tnt 440 help - Snowmobile Forum: Your #1 Snowmobile Forum

Toehead · 07-08-2007, 09:26 PM

Hey all.

I got a free 73 TNT 440 today. Inspection of the wiring diagrams seems to show that it has a 76 engine, as the 76 diagram matches exactly and the 73 is not even close.

The probem:

When I got it, it was sparking on only one cylinder. I took the magneto apart, and found a wiring mess and a missing woodruff key.

What size is the woodruff key on one of these engines?

Toehead · 07-09-2007, 08:34 AM

I am also interested in purchasing a magneto for the sled. The current magneto has a few problems. Apparently the fan broke a blade and the shrapnel ended up inside the magneto. The previous owner replaced the wires, but you can see where the magneto magnets were a little chewed up.

Toehead · 07-09-2007, 09:33 PM

Also, what is the correct procedure to set the points on these?

Thanks

**RJ Gleason** · 07-09-2007, 10:02 PM

If someone else does not give it to you, tomorrow I will post detailed instructions after referring to my shop manual.

Toehead · 07-09-2007, 10:31 PM

Thanks man.

I am having a hell of a time getting this thing to spark. I really need to find a junked 440 motor to steal the whole magneto from. The motor only has 1000 miles on it, but the magneto is a bit dodgy.

**RJ Gleason** · 07-10-2007, 06:51 PM

Hope that this will.

We'll start with the engine spec's. 71 T'nT 440 Model 435 Rotax engine Axial fan cooled with a Tillotson HD carb. The actual displacement is 437cc. Ignition is type ET, the point gap is 0.014-0.018. with timing advanced. Set at BTDC 0.110-0.113. Original spark plug that was used was Bosch W280T1 set at 0.020. the oil mix is 50:1 if you use the Bombardier concentrated oil. Otherwise mix according to oil manufacturers directions. Usually 40:1 when using full synthetic oil and 30:1 using Dino oil.

The model engines with Energy Transfer (points) ignition have timing marks on the flywheel and fan housing. (at top side of recoil mounting) Timing is correct when the breaker points just open when the timing marks align, with the advance mechanism in retard (static) position.
Timing may be adjusted by varying the point gap within the limits stated above. Magneto edge gap is fixed and will be correct when the breaker point gap is properly adjusted and the advance mechanism operates properly.

Toehead · 07-10-2007, 07:32 PM

Followed the procedure... Still sparking on the left (ds if a car ) cylinder only. I took the magneto completely apart and cleaned everything. both sets of points are correctly gapped and are working properly. Both coils work.

I suppose the only other thing it could be is the condenser on that side.

Thoughts?

Thanks for the replies

Toehead · 07-10-2007, 09:54 PM

Also.
One of the magnets on the magneto is missing about a quarter its size. The metal casing is still there, but the magnet underneath is broken.

Now for the darndest thing...

It switched sides.

Now its sparking the other cylinder. There must be a short somewhere.

Toehead · 07-10-2007, 10:24 PM

found it.

All is well!

Thanks!

Toehead · 07-12-2007, 12:37 AM

Examination of pictures leads me to believe that it IS a 76!

It is clearly a 76 Everest.

Why does it say manufacturers date :1973 on it?

I may need to take some pictures for you guys!

Toehead · 07-12-2007, 02:28 PM

I got it running and idling nice

IT seems to run very well.
The cvt Primary is very sticky, and doesnt shift... so that is the next project.

Rj, does your manual say what the default mixture settings are for this sled? It is a tillotson carb.

Thanks guys !