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Got given F.O.C. a 1995 MX 470 two weeks ago by my Boss. He'd had the Doo back to the stealership he bought it from to have a burnt piston replaced, then again two days later with a problem of coolant filling the crankcase - not a good sign. The stealership skimmed the head, told him it was good to go, and then went bankrupt before he could send it back to fix with the same problem (this Doo was one of the last ones to be touched there, they closed down 2 days after returning it).

The old girl's future did not look promising. After a "tech wizard" at work failed to fix the problem, the water was drained out and the engine was filled with oil in hopes of someday getting her to breathe again.

Two years later I asked what he was doing with it, he handed the key and title to me and said "giving it to you" so I found a new toy to play with (first snowmobile for me - I'm from England, they are not too popular there).

OK, out with the wrenches! Drain the oil from the crankcase, then head off, checked and looks fine. Fill the cylinder water jackets with coolant and hand crank the engine and look for signs of a leak...

Bubbles from one of the cylinder bolts on down stroke!? that can't be right, oh look, the bolt isn't even clamping the cylinder down, hmmm.....

ok, pull the cylinder off, chunk of gasket missing presumed dead and lower cylinder face nice and true (amazed since one corner not clamped that it didn't warp any).

Now, lets check the other cylinder, Bolts clamping, face true, all looking good.

New gasket set scavenged from friend who knows this guy who knows this guy, who dates this girl, who knows this guy, who knows this Doo dealer (may have missed a couple of guys and girls in there, can't remember the full chain of people).

Gaskets on, cylinders on, bolts back in the CORRECT holes (looks like the tech that did the piston swap got the bolts in the wrong places - two different lenght bolts, one in the wrong hole), clamps down nice and no air bubbles in the water jacket, head back on and looky there, not losing coolant any more, things are looking up!

Now since she's not had anything to drink for a couple of years, drain the tank (full tank of 2 y/o "gunk" - tho it did burn when diluted into the tank of my truck), pull the carbs, good cleaning, put back together, put some fresh burning water in the tank, final check over the pipework and wiring, pump the primer a couple of times and give her a pull...

HOLY S**T!!!!! second pull and she's purring like a kitten (and smoking like a house fire) Praise Snowmobile World for letting me find base carb setup specs to use SWRules

After running up to temp, shut her down and check her over, looking great, time to brag to the wife about the new toy that I can try to kill myself on.

Test drive aroundown the driveway gives an awful clunk from the track, oh no, not a seized wheel...

Nope, track tension way too tight, 1/2" droop with the spec'd 16lb tension, adjusted and sounds fine. Next problem is a lack of brake light, re-insert wires into switch, job done. Only one problem left, no snow!!!!!

Problem solved a couple of days ago, 4" of nice soft, fluffy white stuff (no, not that stuff, I'm a good boy - I write like this all the time, it's not chemically induced). Time to give her a test on the stuff she's built to run on...

Jeez, ease the fun flipper and she's moving, try to take it easy to break her back in again, no chance, she won't let me, first run trying to be gentle found me blasting across a field doing 75mph and then launching a couple of feet in the air after finding a hump I never found with my ATV last time out.

So much for a gentle test ride eh?

After an hour of testing (testing - read playing) the boss drives past on his way home to see his old Doo screaming across the fields behind the house, I wonder what he'll say tomorrow? guesses anyone?

Now there's only three questions I have about the old girl...
1. Where should the fuel pump mount? It was unsecured on the pan, under the engine, just rattling about, I couldn't see/feel any mounting for it so it is currently living on the front of the airbox with help from two big screws until I find the correct home for it.

2. What holds the brake rotor onto the shaft? There's a rattle from it when changing speed, looked and I can't see any mounting on the rotor hub, guessing it's located by a wudruff key but I don't want to rip it all apart to find out that it is meant to be that way - I'm pretty sure the rattle isn't standard, but after getting her running, and then getting snow, I don't want to pull her apart again just yet.

3. Any free/cheap mods to make this machine better, anything, from DIY superchargers to fuzzy dice brackets, I can't afford to spend $$$ for new toys when I don't desperatly need them (sigh).

Sorry for typing a novel, just happy to have revived a nice old machine and to have lost my snowmobiling virginity.

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[attachment=33433:Ski_Doo_001w.jpg]
 

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oldslowsledder
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Can't help you with your questions but welcome to the site and congratulations on giving the old girl by-pass surgery!!
 

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Discussion Starter #3
thanks for the welcome, I'm now trying to talk my mother-in-law into babysitting for the afternoon so I can go and doo some more "testing" hehe
 

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thanks for the welcome, I'm now trying to talk my mother-in-law into babysitting for the afternoon so I can go and doo some more "testing" hehe[/b]
my fuel pump is below my carbs, cant see the screw holes that hold it, I will take an old sled over any new one any day.70&80&90ss why spend 7 to 10 grand on a sled that you cant ride, cause no snow. you cant do 120 in the trail, only on a lake, 340 & 440.the best for everthing.gas mileage.trails.and even crossing lakes realy,, because you dont have to worry about the bump you just hit clipping over 100 mph that sends you to flight school 101 been there done that.I like that mxz 440.next season i will be going back to the 440s all around great sled. Ill give a 1000 bucks for her.Crash dummy
 

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Welcome to snowmobileworld :christmas:


Does that sled have a mechanical brake? if so they tend to make that tin rattling sound.
 

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Discussion Starter #6
Crash Dummy, Thanks for the PM, I'll be checking into a Wis. trip, Boss has a cabin 3 hours north of here (unknown location) and father-in-law has one about 6 hours away near Ea-Claire. I'll have to have another scan for the correct pump mounting holes, but for now being on the airbox is better than bouncing aroud on the pan under the block!

I have no idea what era sleds are better for any particular purpose, but the MX is fine for me, comforatble enough for cruising around, ride isn't too harsh, but then it's got enough grunt to kick you in the back when you want to get the speedo needle up near the triple digits.

Thanks for the $$$ offer too, but I'll have to decline, I've been for a cruise around the local trails today (Silver Springs - Yorkville, gravel/mud/grass tracks around 2 small lakes, nothing remotely difficult) and I enjoyed getting out there and forgetting about the rest of the world for an hour, I sure could use the money but I'd never be allowed to buy a replacement sled and I'd miss having the toy around.

G. Davey,
It does have the mech. brake, after looking thru more of the older Doo posts on here (I'm up to around page 125, just another 500-600 to go) It looks like it is just located by the wudruff key (keyway to non-brits) and I guess mines worn so theres some slop in the joint, I don't hit the brake hard enough for it to be an immediate tear-down so I think this spring/summer I'll be pulling the shaft and replacing the key - probably a good idea anyway as it seems I'd have to pull the chaincase apart to do it and I want to check the state of the internals before next year.

Thanks for the welcome guys, the more I read on this site, the more I'm loving the sport and the more I respect the people on here.

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Beaver, I'm sure I'll have more hours wrenching on the Doo than hours riding, but it is deffinetly worth the trouble to be able to get out and ride for a few hours here and there. My only problem is it is going to kill the gas budget for my truck since I'm sure I'll be taking vacations to the cabin in WI a lot more often than usual! hehe.

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Adam,

Usually the woodruff key and shaft become quite worn. If the rotor doesn't have too much LRO (lateral Run Out) you can get a machine shop to cut another keyway in the oppsite side for around $25.00. I have found most used shafts on EBAY to be in the same rough condition. Another trick is to apply some Loctite #609 Sleeve adhesive before you slide the rotor onto the jackshaft.

Goodluck !!! and welcome aboard mate !!!

Cheers T.D.
 

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Discussion Starter #10
TD,
"cheers"!? You a brit?
Where I work I have access to lathes, mills etc. so I can fab a new key to remove the slack, there's probly around 1/2-3/4" play in the disc. I was just curious if and why that was the only locating method for the rotor as keyways put under load usually wear and a brake system is not the best place to have worn parts.

Thanks for the welcome.
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Liverpudlian family history(Scowsers(sp) born in Boston Mass. The disk set up has been that way since I can recall. (stupid really). The key gets backlash and heat & cooling cycles from braking action. The caliper locates the rotor on the jackshaft. Usually the rotor seizes and the inside brake pad wears out prematurely. I've had good luck Knurling the shaft to restore loose fitting rotors and as said, cut a new keyway 120 degrees from the original one and glue it with Loctite 609. The rotor needs to have lateral movement as the brake pad wear.
 

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Discussion Starter #12
From liverpool eh? I used to work in Maidenhead for a couple of years, travelling from Carlisle.

Thats what I was thinking with the shaft, cut a new keyway rather than trying to machine a new key to take up the wear in the old slot. 5 minute job after the hours of swearing trying to get the shaft out! I'm guessing chaincase teardown job just from a quick look at it.

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