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Discussion Starter · #1 ·
Hello new guy here. I just picked up a 1999 MXZ 440 F/C which runs great once you get it started and warmed up. Problem is getting it started before my arm gives out. I have checked compression which is 135 psi in each cylinder so good there. New NGK plugs. The guy that I acquired the sled from said he removed the carbs and cleaned them and I'm thinking the choke plungers are out of adjustment or the air screws are not set correctly. Does anyone have a good procedure for adjusting the plungers and what the air mixture needles are suppose to be set at. Thanks in advance.
 

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What I do is remove the carbs from the engine so they can be rotated to get a good view from the inlet side. Start with the cables slack so you know the plungers are seated when the choke is off. Turn the choke lever to half choke. Then tighten the cables and look into the choke port with a small flashlight until the port is half open when the choke is set on half. Verify that the plungers are fully open on full, and bottomed out when it is turned off. Make sure when you are adjusting that the cable is in a natural position and not being pulled on.
 

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My 500 fan will start hard too if it sits a while....if I try pulling it instead of using the electric start. It had sat for 5 years without being ridden and the idle circuits were gummed up. I had to dunk the carbs and really blow them out to get it to run right. I have new needle and seats for it. They aren't in because it runs good enough that I'll deal with it for this mediocre winter. Anyways I got viton tipped needles. The guy at the parts counter said hard starting is most often attributed to leaking metal needles. They will let the gas siphon out of the bowls then you are trying to prime the bowls with the pump then start it. Or add a primer so you can shoot gas into the engine directly. It will get it to run long enough the pump will fill the bowls back up so it stays running.
 

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Discussion Starter · #7 ·
Tug_Driver thanks for the info. I have a couple carb kits on order and should pick them up Monday or Tuesday. I have a gallon can of Berryman carb cleaner. I will let them soak a while and blow out all the passageways and install the kits in them then adjust everthing back to stock set points and see how it goes. If that doesn't work I will look into fuel primers. Do you have any input on the Mikuni power jet kits that can be installed? Good or bad. I see them on DennisKirk website. Thanks Kelly
 

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I haven't heard anything about the power jets. If you bought generic rebuild kits be careful that the jets aren't different. I saw eBay rebuild kits for vm34's that came with 160 jets which is crazy lean for sea level but they listed probably 500 different individual sled models it was correct for!

I did 30 minute baths in the chem dip with the carb bodies, needle and seats, both jets and the emulsion tube since they are removable. I blew through all the circuits afterwards and really got the idle circuit clean. Now with the sled sitting cold from running either same day or next day it starts first pull. After a few days 2 or 3 pulls. Let it sit a week and it'll take 6 pulls to start. The dead give away is the bubble in the fuel line where the gas goes over the top of the carb and into the nipple. It has a bubble in it.

Oh a full tank works wonders. If the tank it topped off full the gas level in the tank is above the level of the float bowls so it keeps them full by gravity draining. If it's giving you fits try filling the tank or keep a small jug of pre mix handy. It's easier to pull the plugs than pull the sled over 50 times trying to start it.
 

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Discussion Starter · #9 ·
Tug_Driver after reading your last comment I'm pretty sure you have pin pointed my problem. There is air pockets in both fuel lines and the gas tank is on the low side. Fuel is siphoning back to the tank causing my hard starting issue. Obviously both float seats are not shutting off as they should causing the siphoning problem. I will have new carb kits from the local Ski Doo shop tomorrow. These kits are just gaskets, o-rings and needle and seats. By the way are you in or around the tug hill area?
 

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Make sure to disassemble the carbs before dipping. The Berryman's is great stuff but will tear up any rubber/plastic parts. I soak em' overnight when I do it.

PM your email and I'll send you a spec book with all your sleds data. Jets and plugs and screw adjustments.
 

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1. remove airbox

2 open choke wide open

3 insert 3/32 rod into choke hole, a heavy duty coat hanger cut to 4" should be ok

4 set choke lever to 1/2 open

5 raise or lower choke adjustment nut until you feel a slight drag on rod. Do both carbs until both same feel. Snug lock nut

6 check to make sure both close and seat, slight play in outer cable sheath

7 open all the way and look in hole with light, both should be the same

8 complete close is more important than open, I have see sled partial open flooding an motor and washing piston clean of lube oil
 
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