loose blown powervalve base gaskets, could this be part of the bog problem???

[gman086]

Yes this would be a definate issue. They work on exhaust pressure not vacuum but same idea. Pressure must build up behind the bellows to overcome the spring and then the valves open. If you have a gasket leak, no pressure build up = no valve opening. Voila!

Not exactly, the point at which they open are controlled via vacuum from the ECM controlled solenoid. You can (and even SHOULD) convert them to gas powered by blocking off the vacuum lines. Then they run soley on exhaust pressure and open sooner. Gas mileage will suffer but you'll have power sooner and less heat soak (better for us mtn riders; flatlanders are best served by staying stock). The gasket IS still critical for vacuum operation as it needs to be sealed!

Have FUN!

G MAN

 

[m8sandman]

yes it is the #2 gasket that is blown on mine. will be riding with my dealer this weekend so hopefully the new injectors or the new powervalve base gaskets will be the vaccine i need to cure the bog got my fingers crossed!!! will make sure to check the bellows when i have it apart... will post up when i get back and let you all know how it went!!!

 

[m8sandman]

ok, so tore it down completely yesterday. the left side powervalve is located directley behind the steering post so will not come straight out. i went ahead and unbolted the steering post and was able to move it far enough forward to allow me to remove the powervalve after takeing the plastic cap off. was wondering how much torque is on the number 6 bolt??? hit it with a wrench while it was in the head but didn't want to put much force on it and put a gouge in the head.

also when doing the injectors would suggest removing the clutch cover, this will give you easier axcess to the left injector. i left the oil bottle hooked up and unbolted the ecm from the cover and left it hooked up also. left the two rectifier looking boxes on the cover and just unplugged them. there is a double set of orings on the engine side of the injectors, the new ones only come with the large orings on the injectors. the other oring is a thinner one on the engine side of the injector which seats in the opening for the injector itself. make sure to coat the orings with oil or some type of lube as they are a tight fit and you don't want to shave off a side of the oring when installing them!

this is where i unbolted the steering, you'll also notice all exposed wiring taped and secured, coil mounting bolts flipped.

what the gasket looked like after it was removed, you can see it split right where the pressure port for the bellows is.

this is what to look for when installed, the oil is the first give away, mine had spit the gasket nearly all the way out!!!

so if your sled has the same symptoms as mine this would be a good place to start to look, sure between this and the new injectors my bog should be fixed. will find out tommorow and let you guys know!!!

 

[m8sandman]

I'M CURED!!!! went out today and even rode in the rain to see what was gonna happen, 8250-8300 on wet pack, NO BOG!!! now all we need is it to snow instead of rain

 

[greasemonkey3406]

Glad to hear its workin for ya.

 

[AKSNOWRIDER]

you gave it to mine...bwahahaha..rode up high today...3500 ft up to 6000 ft..put in 64 gram belly busters just to try...bad midrange bog at aprox 6000 rpm every time you hit the gas..once i climbed some in elevation...magicallygone..ran perfect..till i got back down in elevation...i suspect a lot of the mid range bog is due to not enough clutch load...mine was super snappy right up till it bogged...odd though..couldnt see the tach reading over 73-7500 rpm at any time that it bogged..but the ecu is somehow seeing the low load in the midrange....(oh..it was -30 f. when i left the truck...-60 f. when i hit my buddies cabin 45 miles in....)dang sleds are super crisp at that cold....

 

[Norway]

midrange bog at aprox 6000 rpm every time you hit the gas..once i climbed some in elevation...magicallygone..ran perfect..till i got back down in elevation..

So, what changes between altitudes? Air pressure = ecu and mapping..

From what you describe this sounds like a mapping thing, and mapping is affected by TPS so this could be a situation where a lean spot in the mapping is thrown over the edge by a slightly "faulty" TPS setting??

Comments please.

Edit: does the ECU know anything about what the powervalves are doing? Open/closed?

RS

 

[Rick!]

you gave it to mine...bwahahaha..rode up high today...3500 ft up to 6000 ft..put in 64 gram belly busters just to try...bad midrange bog at aprox 6000 rpm every time you hit the gas..once i climbed some in elevation...magicallygone..ran perfect..till i got back down in elevation...i suspect a lot of the mid range bog is due to not enough clutch load...mine was super snappy right up till it bogged...odd though..couldnt see the tach reading over 73-7500 rpm at any time that it bogged..but the ecu is somehow seeing the low load in the midrange....(oh..it was -30 f. when i left the truck...-60 f. when i hit my buddies cabin 45 miles in....)dang sleds are super crisp at that cold....

These things seem really sensitive to variances away from the stock clutching. There's some room at engagement and WOT for mods but my experience is that midrange doesn't like to be fiddled with. The overrev thing is a bit annoying also. I'm sure there's more than one way to skin a cat, though.

 

[AKSNOWRIDER]

So, what changes between altitudes? Air pressure = ecu and mapping..

From what you describe this sounds like a mapping thing, and mapping is affected by TPS so this could be a situation where a lean spot in the mapping is thrown over the edge by a slightly "faulty" TPS setting??

Comments please.

Edit: does the ECU know anything about what the powervalves are doing? Open/closed?

RS

I dont think its mapping per say...the weekend before I rode a totally different clutch setup at the same elevations...was heavily loaded in the midrange and snappy over rev up top....sled never bogged in the midrange with that setup...but I could hit the rev limiter at 1/2 throttle turning 8500 rpms at parking lot elevations...soon as i gained elevation was off the rev limiter unless I unloaded the track on a climb....what it was doing this weekend was different...more like what I hear many on here complain about..would love to see a few of those with a bog issue try throwing a heavier set of weights in just to see if it cures the issues...., but norway is right..this electronics package is very sensitive to clutching changes and how the sled runs...

 

[m8sandman]

you gave it to mine...bwahahaha..


sounds like poo needs to get some sort of shot out there to get peeps immunized

maybe try and put your clutching back and see if the bog is still there. have been thrown more than once doing a change and then having a problem thinking it must have been what i changed and it ended up the actuall problem just happened to start about the same time. at least this way you have a good base line to start from.