't think it's too lean. I will go through the carbs again, check float height & drop the needle 1 step & try it out.
Thanks for the help

 

[concritter96]

Does your sled have reeds behind carbs? I have an o3 700 w/same problem. Went through every thing carbs,plugs, wires, checked compression couldnt find anything. finally pulled the reeds out and they were gone. dont know if thats a common problem or not.