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My friend picked this sled up a couple of years ago and we have never gotten it running right. It is a bear to start and once you have it started it just does not seem to want to idle. Its like it is starving for gas. If its choked it will start in four or five pulls barely. You have to feather the gas to get it going and then you have to keep the RPM's up till its warm or it will simply stall. Once its running it runs strong as long as you stay on the gas but will not idle until warmed up really good and will not start easily.

I live in snowless Ohio so there is not much chance to wrench and test. This year I replaced the whole top end with a reconditioned monoblock from Millenium Tech, new pistons and rings. I figured this would fix the problem but it is a little better but its still there.

I am going to rebuild the fuel pump, check the pulse line and check the filter inside the tank tonight if those are good I may have to replace the crank seals. Can I just turn the motor upside down and pull the lower crank half without pulling the top of the motor apart? How do I do a leak down test? That should answere my seal question for sure.

Any help is appreciated. Jay
 

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Anybody have some hints on what could be wrong? My head is turning black and blue from hitting the wall so many times.
 

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Its hard to tell with the info described but often enough is something much simpler than the direction you appear to be going. Starting from the bottom, do you have adequate compression verified with a compression tester? Do you have fresh plugs in it? Do you have fresh fuel in it? Have you had the carbs apart? Main jet and pilot jets are clean? Have you confirmed the needle and seats are functioning properly? Have you confirmed the choke cables are adjusted correctly and they are lifting and seating as they should? It does sound like a fuel delivery problem. Will it run half-assed by yanking the airbox and squirting gas into the carbs? I would exhaust the fuel and electrical system possibilities before tearing into the motor.
 

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I also have a '94 xcr 440 sp. Make sure you have the 45pl-03 engine. If you do it was only made for one year. The porting, timing and jetting is all different for the -03 model engine. They love to run above 25-2800RPM. They also like the head pipe hot. It is the nature of the beast for this model. I've tried different mains and pilots, different clip positions, to no avail. I run the stock 330 mains and 40 pilots. As for clutching I run a white Erlandson primary with 10M weights that are heel cut to give more rpms for engagement.(5000) If your carburetion is right should start within 5 pulls with choke on. Once it fires I only half choke or will be a bear. Before you replace any crank seals spray some brake cleaner at the seal area while running to see if the rpms pick up. If so, replace seals. But I don't think you'll find that the issue. This motor is finicky to adjustments and temps. But they rock when running. Good luck.
 

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Thanks guys,

We got a couple of inches last night so I figured I would see if she would go. She started on the fourth pull with the choke and I nursed her till I was sure both cylinders were firing. Good idle after that. I then took her into the yard and realized I wound the secondary the wrong direction [:p]. Took it off wound it correctly and fired her back up. Sled seemed to do good for the few feet I rode it around. I decided to hold off on anything till the rings are seated. I will probably rebuild the fuel pump since its easy though.

I have already swapped the cylinders and have EC45Pl cylinders but have no number on them. They were renicked at Millenium Technologies for me. The compression was down to 95 on both cylinders and one piston was badly scuffed and the other had a skirt crack in it. That is why I redid the top end. I also rebuilt the secondary clutch and swapped the gearing back to stock as we put in a non-studded track. The previous owner had it geared down 5 teeth on the bottom and 1 tooth on top. It pulled like a crazy horse but top end really really stunk. Figured with the non studded track she would spin enough as it was.

When I pulled into the garage last night she coasted to a smooth stop almost put her in the wall cause I expected it to slow down quicker, at least I know the track is spinning nice with no binding.

We are going to take it out this weekend to do some testing and make sure she is ready for our trip in two weeks.

Jay
 

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a leak down test is difficult to perform to test the crank seals. the trick with the carb/brake cleaner is a good one. if there is a leak, it will affect the running quality of the engine when you spray the seals. to answer your question though, yes, you can pull just the lower case half and replace the seals. you must pull the stator to do so as well. just unbolt the case halves, clean up the sealing surfaces, pull the crank up just a tad to put the seals in, make sure the locating pins on the bearings are positioned correctly to sit in the grooves in the case, put the crank back in place, spread sealant, torque the case halves and you're done. if you need more info, please ask. -Polaris Doc
 
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