Rotax 582 start problems

[Jack0932 0]

I have an old Rotax 582 s/n 3971243, that's about a 1990 build and off a snowmobile - I suspect that makes it a 583 engine?.

Purchased on ebay supposedly in good running order.

I am a design engineer, and the last plane I flew was a Tiger Moth in 1949!

I have designed and built a novel form of rotocraft  and the Rotax is the intended power plant for initial static tests only, which I am now ready for.

 

My problem is that the engine refuses to start. Dribble some gas down the plug holes produces a second or 2 of firing. Likewise squirt some gas up the carbs get it firing for a few seconds.

I'm not an expert on most things including 2 stroke engines, so engaged a mechanic who is an expert on motorbike engines.

He checks everything that I have checked - spark, fuel, timing, but still will not run.

Get some advice from a motorbike fanatic who still races bikes at the age of 80, and he suggests the crankshaft seals may be shot.

So take a deep breath, drink a few beers, sober up and decide to strip down the engine to check seals.

Engine all looks OK inside and engine looks to have had low hours.

So start looking for ideas from the forum sites which leads me here! 

There is minor wear on the piston just below the only ring, which looks OK,  Other than a visual inspection I do not know of any way of checking the seals?

In any case even if the seals were leaking I would have thought the engine would still fire, but run roughly?

I new set of pistons, rings, seals, gaskets will set me back $450.

This old engine appears not to have any adjustment on the timing as pickup point is fixed and flywheel is keyed to the shaft.

One suggestion is that the rotating plate downstream from the carbs has been mounted back to front?

I would be very grateful for any suggestions on how to get this engine running?

Regards,

Jack. 

 

[akflyer 1427]

my guess is that the rotary valve plate is either not installed correctly, or the brass gear on the rotary valve shaft is fried due to no oil in the RV oil tank.  Does the engine have 2 plugs or 4 plugs in it?

 

If you could post some pictures it would help us out.

 

[Deejayel 1]

Spark plug gap? That has bit me in the past. .018.... Much more than that and she just wont start. Run yes. Start not so much.

[SkyPirate 8]

my 582 was so fussy that if the gas was a week old she flat refused to fire,..give her some fresh drink and she ran like a top

[Chewie 19]

Check compression?

Check carburetor settings?

Carburetor is clogged??

[akflyerbob 41]

Ive been messing with this snowmachine 582 for some time now.

It is indeed a 582 and not a 583, 583 has the exhaust valves.

The case is cast provision 8, but the bolt holes are not threaded.

Also and most inportant, the gear box surface is not machined to accept

a gearbox. It is single ignition.

I had a bad 582 case and was able to get measurements and a buddy

machined the case to accept the gear box with correct tolerances.

It turned to be guite a deal I didn't expect as looks can be deceiving.