Major bog.....sometimes

[edge_kw]

'04 Warrior. Starts, idles and runs great.....most of the time.
But occasionally, after being into the throttle heavy and letting off quick, the sled BOGS BADLY when trying to get back into the throttle. You have to feather it for about 5-10 seconds and then it clears up.
Kind of acts like its flooding out. Sometimes it's accompanied with a backfire on slowdown.
The problem was very intermittent to start with, but seems to be increasing.

Any ideas on what to start looking at?
Thanks.

 

[RedRocket]

First thing I would do is pull the plugs and look at them. You can tell a lot about how the engine is running by the color of the plugs. How old are the plugs anyways? If they are a nice light brown color and all the same (which is more important) then I would check the enricher cable (aka choke) and make sure it is not sticking.

If that doesn't solve it, check the TPS (throttle position sensor). Here are the pages out of the manual on how to check and adjust the TPS.

 

[edge_kw]

I thought possibly plugs too. Swapped them out (all looked good after 4000 miles!!) and cleaned the coils. Same thing still happening.
Shouldn't be the choke.....it doesn't get applied after startup and if it was stuck, I suspect it would cause bog continuously.

Thanks for the info on the TPS. I'll check that out.

 

[fryguy]

I had the same thing happen on my 05 RX-1. Turned out that the locking nut on the throttle cable had come loose and the TORS switch on the carbs was being affected. I bypassed the carb TORS switch (yes I know dangerous, but I put it back after I tested it) and the problems went right away. Adjusted the throttle cable back to specs, tightened the locking nut, hooked TORS back up, and problem solved.

 

[edge_kw]

Thanks for the response fryguy, but I've tried disconnecting the TORS and had the same issues disconnected and connected. So it's not that.

 

[kinger]

Does it ever backfire after a long WOT pull on teh decel? Maybe bad exhaust donut gaskets, they usually dont cause a bog though.

 

[edge_kw]

Kinger - Yes. "Sometimes it's accompanied with a backfire on slowdown."

 

[kinger]

I would definitly be interested in the exhaust donuts then unfortunatly they are a lot of work to check.

 

[Skydog]

Make sure air box is on all the way.

Skydog

 

[VT_BluYamaha54]

What has been done to the carbs? Are they 100% stock? Are they "hospital clean"??

 

[edge_kw]

Carbs are 100% stock.
"Hospital clean" ?? - going to go back through them this weekend.

 

[Skydog]

Make sure air box is on all the way.

Skydog

 

[Len Todd]

The intermittency of the problem has me wondering about fuel quality and something electrical. Something is variable.

Clogged carbs typically would not be variable. Occasional shot of bad fuel would be variable. Of course you may have to go after the carbs as well as the whole fuel system, if you got junk in the fuel?

I am sure by now you have validated all the air connections to and from the carbs and verified air-box integrity.

Also, the backfire seems like a second issue, if you have positively ruled out TORS. If it was TORS, you could explain both issues being due to one fault. But ruling out TORS does not rule out a different electrical problem.

Also, you cleaned the coils. I suspect that you removed the rubber rings and validated that there was no lightshow.

It just sounds electrical. An electrical problem would give you the backfire and lack of power. Are there any loose or poorly connecting wires (e.g. coil connection, grounds, fuses in the holders, harness connectors, CDI connector, etc.)? If there is a lot of oil inside the engine compartment, some contact cleaner on the connectors often works wonders. How about wires that may have rubbed into the frame/chassis causing an intermittent short? This was a generic issue with earlier RXes.

 

[edge_kw]

Well, I went through the carbs this weekend. I doubt it's carb related, because they were real clean, but it was worth checking.
I checked the TPS and it's reading where it should be.
I went through all the electrical connection I could get my hands on and also checked for any wire chafing.

So, if it ever snows again (other than this "almost rain" stuff we have falling for the last few days), I'll report back if the issue is still present.
Thanks for everyone's input.

Len - I agree w/ you. I've been thinking electrical as well, but being intermittent, it's awfully hard to find.

 

[bluehammer]

Could be clutching. Tighten the secondary 10 degrees for starters. The spring may be going away on you causing you to suck the belt. Stock helix? Worn belt? It sounds as if it's not backshifting, thus loading the motor.