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Cushman Trackster

cheeto

New member
I've finally joined the Snowcat ranks! :punk: (My Rzr on tracks doesn't count right?) :biggrin:
Picked up a '74(?) Trackster this weekend. No long-term vision at the moment as I wasn't really in the market for one...I just ran across it and the price was right. I need to get it running better and play with it a bit to see how far into it I want to get restoration/modification wise.

Stock 29 hp engine.
The first major hurdle is that it's missing on the left (driver's side) cylinder.
Dry/cold compression in both was about 65. Not great but even.
Swapped the plugs side-to-side. No change.
Swapped the coil on that side from the spare engine. No change.
At this point I decided I was not enjoying doing this in 100 degree weather so we came to an agreement on price and loaded it up.

Manual mentions that this may actually be normal until placed under a load???

I'll do some troubleshooting sometime this week but thought I'd throw this out there in case anybody has some insights for me in the meantime.
Thanks all!
 

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Melensdad

Jerk in a Hawaiian Shirt & SNOWCAT Moderator
Staff member
GOLD Site Supporter
Welcome to the group.

Boggie gave you good information. Please post progress reports as things move along.

And remember we love pictures :thewave:
 

JimVT

Bronze Member
GOLD Site Supporter
good to hear you again. bring it to our next meet .
you could always open up the deep stuff for your tracked rzr.
jim
 

cheeto

New member
Spark is where I plan to start.
I originally thought stuck reed valves but that's when I was thinking there were reeds for each cylinder. Although I'm pretty mechanically inclined, I haven't played with 2 strokes enough. I understand the basic operating principles, I've just never been inside one.

Somewhere (here maybe) I read about someone having a broken tab on the timing collar caused by improper installation of the flywheel so that's in the back of my mind. I also scanned through that section in the repair manual that the prior owner supplied.

I'll pick up a battery today and see if I can get some things checked out. Unfortunately one of the "clutch" pulleys for the starter is broken. Looks like a simple repair with a couple roll pins holding the assembly together but it's the "easy ones" that seem to bite me in the butt. :)

If I can get it running well with this engine I have no plans on a swap at this time. The costs of a 4 stroke engine plus the complaints of lack of performance afterwards just don't interest me. Gearing changes just add more $$$.
 

Snowtrac Nome

member formerly known as dds
GOLD Site Supporter
Brad not onans but omc's the omc opposed cylinder engine was prone to burning the back piston from over heating. 65 psi indicates a real problem that one should be well above 125,any leakage around the rings will affect the transfer stroke when the piston's come down,and fail to properly pressurize the crank case to exhaust burnt fuel and allow for a fresh fuel air charge to enter. check for spark if it is good start looking for why the cylinder is so low on compression. that machine looks pretty nice I think I would look for a newer snowmachine engine to drop in for simplicity you could go with a fan cooled engine but a liquid cooled engine with a radiator would be cool.
 

cheeto

New member
Okay, got a battery and fired it up. Using a non-contact electrical outlet tester I'm showing nothing happening on the plug wire of the bad cylinder.

The two coils are wired in series so I'm wondering if this engine fires both cylinders at the same time or is there a wasted spark during engine revolution? I see no way for the coils to be fired individually when wired like this.

There are only 2 wires plus the plug wire on these. If I remember things correctly there should be continuity between the two wires but nothing between either of those and the plug wire correct? Primary coil induces voltage into secondary coil but has no physical connection?
They are DC but can reversing the wires on the primary coil cause issues? I was hiding in the shade when the seller swapped the coil out.

On a side note: I have no air cleaner cover and I think there is supposed to be a silencer jug attached to the intake? Anybody have samples? If I get it running I'll also be looking for images/pattern of the warm air covers that divert air from the hood vents back towards occupants.
 

cheeto

New member
Well, I swapped the coils from one side to the other. It runs marginally better. Still seems like left side is firing about half as often as the right side. The book specifically states that it can appear this way until a load is placed on the engine but I don't know if that's what is happening or if it has an actual issue.

I stopped into a couple local motorsports dealers today hoping some old-timers there might have experience with these machines. Although several employees were helpful there were customers at each that gave me contact info for people in the area that currently or recently owned one. This thing gets attention every time I stop (I've been dragging it around getting bids on the upholstery and fiberglass work). Never hurts to build a network of owners close by.

Hopefully I can find somebody with one that's running and compare my exhaust output to theirs.
 
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