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under tunnel exhaust?

i bought an under tunnel exhaust and boss seat back in november for my 07 apex se, and got it all installed and it seemed to be working great , loved new throttle response. Now that ther is lots of POWDER it feels like its occasionaly "stuffing up and cutting out" on me. The shop I bought the exhaust from said it needs more air under the hood and maybe an airbox mod and that i should put a vent kit on. They claim it will flow more air and not cut out. Is this true? I have no clue. The vent kit is 360 bucks so its not cheap. would have been nice to know up front.
 
has anyone had this problem? I put six 2 in holes in each side and used aluminum screen and slp pre filter material to vent it and it helped a lot. But I went out today , It was the best deep snow i've ever been in , and i'm still having the dang thing cut out. Bad when I get the whole front end burried with snow. I have to stop and clear it all off so I can keep going. I'd like to find a way to get more air in the air box but I can't find anythink that looks like it wont suck in snow. any help or suggestions would be appreciated.
 
I drilled mine underneath with 4 more holes, one in between each plastic stiffener just up from the stock intake opening so it still sucks from underneath above the battery. Haven't been in any huge powder though.
 
did it help get more air in the air box? did it affect the way the machine runs good or bad. i was considering putting in some uni filters, but dont want to have to but a new airbox if it dosent work.
 
What if its the exhaust that is getting plugged up from the deep snow? The track would be throwing snow right at it. Mine did this last year on a trip to the mtns. I figured it was bad jetting but I wonder if its not the exhaust pluging up and causing a rich condition?
 
I could never figure out how it could work ---- there will be a pile of back-pressure in powder. How about putting on a 180 degree bend and face the exhaust forward with the rotation of the track that should fix it.
 
What if its the exhaust that is getting plugged up from the deep snow? The track would be throwing snow right at it. Mine did this last year on a trip to the mtns. I figured it was bad jetting but I wonder if its not the exhaust pluging up and causing a rich condition?

Mine does fine in deep snow until I get into over the hood conditions, then I start having problems. This is why it seems like an intake issue to me.
 
troy at tj's swears to me that it is an intake / air issue under the hood. I talked to him today and he said i can open the bottom of the air box some where it draws air, but he said it is really a problem with not enough air available under the hood. I guess i'm just going to make some more vents and see what happens. when i stop and clear the snow off the hood it almost instantly clears up so it makes sense. when the hood is above the snow i can run wide open no problem, but if i'm boondocking down hill and cut back up i'm dead. so i dont think its plugging the exhaust.
 
I have yet to hear of an Apex with the stock exhaust location bogging in deep powder. The intake may be the cure but the under-tunnel exhaust is where the problem begins. Any 2-stroke I ever had did the same thing especially when tipped on the exhaust side. There are ways to overcome it like more intake, exhaust deflectors. Never bogging in deep powder is one of the many things I really like about my Apex.
 
my brother was with me sunday and his apex is stock and he did experience some problems, but not nearly as bad. for the most part his was fine,but when he cleared the vents mostly the 2 hood vents he said it reved quicker and higher. mine however ran half power when all clogged up. i agree the under exhaust caused the problem but if i can make it work it will be better everywhere....
 
What about riveting a deflector on behind the exhaust outlet. Keep it a couple of inches behind and a few inches wider then the exhaust and it should deflect any snow, the heat should keep it clean of snow buildup and the gases should still be able to escape around it... I image that it would be less restrictive then a 180 degree turn in the pipe. This of course assumes that there is enough clearance between the track and the existing shroud.

Deal with the actual problem, getting more air in only solves part of the problem, while it may not bog, as enough extra air can get in to compensate for the fuel rich environment, the engine still wont be able to produce full power, cuz spent exhaust gases wont be able to escape from the combustion chamber.

Just my $0.02.

Have Fun
T
 
I dont have a pic of my exhaust, but will get some. I added the side vent kit to my RX-1, I also dropped a couple more sizes on my MJ. Other than that I didnt do anything with the exhaust.
Heading to Valemount on Wed and will let you know how it works out. Only get 1-2 trips a year to the Mtns so I hope things are better than last time out.
 
If you want to somewhat keep the stock look/parts, install mesh top & side panels on both side panels, go with a mesh hood and put in Ulmer's bellypan vent panel. I have this set-up on my RX-1 and it breathes really well & we have a similar set-up on an Apex Mtn. with a different solid type hood, the engine area really breathes great and helps with the heat (for us boosted guys). The only problem with OTH snow is the s/c oil getting too hot from no frontal air, but the sled still runs strong. The R&M fabric - snow falls right off and water beads/falls off also - great product.

sideApexMtnventing.jpg
 
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Installed tj exhaust on my 06 apex and have the same problem. Rode in 2.5 feet of powder yesterday and when I would come to a stop the engine would bearly idle, wiped the snow off the two vents on hood and the side ones and idle came back to normal. Going to install timbersled air vents this week and see if that improves it.
 
well i stripped the sled back to the tunnel last night and did some more metal cutting and was able to raise the level of the exhaust up about 1/2 inch. The exhaust exit used to be flush with the deflector shield and now it sits up above it , maybe this will act like a shield on a 2 stroke and create a little buffer zone so the exhaust can excape better. if it helps i'll post a pic. I'm also going to do some more venting anyways, It can't hurt! I saw on the web 2 cool air vents, looks pretty nice, talked to them yesterday, think i'll try it. Hopefully I can get back to just riding and no wrenching....
 
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