850 Bad Bog

[2012ProRMK]

Have a 2017 850 with 150 miles that I just purchased.
It idles good, maybe a little choppier than my 800 etec though.

Just went out for a burn up the ditch. It has a really bad bog right from basically no power to wide open. Won’t pass 7000 rpm. Almost feels like it’s on one cylinder in terms of power.

Took plugs out, both were wet with gas. Could this be my problem? Am a couple hours away from new plugs so would like to make sure.

If it is, any ideas on the root cause? It still has like 50% break in left. Not sure if fogging it the previous spring can cause any issues like this.

Thanks

 

[firstdoo]

I would start with a compression check. You already had the plugs out. When you put the plugs back in you need to make sure they are indexed. Use a sharpie to mark the porcelain to help. But a bad bog sounds like it could be a piston issue.

 

[Big A]

The fogging could have fouled the plugs but pretty good chance it’s a mag side piston due to injector failure. A compression test will tell the tale. I’ve been there, call your local dealer with the VIN and see if the updates got done on that one, some wiring harness updates and re-routing for that injector, if they didn’t get done yet, really good chance that’s the problem. Sorry to bear bad news.

 

[catrutt]

Does the injector quit and then the engine burns down ? What is the problem with the wiring?

 

[tko sled ed]

Seems to newfor this but mine was fuel pump

 

[kanedog]

Drain fuel tank. Fill with fresh 94.

 

[drew562]

Is it pulling good at any rpm? The doo will sense over rev and cut out long before 8000 rpm with mountain clutching and low elevation.

 

[Big A]

Does the injector quit and then the engine burns down ? What is the problem with the wiring?

Two things can happen, It can rub through in the one spot, or it can come disconnected at the injector itself, either way the injector fails intermittently, creating a lean condition and burning up a piston. BRP has had a warranty campaign on this since back when the first major round of updates were being done back in the spring and fall of ‘17

 

[ferniesnow]

Have a 2017 850 with 150 miles that I just purchased.
It idles good, maybe a little choppier than my 800 etec though.

Just went out for a burn up the ditch. It has a really bad bog right from basically no power to wide open. Won’t pass 7000 rpm. Almost feels like it’s on one cylinder in terms of power.

Took plugs out, both were wet with gas. Could this be my problem? Am a couple hours away from new plugs so would like to make sure.

If it is, any ideas on the root cause? It still has like 50% break in left. Not sure if fogging it the previous spring can cause any issues like this.

Thanks

Take it into the dealer so they can but the BUDS on it. Whatever it is, it will come up right away.

The chaffing of a wiring harness was one of the recalls/fixes on the '17's.

 

[Wapow]

Ha! So much doom and gloom! If it was running well for the seller before they put it away for the summer, then it isn't a wire chaffing. Fresh gas would be a good start. If that doesn't work, take it to the dealer. Bogging and wire chaffing are not common problems on G4s, even the '17s (I have one and have been paying attention to these forums since I bought it).

 

[ferniesnow]

Ha! So much doom and gloom! If it was running well for the seller before they put it away for the summer, then it isn't a wire chaffing. Fresh gas would be a good start. If that doesn't work, take it to the dealer. Bogging and wire chaffing are not common problems on G4s, even the '17s (I have one and have been paying attention to these forums since I bought it).

I was speaking from experience and offered a solid solution. If wire chaffing wasn't a common problem, why did they have a service bulletin and new parts to fix a known problem. We had 2 '17s, an '18, and now a '19, so I am also familiar with the goings-on. Fresh gas, as well as, a good run to clean out the "summer fog" were mentioned above and there was no reply from the OP as to whether it was done.