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485 Venture Engine

9K views 8 replies 5 participants last post by  stevie.c 
#1 ·
What the heck is wrong with the 485 engine on my 97 Venture? Until it heats up it runs like a dog. It will idle for about 1 minute then foul unless I drive around and rev the crap out of it.
When warm it is fine. It has been like this from the beginning.

The dealer in High Level suggests that this is also true of the 485's in their fleet aqnd that's just the way they are.

Surely there is a fix for this condition?
 
#2 ·
I had a '91 Phazer II that had a similar engine.
It would idle fine for about 30 seconds and then the idle would slowly drop untill the engine stalled. I just put on all my gear before I started the sled (it always started on the 2nd pull) and then while I waiting for the people I ride with to get ready and get their sleds warmed-up, I would just crack the throttle open enough to hold the revs at 3,000 rpm.
After I rode the sled a mile or 2 it would idle just fine.
You might want to pull your pilot jets and see if theres any varnish in them.
Personally, I think its the carbs. My XC has very similar carbs and it does the exact same thing. It wont idle on its own when its somewhat warm (but not up to operating temp) but once the pipe warms up its fine.
I guess its just the nature of the beast. :dunno:
Cap'n
 
#4 ·
Dont worry about it. Just wait untill the idle starts to drop crack the throttle open a bit to keep it running and then just drive kinda slow for the first mile or 2 (something you should be doing anyways) and you will be fine. :dunno:
Its the carbs. With flatslide carbs you give up some running quality to get a light throttle pull.
Cap'n
 
#5 ·
Thanks Capn....the problem is running slow won't do it in cold weather as I will foul a plug. Driving the snot out of it seems to work well. I don't like doing this to a cold engine.

Carbs have been cleaned and recleaned and are properly jetted. Any way to switch to a less finicky carb?
 
#6 ·
When I say, "drive it slow" what I really mean is to not run the engine hard for the first mile or 2. As long as you keep it under 6,000 you should be fine. Thats how I rode my '90 Phazer II and I never fouled a plug. :dunno:
I dont think different carbs are going to fix the problem. Fan-cooled sleds are usually cold-blooded. They have to be setup really rich to control combustion chamber temps and they also have the fan that extends the period of time that it takes for them to warm up (as compared to a liquid-cooled sled which heats up rathar quickly if you just let it sit and idle).
I think that its just the sled's personality and you are just going to have to learn how to live with it. I know that it drove me crazy when my Phazer would idle like that but to be honest with you, the '01 Polaris 600 that I have now does the exact same thing.
Cap'n
 
#8 ·
I got a '92 Phazer and a '93 Venture with the 485 fan motor, and they are both the same way. Never caused any problems and both sleds were ridden buy people who weren't too aware of the 2-stroke motor and how they like to be run. :m2c:
Brad
 
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