heat sinking? Too rich? deep snow bog

[Twostroke]

So I ride a IQR 800, ves, twins, head, pods, tons of vents, bored carbs, the whole deal. Sled rips until I ride super deep snow. with 12"-18" sled runs great, EGT's 1000-1050. Once I saw 1100 EGT on a firmer day on a long sidehill WFO climb. I'm okay with the sled running a bit cooler/richer up top, but could that be my problem?

The last two days it has been deep, 3ft of pow, basically bottomless. Sled still runs great UNTIL I get out into deep untracked snow, once it starts coming over the hood and handlebars it bogs, and gets worse and worse till it can't power it's self to move any more, If I hold it wide open it still can't move it's self, egt's will read anywhere from 450-650. Now if I were to jump into someones tracks and I can keep it from doing this, get the egt's back hot, once I get it cleared out I can jump back into the deep again but then the problem will come back, sometimes rather quick sometimes but if I keep it really screaming it won't happen for a 20-30 seconds and I can get some decent carving in, if I hit I really deep spot bbooooogggggg. Really a pain in a$$.

I have a good snow deflector for the exhaust, that is not the problem, I've experimented with it plenty, bigger and smaller. Same problem.

Could I be heat sinking? I don't think I am because it's never really getting that hot.

Running out of air? Don't know how to test for this? But I don't think this is it, all the vents get covered with snow but I'm sure it's not air tight. I have vented, sidepanels, shock towers, hood, headlights, and tach.

I honestly think I'm just jetted too rich, could this be the case? The load of the deep snow and rich jetting overwhelming the motor? It just seems odd that the motor would run richer on a deep cold 12*day then it does on a 35* firm day based off my egt temps that is, guess it's because of the lack of air flow causing warmer under the hood temps on the deep days?

Ideas? It's deep and I want to ride.

current jetting with pods and PAR 13.6 head
45 pilots
air screws 1.75 out
fuel screws 1.5 out (need to double check)
needle - 9dfh10-57 on the 2nd clip from top
290 mains

Sorry for the novel!

 

[Solarguy]

Sounds like lack of air, most all of the bog problems i have encountered in the deep have been lack of air....good luck.

 

[slyrydr]

lack of intake air or exhaust getting partially plugged...don't start looking for an exotic solution...it's going to be very basic, air flow...

 

[allied1]

SLP Powder valves

 

[AKSNOWRIDER]

SLP Powder valves

yep..or a flow rite in the back of the airbox, sleds starving for air.........

 

[AdrenalineAddict]

Not that unusual for a carbureted sled, plugged intake, sled goes rich and dies. The only way I could get my UBR900 to run with snow over the hood was to pull the fiilters.

 

[Twostroke]

I'm running pods, no airbox.

 

[assault 700]

foam pods suck just run pre-filters way more cfm or pipe the intake to the out side of the hood say like throw the gauge hole kinda like how the turbos do it

 

[Twostroke]

Im running k&ns with prefilters.

I've thought about running a filter out through the gauge hole but I roll my sled alot, so that's why I ruled it out? Worth a second thought? Make it so I can plumb it for deep days and pull it off for normal days? I don't see how it wouldn't get plugged or iced up tho

 

[jmathias]

What aout to much snow getting to pipe and cooling it off to much thus changing the sonic waves that make a two stroke work. Cold pipe versus hot pipe. Maybe try wrapping pipe with header tape or using frogskinz on hood vents to keep sow out of engine compartment

 

[Twostroke]

I did have the pipes wrapped last season and still had the bog. There is very little snow ever in the engine compartment.

 

[Mjunkie]

x3 or 4 or 5 (lost count) on intake air. All that snow is keeping your sled from breathing. Don't have a solution for you but that is what you need to play with to fix the problem.

 

[sled_guy]

Your problem is the pods. I know, you don't think it is, but it is. I've been there on a Polaris twin. You need an air box and seal it up and a clear intake to the outside. As soon as you load that hood with snow the underhood temps go through the roof, the air going into the motor gets stupid hot and your motor goes crazy rich.

I tested mine with a temp recorder because I didn't believe it. Under hood temps right at the pod intake would jump to 100+ degrees as soon as the hood got covered. Going from say 20 degree intake to 100 degree intake kills the jetting.

Figure out an airbox, seal it up to an intake from outside the hood. I've seen snorkle setups that work well for this.

sled_guy

 

[joshkoltes]

 

[Twostroke]

joshkoltes - good idea but where you have your intake routed to would get covered with snow, I already have a vent there and I rarely can see it, snow piles up on the top of the tank nearly to the base of the bars.

The airbox would be just as much work if not more then building a snorkel for this application and I think I'd still have the problem with a box because this hood is so flat snow just rides on it. I don't have a airbox to mod anyways so...

I'm concidering a couple things;

1) Taller windshield with more venting on the dash and on the console. My thoughts being that the taller shield will loft snow up and over the dash, keeping some vents free of snow build up. Right now it just piles on top of my gauge vent and dash vents.

2) Building a snorkel to come up through the stock gauge hole. Running it on deep days and back to my normal set up for normal days.

3.) combo of the two

 

[locknload]

Have you tried running it without the prefilters? Those prefilters do not breathe very well if they get saturated with the oil from the filters + the snow and ice build up makes it even worse.

 

[NapaMatt]

X2 you need different air box..!

 

[up-high]

get rid of the K&Ns. Had the same prob. The under hood temps also melt the snow and now your carb is inhaling water vapour. Get the cages. Unless you ride in a lot of dust?

 

[Twostroke]

Filters and prefilters stay dry, that is not the problem. I do not have snow and very little mositure under the hood.

Building a snorkel tomorrow, testing friday.

 

[mike_s]

Put an airbox on it. They dont hinder airflow, and they route cold clean air into the engine from a location that gennerally stays clear of snow.

If you insist on keeping the pod filters, Make sure that your exhaust outlet is sealed to the belly pan, this can cause the engine to ingest exhaust that is leaked into the underhood area, it doesnt take much, and when the outlet is burried in the snow regardless of if you have a deflector or not, there is a considerable amount of pressure there. Also, find a way to keep ALL of the snow out of the underhood area. And i mean ALL of it. When snow comes in and hits the pipe, its a two fold issue, you loose pipe heat, and you make steam for the engine to ingest. Lost pipe heat combined with the steam replacing incoming air combined with the fact that youre already running warm underhood air equates to a grossly rich mixture. Trust me, i ran pod filters on many many of my sleds, they do suck, there are better solutions out there. Unfortunately for some mods ive built they were the only option.