08 Brute Force 750I, running bad

[Joe T]

I've got some good advice so far but before I take it in I'd like to know what they are going to look at. Also I would mainly like to know if anything like this has happened to anyone else?

I can go crank it up if it sits awhile and it runs ok for like 20 seconds. Then it runs bad and starts missing hard. Black smoke out the rear, really rich etc. Dies unless I keep in the throttle and make it run.


I've checked the plug wires so far and they are plugged in ok.




Thanks,
Joe

[Bwild]

Kinda sounds like tps sensor

[Joe T]

We'll see. It's in the shop.


The first thing he pointed out was that my airbox looked like water had gotten into it so I had him pull everything apart in front of me so that i could show him that the intakes and everything under the filter was squeeky clean.


What a crappy design that it'll let water splash up in there like that.

He told me to snorkle it and I hope somehow they don't pull some BS on me because it's never been in water that deep.

[Bwild]

Yeah the air box designes are terrible, post what they find out. You really have to keep a close eye on the air filter

[Joe T]

Will do. My saving grace I hope is that it was obviously spotless clean beyond the filter.

The housing wasn't too bad really but you could tell water splashed in there but not too much.


He revved the motor open to see if there was any water in there. I've heard it'll kick it back out of the throttle bodies if it gets in there.


They are going to do a compression test on it first. I asked if it could be electrical and he kinda laughed and said it could possibly be.


Also I noticed it was puffing a little blue smoke in the gobs of black smoke that was coming out when he drove it in... But maybe I'm just seeing things.

[Joe T]

Oh yeah. Another thing. It has pretty much always since new backfired out of the intake pretty bad hot or cold... Enough to scare me .

It also seems to not pull wheelies like when it was new.


Right now it only has about 25 hours on it.

[Bwild]

Did you check your oil? Being a V-twin a spark plug can fail causing unburnt fuel to enter crankcase thinning out your oil which will enter your firing cyl past the rings causing the smoke. did you try changing your plugs. seen this happen lots

[Joe T]

Originally posted by Bwild
Did you check your oil? Being a V-twin a spark plug can fail causing unburnt fuel to enter crankcase thinning out your oil which will enter your firing cyl past the rings causing the smoke. did you try changing your plugs. seen this happen lots

Yeah it's full but I had just changed it less than an hour ago.

[Bwild]

Was the old oil pretty thin?

[Joe T]

Can't remember. It didn't have an obvious odor of gas though.