Smta still not running right

Mayer1466

Member
My smta still chokes out and smokes brown
puffs till it dies when put under load. It
Has lost half it's power. It can't take off
in 3rd gear anymore. I tried cutting hay but
after 5 hours in 1st gr. Burning 12 gal of
gas and a gallon of antifreeze. I'm thinking
about tearing the engine down. Does anyone
have any ideas to try before I tear it
down.. been dealing with this for 6 mo and
in that Time I rebuilt the disturbtor, all
new ignition. Fouled out a couple sets of
c87 right now it seams to be doing better on
the champ d16's. I put a new kit in the carb
and even had a shop sonic clean and test it
the 2nd time pulled the carb off. I took the
plate off the govener, but didn't see
anything that looked out of place while it
was running. I have checked the valve
clearance twice. I also looked at the push
rods and rockers but didn't look like any
thing was wrong/bent. Im 98% sure the head
is cracked but I wouldn't think that would
be a cause of my problems? Maybe someone
else has an idea or 5 things that I can
check for before I diss assemble the motor/
head.
 
As poor as it is running, there may be cylinders misfiring. Pull off each plug wire one at a time (with insulated pliers) to see if any of them make no difference. If so that cylinder is suspect. Loosing coolant is a No No. if the oil is contaminated with coolant, you will wipe the bearings out of the crankshaft quickly. Do not operate it in this condition. Jim
 
Our 450 sheared the cam gear key and then a piece of it wedged into the gear enough it would still turn the distributor, and had also brole off some of the teeth too. Started running all over the place, poor, better, worse. Timing was never right. ? Maybe


Ross
 
My 350 sheared the key off that ran the hydraulic pump and distributer. This caused the timing to get all screwed up. Tractor had very little power and actually got warm. Had to replace pump and now running good. Not sure if this is the problem. Just a idea.


Thanks Todd
 
I would agree with the 2 posts below. When I first got my SMTA running it wouldn't start very good and low power. It had chipped the end of the cam shaft where it foes into the gear. You can pull the distributor and hydraulic pump off and check to see if timing gear is tight.
 
have you checked the compession??? that is # 1 on the list any time engine problems are encountered, or when a tune up is done. it is possible you have a head gasket burnt between two cyl's. that sure will cause you to loose power. but you should be able to hear the miss though. its not nessessary to tear down an engine till you find out the problem first. did you look in rad to see if you have compression bubbles? reading the spark plugs tell a story too. maybe the antifreeze is going out the exhaust ... like it has to be going someplace if you cant see any visual leaks. and you think you have a cracked head and its not the cause of your problems.? you also did lots of checking but have given no spec's as to what things are set at or carb adjustments. a person needs this info. is the main jet on the carb opened at least 3 turns??? is the float ok?, and not heavy? what is the valve lash set too? you need a manual to adjust the governor. have you checked the timing? are the points set to spec.? you have to start with a compression check to know the engines condition, that is one thing that nobody does other than guess at thinks.that should give you at least 5 things to check on. an engine can be worn right out to reason and it still can be made to run as long as things are set to spec.
 
I don't have a manual on hand but have read many posts on setting the carb, fuel level, valve lash
Timing ext.. I went out tonight and rechecked the compression and I think that's shedding some light on the issue. The compression was only around 60-80 cold and 70-90 warmed. There is no deffinet miss until it fouls a couple plugs..the tactor also starts on the first pop..
 
No there never was bubbles in the radiator and u didn't adjust the govener I just opened it up to see if there were any broken, bent, stuck parts.
 
Tractor was rebuilt in 84 85 w/ih overbore high comp pop up pistons. M&w govenor and throttle handle ran 68 on dyno. We never had to touch the motor till 3 years ago the original head cracked. Was quoted 700 to fix it. I opted for a tested used one but now I think I'm regreting it.. the original head before I changed it 3 yrs ago still had over 100psi comp so I didn't change the rings at that time.
 
Time for a top end rebuild at a minimum. Mic out the rest while you have it opened up and replace what needs to be replaced.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top