Kachess
TY 4 Stroke Junkie
Last year we got into very, very, very deep snow a few times and had a WOT bogging issue. The snow was flowing right over the top of the sleds and you were full into the throttle contiuously. The sleds would be fine for about ten miutes, and then would start loosing power at wot. If you backed off the throttle a little you could get some power back and limp along. If you let the sled sit a minute it snapped back to life and you were good for ten more minutes of full power before it started bogging down again. It would get so bad a few times that the sled would bog right down and stall the engine. We tried jetting up and down to no avail. Carb heat made it worse. One of my theories was that the carbs are heating up (no airflow through hood vents) like they do with carb heat is on. Anyone know why the sleds run crappy with carb heat? I also suspected vapor lock in the fuel lines and tried re-routing the lines away from the engine, but to no avail. I have also felt that maybe the undertunnel exhaust was getting restricted, but we are often in deep snow when we don't have the issue, plus the sleds would run fine for awhile before bogging out. We have big holes up high in the hood so the engine can get air. I've considered trying to run fresh air to the airbox intake (like the two strokers do), run cooling air across the carbs, installing an electric fuel pump like the apex, even extending our exhaust outlet. Our turbo has never had the problem. It doesn't happen often but when it does it sucks. Ideas?
culvert
Expert
I had this same issue first time out in waist deep fresh snow. I ended up dropping MJ several sizes and also install 2cool airvents, on both my side panels.
Never had the issue again and was riding with snow flowing over the hood.
Never had the issue again and was riding with snow flowing over the hood.
Frostbite
TY 4 Stroke God
I have run into the issue too but, not nearly as severely as you have Joel. I opened up (with a dremel tool) the molded in black plastic vents on the rear of the hood cavity. I think that helps let's more of the hot air out. I also plan to add some frogskins vents.
Maybe you don't have enough air volume and you need a bigger bread box?
I use a Holtzman ATACC on my sled too so, maybe that is helping me out?
I know that's any help to you but, it's sure nice to see you're still around on the forum.
Take care buddy
Frosty
Maybe you don't have enough air volume and you need a bigger bread box?
I use a Holtzman ATACC on my sled too so, maybe that is helping me out?
I know that's any help to you but, it's sure nice to see you're still around on the forum.
Take care buddy
Frosty
ski-bum
Expert
I had a similar day on the Apex with under tunnel exhaust. Same symptoms you described, so maybe not a fuel issue?
rideblue
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Had issues like that on my '03. Part is due to the coolant running to the carbs and the rubber flap over the carbs and the other was the fuel pumps getting hot and vapor locking.
Sounds like you have a switch in the carb heater lines and i always run with the switch off. Have taken the rubber flap off that covers the carbs? that holds in heat.
That all helped, but the only thing that fixed it was an electric fuel pump! I used a 9 to 14 PSI inline pump for a TBI chevy truck and an adjustable return style fuel pressure regulator set at 4 PSI. Found the parts at NAPA. Wired the pump to the headlight relay so if the sled went upside down it would shut off once the engine died.
Sounds like you have a switch in the carb heater lines and i always run with the switch off. Have taken the rubber flap off that covers the carbs? that holds in heat.
That all helped, but the only thing that fixed it was an electric fuel pump! I used a 9 to 14 PSI inline pump for a TBI chevy truck and an adjustable return style fuel pressure regulator set at 4 PSI. Found the parts at NAPA. Wired the pump to the headlight relay so if the sled went upside down it would shut off once the engine died.
BlgsRX-1mtn
TY 4 Stroke God
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Sounds like maybe you guys might have an issue with steam from powder melting on the hot engine displacing the air molecules under the hood (just a guess). If that's not the problem; I have no idea.
Jim
Jim
Frostbite
TY 4 Stroke God
I do remember wrapping my fuel pump in aluminum foil for some reason. There is a post on here on the topic, it may have been regarding hard starting after a shutting down a warm engine.
I plan to add some more venting to my hood this season because I don't completely lose power when I have two feet of powder on the hood but, the sleds perfromance becomes somewhat lackluster and anemic.
Frosty
I plan to add some more venting to my hood this season because I don't completely lose power when I have two feet of powder on the hood but, the sleds perfromance becomes somewhat lackluster and anemic.
Frosty
MSRX-ERNIE
Pro
BlgsRX-1mtn said:
thouhgt of the same thing. One of my friends with a 98 Mountain SRX had the same problem when powder went over the hood. The hot exhaust/engine made so much steam that the engine would be bogging all the time.
Erni
freelheeler
Pro
i've also had this issue, generally caused by... very deep snow 3-4 feet of fresh pow pow, rolling over the hood windshield etc. you know when you get off the sled and sink past your waist.
it appears the vents fill with snow and it sufficates my machine, power loss and bog. if i stop wipe the snow off and give the machine a second to rebound all is good again. till the snow piles back over the hood and fills the vents again. i've had days of constantly cleaning off the vents, and you're so annouyed you'll follow a trail or track to minimize the blow over snow.
i've been wanting to install a few vents behind the windshield so they're protected but haven't done it yet, thanks for the reminder i need to do something.
it appears the vents fill with snow and it sufficates my machine, power loss and bog. if i stop wipe the snow off and give the machine a second to rebound all is good again. till the snow piles back over the hood and fills the vents again. i've had days of constantly cleaning off the vents, and you're so annouyed you'll follow a trail or track to minimize the blow over snow.
i've been wanting to install a few vents behind the windshield so they're protected but haven't done it yet, thanks for the reminder i need to do something.
culvert
Expert
I would highly recommend installing 2cool airvents. I did this to my side panels and have never had trouble again.
I'm also running the ECP kit and found I needed to run 150MJ's instead of the 165MJ asked for in the kit.
I had the airvents installed and tried 162.5MJ, 160MJ, 155MJ, all ran boggy or lacked power when in deep snow and I would hit a certain elevation and sled would run like junk. I ended with the 150's nice tan color and ran crisp from 4-8000' in Valemount/ Mcbride area.
I still go back to my 162.5MJ for my flatland riding at 2000' in norhtern Alberta.
I'm also running the ECP kit and found I needed to run 150MJ's instead of the 165MJ asked for in the kit.
I had the airvents installed and tried 162.5MJ, 160MJ, 155MJ, all ran boggy or lacked power when in deep snow and I would hit a certain elevation and sled would run like junk. I ended with the 150's nice tan color and ran crisp from 4-8000' in Valemount/ Mcbride area.
I still go back to my 162.5MJ for my flatland riding at 2000' in norhtern Alberta.
Kachess
TY 4 Stroke Junkie
Anyone have photo's of their additional cooling vents? What material do you use? I duct tape up my front vents to keep snow from packing inside the nose, early in the season, so I never get air through there. I am also inclined to think an electric fuel pump might help. I've had half of the stock pump go out twice on a sled and it really sucks. Does the apex have one that would work? I'm not familiar with it. Too high of pressure? Any photos and specifics of the chevy pump setup? My Turbo's pump looks pretty chunky. There's gotta be something lighter.
