Off Idle bogging.

B

BlueIronRanger

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Nov 26, 2003
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I took my sled out for a rip after putting on a ripsaw, thin head gasket, and reed stopper notch. The Midrange "burble" is now gone but I get a decent off idle bog if I nail the throttle to the bars from a dead stop which it did stock but its worse now. When the throttle is pinned it hesitates for about 1/2 second before it jumps into motion (once it gets going it pull WAY better than stock). Is this off Idle bog a function of the Neddle jet or the Idle screw? Just wondering where to start. Also I just cleaned the jets out so none of them are plugged. If Nail the throttle while moving 20-30mph I don't get the bog and it just gets up and goes.
 
its sounds like a carb problem...clean the carbs and the pilots...check your fuel screw make sure all of them are the same....and as long as you are in there, set the fuel levels. My Rx was acting similar to that yesterday, clean the crabs and set everything I stated and she flys ;)!
 
Might want to move your needle down slightly (shim), ...also can shim your engagement (max. 3shims).
 
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engagement is good, hits right at 4200rpm. I'm going to check and make sure the idle screws are set properly today. The problem has always been there since new, just got ALOT more noticable with the reed notch and thin headgasket.
 
If it ain,t the carbs could be the secondary clutching. If you are running a steep helix & getting good traction you might want to tighten the secondary spring 10 or 20 degrees.
 
Nope....if turning out the fuel screws don,t help you might need larger pilots. Check belt deflection too.
 
well a 52/44 helix is a bit steep off the line and the ripsaw does get good traction. I have a stock red seconday spring @ 80* in there and a Green one on the way along with a 19 tooth upper. I think I'm going to ditch my empty 8ca wieghts too, even with the thin headgasket and notched stoppers it jumps to 8500 off the line (once its past the bog) and comes slowly down to 8300rpm as the MPH climbs. I need to get ahold of some 8ab's I think. The thin headgasket and stopper notch help my gain about 150rpm but I'm still about 100-150rpm of where I need to be with these wieghts.
 
lean bog

Hit the choke right before you nail it. If it is fine doing that then it is a lean bog... Put .9 air jets in.
 
A potpourri of advice, ...make sure you do one thing at a time while testing.
 
I had same thing last year. ended up being lean on bottom end. try turning fuel screws out just a hair. if that doesn't work, try increasing your pilot jet one size then set fuel screws back to 1 1/2 turns out. Are you letting your sled get nice and warm before whacking the throttle? If she's still cold, it'll hiccup everytime off the line. At least for me it does anyways.
 
First do as Turk said and check your belt deflection. If it is too loose (too much deflection), it will be like starting off in a higher gear, and will bog everytime. Also make sure you have a new belt on there (or that the one in there is still well within spec), because a narrow belt will have the same effect. These are the easiest to check, so do them first.
 
I just had to turn my fuel screws out to 1 3/4 to cure this problem after making the same mods to my 700MM. If their clean, that would be what I would try next......
 
I did all the same mods to my SX700R and turned the fuel screw to 2 turns and works fine. You still need to let the machiine get nice a warm before you hammer down on the throttle.
This come right from a Yamaha factory technician who checked my machine.
You really need to let her warm up a good 10 minutes.
 
didn't get to try it yesterday, but might get to it today. It was good and warm as I warmed it up for 5 minutes and put about 6 miles on it hot lapping my 40 acre field. I'm going to try the idle screws first I guess, they are at 2 turns out stock on the 600, I'll give them a 1/4 turn more and test them.
 
got to play with it today, I started off with a green secondary spring since I needed one anyhow but that did nothing about the bog (help the clutching ALOT). Next I pulled the carbs and turn the screws another 1/4 out (2 turns out stock to 2 1/4 out) and it got quite a bit better but its still there (I can't pin it to the bars but I can roll on the throttle pretty fast now). I was wondering if I can go another 1/4 turn out or should I up my pilot jet one size?


I also need to re-attach my snow flap now after doing an unexpected track stand which ripped the snowflap loose! thin gasket, down one tooth 19/39, stopper notch, and ripsaw track made one hell of a difference in low-midrange power on my sled. I was going over a little bump @ about 15mph and pinned the throttle and the front just popped up and scared the living heck out of me, I have NEVER had a sled do that to me.
 
I have an 01 sxr 700 and just installed a set of reed spacers and carbon tech reeds from max perf. They instructed me to go with 142.5 in #1 and 141.3 in #2/3 and run the fuel screw at 1 3/4 out and needle at 2.5. Haven't ridden it yet but fired it up on a stand and it seems like I've got that same off-idle bog if I give it a handful of throttle. I know the carbs are clean as I had them apart and blew everything out. Again, haven't had a chance to ride it on snow, but seems like I've got the same symptoms...any thoughts?
 
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