The infamous powder bog

Bogers unite!!

WIth the snow on the hood and packing the vents closed Im sure that our tripples require HUGE amounts of ox' to run right. Thats why we get the bog and sometimes the sled starts missing like the choke is on.
 
little red bogging in powder

But its only a little 700. I have never had a problem with my SXr 700 bogging like the MSRX . Like I said riding with so much snow on the hood breaking trail melted my hood on the SXr . I would have been a follower if I had my MSRX, never could of broke trail.
 
Well everyone, I went for my first ride of the season this Sunday. About three feet of bottomless floof (need about twice that much to be good), no base, had to be really carefull off the trail or hit stumps, etc. Tons of light snow coming over the hood, even had quite a bit of snow build up on the air box filter and turn to water. Happen to notice this when I opened the hood to set my helmet and goggles underneath to un-ice the goggles. Shook it out a couple of times over the course of the day. Happy to say, not one single sputter all day. ZERO powder bog. I even had my carb warmers turned on, since it was about 15*F and TONS of light snow dust. I've had my flo-rites for about three/four years, but blocking the underside of the dash/hood area with duct tape to keep all underhood air out of the air box has done the trick. I'm running stock plug caps. 80 degrees pre-load on the secondary. I'm going to try to post a couple of pics of the underside of my hood showing what I have taped off.
 
Mine runs great but getting tooo much snow dust on the air box filter.
Plugged all the under hood air now need to find the snow dust leaks.
Its a blast to ride in the powder now with out the bog, just need to
seal out the dust.
 
I have experienced this bog on the 2000 MM700 I got this year. From reading the above posts, the bog seems to be caused by snow getting under the hood and turning to steam when it hits the hot exhaust pipe. The steam displaces air, the air box sucks in steam and air, so the motor runs too rich (not enough oxygen because the air is diluted with H2O). So the post by Mod-it sounds like the answer - block off the air intake from all underhood air. Comments?
 
I just sealed up all my underhood air tonight and did 2 flowrites in the dash. Cured my powder bog completely. 110 % better.
 
Been meaning to do this for a while, sorry it took so long.
Keep in mind, I clean off the outside hood screens quite frequently to keep getting cool air under the hood. Don't want to start melting things by running with snow covering the hood for long lengths of time.

First two are underhood air blocked from entering air box.
viperbogpics004Medium.jpg


viperbogpics003Medium.jpg


Flo-rites mounted in dash.
viperbogpics001Medium.jpg
 
Funny, that last pic looks like my dash is melted in front of the gauge pod. It's not, just ice and some dirt left over from snow that melted after riding in gobs of powder yesterday.
 
Yes, especially when only taking all cold air instead of warm under hood air. I can't really say how much on jetting. My sled was piped and set up by the dealer when I ordered it new. He actually left all jetting stock, as it looked pretty close according to SLP's chart. Rode it 5-6 times, running very rich. I threw in the flo-rites trying to combat powder bog, thinking that snow on the hood was causing under hood temps to go up so much that the sled was going pig rich from the hot air. As we all know, not the total cure. Anyway, this leaned me out to dark brown and I started over-revving about 300 rpm. This was at about 5000'. I left it that way since I ride an area that starts around 2200' on occasion (other than I added weight to outer hole for rpm's). I've since found out that I was still plenty rich and had quite a bit of room. Now with the under hood air blocked so only taking cold air and also running ethanol fuel, my plugs are a very nice cardboard brown.
 
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Mod-It
I got a viper mt. The air induction channels as you said earlier are blocked off from the airbox and do not force any air into the air box. The box is sealed to the hood, yet there is no source for air to the area that is sealed off except for the round vents i have (which were there when i bought it used) and the under hood air that can get through past the headlight etc. Did the round vents come stock when the air induction channels are blocked off? If not, how did expect the air box to get any air? I will try tapining off the headlight "leaks" but i am wondering if the 2 1\2" vents is enough air for the airbox??
 
the air box sucks air from up under the headlight area!
this NEEDS to be taped off and sealed all around headlight area
I run 2 flo-rites, ram air filters with the under hood dumps taped off, then I drilled a @ 1-1/2 hole in each ram air duct so it brings outside to the air box
 
02ViperMtn said:
Mod-It
I got a viper mt. The air induction channels as you said earlier are blocked off from the airbox and do not force any air into the air box. The box is sealed to the hood, yet there is no source for air to the area that is sealed off except for the round vents i have (which were there when i bought it used) and the under hood air that can get through past the headlight etc. Did the round vents come stock when the air induction channels are blocked off? If not, how did expect the air box to get any air? I will try tapining off the headlight "leaks" but i am wondering if the 2 1\2" vents is enough air for the airbox??
Click to expand...

BE AWARE, IF YOU BLOCK YOUR UNDER HOOD AIR YOUR JETTING WILL LEAN OUT SOME.

The forced air induction comes blocked on Mnt Vipers from the factory. The intakes on the dash are after market pre-filters from SLP called flo-rites. Stock Mnt Vipers took all underhood air to the air box. Look at the pictures of my sled above and block all the underhood openings that will let air into the forced air induction chamber. You only want cold air from your flo-rites in the dash going to the air box. They give it plenty of air, look at the size of vents on other brands of Mnt sleds, they are even smaller than these in a lot of cases. A pre-filter for the air box is also a good idea. I don't have one yet, and even with all the openings blocked off I still get a lot of snow on the air box filter. I shake it out two to three times a day to get the water out of it. It hasn't bogged or anything because of it, but you want to keep water out of the air box.
 
Interesting reading. Have powder bog on 05 Viper Mtn. We have some of the best snow we have ever had and am getting bog when sidehilling on right side. Thinking I will have to mod my exhaust deflector or taper the pipe. Pic is of stock deflector. A note about air induction area; even though there is a plastic cover on Viper Mountans, it will still let snow through the area without tapeing it off. We have had that area packed with snow and getting from there all the way to the top of the filter. I took electricians tape to keep snow from getting in there. I will be trying to seal off some of the other areas mention in these posts. Another thing of interest, I may try using a material called Organza for prefilter material. Read about it somewhere and checked it out at local material store. Looks like most prefilter material and its cheap.
 

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the main soure for snow getting onto the airbox on a viper mtn is from snow entering the engine bay through the large hood vents and then being sucked from the bay area through the opening around the headlight area under the hood then directly down on top of the airbox. I feel a lot of the bog is caused from steam. If you keep the throttle on hard it seems to power through it, but not with the same kick.
 
Hi guys....I have been reading these threads since they started and the under the hood air is the key. But on a side note. I have always had this problem with my sled and have never cut the flow rites in, but this year I wrapped my pipes with exhaust wrap and put the shields back on. (The insulation was gone and pipes were wearing threw the shields)(I only wrapped under the shields) I have done nothing else to combat the bog!! I was out in the powder last weekend with snow covering the hood and NO BOG! First time I have ever been able to play in the powder without bogging!! I was pumped!!! With my sled all warmed up my pipes with shields are warm to the touch. I have a SRX 600 not a MM but if you have triple pipes and want to help you bog tremendously wrap them up you wont be sorry! ;)!


Note: jetting too can be effected when you wrap up your pipes, So check plugs and piston wash!!!!
 
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i have an 01 srx 151 with stock pipes, attacc compensator, exhaust deflector, and cold air kit , with a pre filter . i was going to wrap the pipes but the wrap did not arrive before my last mountain trip.i added foam to the underside of the hood to make a better seal to the airbox bender gasket and i did tape off around the headlight, it only gets air from the cold air intake behind the windshield. i was riding at 7000' with -5 C temp and 2' fresh snow. snow was flying over the hood constantly ,it bogged badly almost unridable even though i had most of the vents taped up, when i was in the same location other times with good weather and no snow coming over the hood it ran great.i worked on it most of the day changing secondary adjustments ,belts ,plugs whatever i could try on the mountain. at the end of the day i pulled out the pre filter and it ran great, the wet pre filter was enough of a restriction to choke the engine at full throttle, i cleaned the filter with soap that night and dried it , when i tried it it bogged again so i removed it and rode without it . that day and the next i rode without the pre filter,snow was constantly flying over the hood and windshield and it only bogged when the foam filter on the airbox got covered with snow so every ten minutes i would shake it clean,i had removed the tape from the air vents except from the very front. i dont know if this will solve other peoples powder bog but it worked for me. i will try to increase the size of my pre filter because i want to keep snow out of the engine.
 
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