2011 Crossfire 800 WOT Bog

[tyman212]

Got a 2011 crossfire 800 with about 2200 km on it. If I'm at close to an idle and wack the throttle it bogs out terribly like it drops to one cylinder almost. And won't rev up just sputters the whole time. So have to let off below quarter throttle and ease into it and then it will rev up fine. If I'm at a stop and roll on the throttle it revs up good and seems to have full power. Or if I'm above a quarter throttle and pin it then it normally doesn't bog either. Makes it really hard to ride when it bogs this bad. Never had this problem before. Started when I was coming down the trail in the mountains and haven't figured it out yet. Sleds stock with a MBRP can and Bikeman Y-pipe. Ive had it in the shop to completly dry out. Checked the pressure sensor hose on ecu. Replaced the exhaust sensor. Replace the spark plugs and one wire that seemed to be wore pretty badly. Adjusted exhaust valves and they seem to move freely. Compression test is 135 psi both sides. Also ran so fuel treatment cleaner stuff through. Was wondering if maybe the reeds were bad but that should have showed up on the compression test. Could it possibly be a bad TPS? Not reading correctly anymore. Anything else anyone think it is?

 

[sleded1]

Check your reeds, seems like the same thing I had happen, same year, same sled.

 

[tyman212]

I'll check those out and see what I find. Thanks

 

[Doof]

It wouldn't hurt to check your reeds, but I don't think that's what it will be. I'm on my 3rd set of reeds on my 2011 M8 and I've never I had a WOT bog when the reeds were toast, it would only load up on the bottom end and then once it opened up it was good to go! I would take a look at your clutching. I know when the inside spider on my primary cracked a couple years ago all I had was a WOT bog until I looked at the clutch closely and seen what the problem was.


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[tyman212]

But it will only big when i hit the throttle fast. If I ease into it then it revs up fine. The primary was replaced last year due to a sticking roller so it only has maybe 500 km on it. But I'll inspect that too when I have it in the shop.

 

[Doof]

Ya check it to be sure, doesn't hurt to inspect clutches before every ride. We're actually having the same problem on my dad's 2010 M8 now, just replaced his primary 2 weeks ago as well. We have the weekend off to try and figure it out, so I'll let you know if we find anything.


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[tyman212]

Pulled everything apart. Primary looks good as far as I can see didn't notice any cracks or wear marks. Rollers are all smooth and the weights move freely. Reeds are a little chipped on the top center two pedals. Will replace those just because I have them out but they wouldn't need to be I don't think. Noticed my Y-pipe has a very small crack where the two sides come together on the back side. So I will be putting the stock y-pipe back on see if that changes anything. Doesn't appear to have been leaking much as there is very little black residue sprayed on my motor. But maybe that was causing my exhaust sensor to read incorrectly. Pistons look very good, looking into the exhaust ports. Exhaust valves move freely however one cable feels a little stiffer than the other. But I'd be surprised if that's causing this.

 

[Doof]

Reeds are cracked open at WOT anyways so fixing those chips might make a small difference on the bottom end (from my experience anyways). We phoned a couple dealerships around Edmonton and they think it could possibly be the fuel pump starting to go? Which makes no sense if you can still get the sled to full RPM's. We pulled the exhaust valves, cleaned and adjusted, sled is still bogging. We think the fuel might be bad since it hasn't even burned a full tank yet this year, we're going to dump some octane boost in it today. If that doesn't work we'll empty out the fuel and check the fuel pump.


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[tyman212]

Yeah I was thinking fuel in my sled when it first started so I drained it and added fresh which didn't help at all. Yeah chipped reeds normally only affect the throttle response at bottom end. Don't expect then to change wide open. Talked to the dealer in Camrose where I used to work he said it's most likely the throttle position sensor. So if it doesn't run any better after i put it all back together I'm going to take it in so they can put the computer on it and check the tps. I don't really see how the fuel pump would cause that sort of bog. If the fuel pump was bad you would think it would bog after holding it wide open for a little bit. Not when ur just getting on it.

 

[tchriste]

When the fuel pump/regulator go the fuel pressure goes too high and loads up the machine at idle and bottom end. I would check fuel pressure and see if the pressure is out of spec (42-47 PSIG) One can just replace the regulator with one from BDX, Cat wants to replace pump and reg.

 

[tyman212]

Little update on my sled In case anyone is interested. Got it all back together. Welded the y-pipe, new reeds, still bogging so I took it to the dealer. They checked the tps, fuel pressure, all was good. Said the wire on the exhaust sensor was broken, so they fixed that. I took it home went for a ride and it seems to be bogging worse now then it has been. So I just dropped it off at the dealer again to actually fix it this time.

 

[Doof]

When the fuel pump/regulator go the fuel pressure goes too high and loads up the machine at idle and bottom end. I would check fuel pressure and see if the pressure is out of spec (42-47 PSIG) One can just replace the regulator with one from BDX, Cat wants to replace pump and reg.

How do you go about checking the fuel pressure? Install a small t-fitting with a gauge onto the fuel hose coming out beside the coolant tank? Still having problems and thinking this may be the problem.

Also, tyman, let us know what they actually fix this time around and whether it solves the problem or not. Thanks

 

[tyman212]

Yes that would be the easiest way to test fuel pressure. I didn't have a guage and right size of fittings so I let the dealer do it, just got a call saying the fuel pressure on my sled was 80 psi at idle so that has to be the culprit. Not sure how it checked out good last week when they checked it, but it should solve the bog I'm having.

 

[Doof]

That's a tad on the high side I'd say. So what did they say the issue was, regulator needs to be replaced?

 

[tyman212]

Just a little above spec. Haha. These sleds don't have a seperate regulator, it's part of the pump. As far as I know. So with it being warrenty I'll be getting a new pump.

 

[Doof]

Haha just a little! Well that's good to know that's what is causing the problem, looks like we're testing fuel pressure one of these days!

 

[Doof]

Just did a pressure test a couple hours ago and got 47psi of fuel pressure! Like what the fudge!


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[tyman212]

I'd try test it again. Not sure what the deal is. But mine tested fine once but then the second time it was way to high. So maybe it's more intermitted even tho it bogs out all the time. Doesn't really make sense tho.

 

[Doof]

Ya I'll test it again a couple times again today and see. Going to try adjusting the throttle cable and unhooking the TSS and see what happens, if that doesn't work I'll post a video of what it's doing.


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[Doof]

So I took a quick video of it and it's still spitting and sputtering at WOT (sound isn't the greatest). Engine was fully warmed up at the time. Adjusted throttle cable as it was a bit tight but didn't do anything. Tested fuel pressure before and after the video, both times 47psi. When it's at full throttle it's only hitting 7600rpm. New boyesen reeds, new primary with arctic cat gold spring, changed plugs, fresh gas in. Anybody know what's going on???