My new 920 Diesel

artfull dodger · Oct 7, 2014

Went thru a few tractors, horse trading and upgrading as I went. Got where I wanted to be finaly which is the diesel powered 920, same as the Simplicity 7790. She starts very easily from cold without any preheat help but is wet stacking bad from to much light duty use. For those that dont know, wet stacking is where unburnt diesel fuel is dumped into the exhaust along with lots and lots of white smoke. Usualy the injector tips are fouled. To attempt to fix this, I will be working the engine really hard, first by finding something very heavy to pull around the parking lot at work. Then, hopefully running a snowthrower this winter if I can find one before the snow arrives. If she is still doing it next spring, I will get both injectors rebuilt. Cheers Mike

Wolfy · Oct 9, 2014

You really can not beat these old A-C's/Simplicitys. Tanks on rubber.

3930dave · Oct 9, 2014

Nice score. :thumbsup:

Here's hoping that all you need is some heavy work+injector cleaner added to fuel.

Rgds, D.

artfull dodger · Oct 15, 2014

I have the injector cleaner in the fuel, in the middle of rebuilding the mower deck so I can try to work her some before winter comes. Now I need someone near by that has some nice tall grass I can mow for free once it dries out around here. I will have the deck done by Friday, waiting on an idler pulley to come in. I set the valve lash tonight, front cylinder was out of adjustment on both intake and exhaust, so tight I couldnt get any of the feeler gauges in within spec and the intake was that way on the rear cylinder. All are set now with .002 added to each one above factory spec per a Lombardini factory tech I spoke with. Also found the fuel return line banjo nut was only in about 2 turns on the front injector, yet I was loosing no diesel fuel. So I am guessing that maybe its overfueling that cylinder thru slobber or sticking from lack of use. She sat for quite a long time before the owner before me got her. I am seeing more black/grey when I do a full fuel cold start by the book. Before it was all white. Blow by out the breather tube is nil, very little air movement by feel and nothing visable to the naked eye with a hot engine. So I am leaning away from stuck rings as that should induce quite a bit of blow by if that was the issue. I should have the correct oil pressure sender tomorrow, then once the mowing deck is done, I will have no issues opening her up for awhile under load. Mike