I have a bog that happens right around 7500 rpm. It however does not happen all the time. I have put a new fuel filter in it, new power valve Springs, cleaned the power valves, adjusted the throttle cable play. It had a broken power valve spring so I thought that was the issue but nope. We have plugged the emission hoses on the power valves and left the solenoid alone . Sometimes the bog occurs at slamming the throttle open, sometimes it accelerates just fine. If it does bog most often feathering the throttle gets it past the big and it just rips. It is a 2009 600 efi rmk shift 155. I have bought new 64 grams weights but have not tried that yet. We were thinking it maybe the TPS but it does not throw a code at all nor does the light flash even. The power status bar on the dash shows full charging all the time. Does anyone have any other ideas? Like I said it is Intermittent sometimes it will run for several.minutes without a big issue at all. Other times it bogs several times in a row. If you feather through it and it clears up then it seems most times tof be alright for a bit. This is driving me nuts. I wish it had carbs right now.
Intermittent bog.
- Thread starter tryanattak
- Start date
Well I installed the 64 gram weights in the primary. It did not make it any better if anything it got worse. We tried unplugging the O2 sensor and it made it more sluggish when blipping throttle but did not flash the engine light at all. We basically did this to check if the engine light would flash as it does not do it like my son's 05 RMK would. He had a TPS issue and his flashed the light. Would a fuel commander over ride the TPS. I forgot to mention the sled does have a MRBP can on it. Is it possible that could be making the bog issue? I am not sure if the previous owner had any issues but the can was on it when I got it. As I have stated it does not bog all the time, sometimes you hit the throttle and it rips right away other times it hits a dead spot then goes. My readout shows I have hit 8300 rpm as a max. The bog seems to happen right at 6750 now thinking that could be the new 64 gram weights it had the 58 gram weights from the factory in it. Any help would be appreciated, thanks.
I had an assult 800 cutting out at 7000 ,the cause was a torn bellow in the power valve . I got segestions like clean the power valves and run a wire up in the cylinder to make sure the port is clear and same for the valve it's self.
V
volcano buster
Well-known member
I've got a '10 660 that bogs at WOT after a while. I was out Thursday and was running WOT in about 2' of fluff on the road. It would start to cut out like I was losing fuel pressure to at least a couple of the injectors (4 total). Let out, back into it a couple times and it would hammer back up to max R's.
I plan to pull the fuel pickup out of the tank and see if there is anything funny going on in there.
I plan to pull the fuel pickup out of the tank and see if there is anything funny going on in there.
We did all the suggested fixes. We cleaned the valves, put new bellows and valve springs in it. We adjusted the throttle cable play to spec, we ran a stiff piece of wire through the purge hole, we replaced the fuel filter, put 64 gram weights in the primary clutch. It still has the intermittent bog issue. It now happens at 6500-6750 rpm range. Above and below that their is no issue. Sometimes it just rips right on through that area and other and most times it hesitates or bogs in the mentioned range.
I have been researching this like crazy and I think my answer may be the lazy power valve issue. The purge hole needs to be enlarged and go back to the lighter weight power valve springs. I even tried a dyne jet fuel commander, it helped in the problem rpm range greatly but messed up the bottom end. I will eventually pull the head and drill out the purge hole to the bigger size and see if tha indeed fixes it.
I have been researching this like crazy and I think my answer may be the lazy power valve issue. The purge hole needs to be enlarged and go back to the lighter weight power valve springs. I even tried a dyne jet fuel commander, it helped in the problem rpm range greatly but messed up the bottom end. I will eventually pull the head and drill out the purge hole to the bigger size and see if tha indeed fixes it.
V
volcano buster
Well-known member
4 injector motor?
Probably 2010 or older cfi like a dragon ?
No the 2009 RMK shift 155 is the CFI2 engine. We just today pulled it apart again and found the spring on the mag side was broken again. I just replaced the springs last season and only have put maybe 200 miles on those springs. I cleaned everything again, ran a wire through all the purge holes, and installed new springs again. It seems better but still happens.
I've read through both threads you have going on this problem. Have you taken both clutches apart and checked for wear and or binding in either the primary or secondary? How are the spider button to tower clearances? Spec is for .002".
Shake the exhaust can and see if there are any loose pieces in there, broken baffles could cause this as well. I have chased an intermittent bog on my Dragon for some time. But now I have a crank out.
Someone tried to tell me that if the crankshaft is out of phase it will do this. Not sure how that would be an intermittent issue and not continuous but I guess I will find out when I get a new crank put in. I'm also going to replace motor mounts to be sure (since I am not getting full RPM in spring riding conditions), although seat of the pants feel tells me it is fuel or spark related... changed out stator, ignition coils, fuel injectors with harness, TPS, etc. etc.
I rigged up a test harness so I could test the resistance of the TPS over the full range of throttle positions with an analog meter to make sure there was no glitch or dead spot. I am still leaning towards TPS myself, we'll see when I get the sled back together if the crank was the issue and if not I think I will replace the TPS with a new one just to be sure it is good.
Someone tried to tell me that if the crankshaft is out of phase it will do this. Not sure how that would be an intermittent issue and not continuous but I guess I will find out when I get a new crank put in. I'm also going to replace motor mounts to be sure (since I am not getting full RPM in spring riding conditions), although seat of the pants feel tells me it is fuel or spark related... changed out stator, ignition coils, fuel injectors with harness, TPS, etc. etc.
I rigged up a test harness so I could test the resistance of the TPS over the full range of throttle positions with an analog meter to make sure there was no glitch or dead spot. I am still leaning towards TPS myself, we'll see when I get the sled back together if the crank was the issue and if not I think I will replace the TPS with a new one just to be sure it is good.
I have to be honest, we have done nothing with the secondary yet. The primary everything looks good and the sled only has about 2,000 miles on it. I guess when I take the head off to drill out the purge holes I can pull the secondary off and tear it down then. I really am leaning to the purge holes being to small. It has an MBRP can on it and I am not sure if it was reflashed for that or if a reflash is even needed with that can. Thanks for your response it is greatly appreciated.
