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I've had it with this mower. It is a old 90's craftsman riding lawn mower I got off a friend for free. The mower was sitting in his lawn for years so I asked and I received. I thought I would be a fun project but has turned into a nightmare. It has a 15hp Briggs ohv engine. When I first got it it didn't run but I put a new magnito and spark plug on it and it runs... But not very well. It will surge to high and low rpms. When too much throttle is applied or mower deck is activated it will start sputtering requiring me to disingage the mower deck and throttle down until it decides it wants to run again. I have cleaned carb very well, replaced oil, checked valves ... The whole nine yards but it still throws a fit and won't run... Someone please point me in the right direction

Next...adjust governor.


BTW, post engine's #s

Jack17 said:

Next...adjust governor.


BTW, post engine's #s

Click to expand...

Governor spring is dodgy.
Amounts to the same thing you point to but maybe worth
a look for the complete fix.

An oddball fault on these is the grounding wire for
shutdown, depending on which engine is being tinkered with
it may happen the grounding mechanism shorts to ground at revs.
Some ID would help, sure ;-)

KK

KrashnKraka said:

Governor spring is dodgy.
Amounts to the same thing you point to but maybe worth
a look for the complete fix.

An oddball fault on these is the grounding wire for
shutdown, depending on which engine is being tinkered with
it may happen the grounding mechanism shorts to ground at revs.
Some ID would help, sure ;-)

KK

Click to expand...

I replaced the governor spring and now it dies because the governor over throttles and it dies. But the governor isn't the problem. To me it seems like a fuel problem but idk. If too much throttle of the mower deck is ingaged it will start sputtering and smoke will come out and it will die and the model for mower is 28n707
The engine model number is 917.252512

Natebearcat61 said:

I replaced the governor spring and now it dies because the governor over throttles and it dies. But the governor isn't the problem. To me it seems like a fuel problem but idk. If too much throttle of the mower deck is ingaged it will start sputtering and smoke will come out and it will die and the model for mower is 28n707
The engine model number is 917.252512

Click to expand...

Are all the pulleys and idlers free spinning on the deck?
You may have a frozen bearing, causing the belt to smoke on the pulley...thus putting too much load on the engine.

You may have to remove the deck (simple job) and check everything out.

Natebearcat61 said:

I replaced the governor spring and now it dies because the governor over throttles and it dies. But the governor isn't the problem. To me it seems like a fuel problem but idk. If too much throttle of the mower deck is ingaged it will start sputtering and smoke will come out and it will die and the model for mower is 28n707
The engine model number is 917.252512

Click to expand...

Thanks... that engine info can be checked out.
I'ts only text noise but I am hearing you could check the air gap of newly fitted coil and the timing marks position.
Then get into the idle and fast run settings on carby... the "smoke" you are seeing is likely a flooded (fuel) chamber. Manuals for the model
should layout how to adjust the carby settings after timing and spark issues are resolved.

Cheers....
KK

shiftsuper175607 said:

Are all the pulleys and idlers free spinning on the deck?
You may have a frozen bearing, causing the belt to smoke on the pulley...thus putting too much load on the engine.

You may have to remove the deck (simple job) and check everything out.

Click to expand...

Yes they are all free spinning the engine only dies when under load like high throttle or engaging the mower deck

KrashnKraka said:

Thanks... that engine info can be checked out.
I'ts only text noise but I am hearing you could check the air gap of newly fitted coil and the timing marks position.
Then get into the idle and fast run settings on carby... the "smoke" you are seeing is likely a flooded (fuel) chamber. Manuals for the model
should layout how to adjust the carby settings after timing and spark issues are resolved.

Cheers....
KK

Click to expand...

So I adjusted valves with a feeler gage and adjusted the gap for the coil. I adjusted the carburetor mixture screw and it helped a little but when I manually open the throttle after a certain point the engine will start sputtering again and shaking a lot and I have to throttle down until the engine smooths out again. I noticed that on the part of the carb that you screw the float bowl on to there is a hole on the side where it looks like something should screw into, could that be a problem?

Natebearcat61 said:

So I adjusted valves with a feeler gage and adjusted the gap for the coil. I adjusted the carburetor mixture screw and it helped a little but when I manually open the throttle after a certain point the engine will start sputtering again and shaking a lot and I have to throttle down until the engine smooths out again. I noticed that on the part of the carb that you screw the float bowl on to there is a hole on the side where it looks like something should screw into, could that be a problem?

Click to expand...

Using a short length of maybe 3/16" nominal bore (ID) flex hose blow into that hole.
Any air entering the mix chamber after the meter device is going to screw over the engine operation. Find out if/where that hole leads to.
Sounds to me like there is a high speed problem with fuel or advancing the cam.
Man can fix that. Eyes and ears on, stay alert and
persistant ;-)

KK

Supplementry:
You do have the belts off engine pulley when doing your tests, hey?

KK

KrashnKraka said:

Supplementry:
You do have the belts off engine pulley when doing your tests, hey?

KK

Click to expand...

I don't have the belts off but I think I figured out a problem. In my engine that hole I was talking about is where the main jet for the carburetor is supposed to go and it's not there so I ordered one and hopefully that will fix it

Natebearcat61 said:

I don't have the belts off but I think I figured out a problem. In my engine that hole I was talking about is where the main jet for the carburetor is supposed to go and it's not there so I ordered one and hopefully that will fix it

Click to expand...

That'll do it. Well done

Leave the belts off to set engine speeds etc, the governer should pick up the load when the engine is put to work.
Post the outcome if you wish to.

Cheers

KK

KrashnKraka said:

That'll do it. Well done

Leave the belts off to set engine speeds etc, the governer should pick up the load when the engine is put to work.
Post the outcome if you wish to.

Cheers

KK

Click to expand...

I'll let you know how it runs when the part comes in tomorrow or the day after

Natebearcat61 said:

I'll let you know how it runs when the part comes in tomorrow or the day after

Click to expand...

Well that fixed it, it runs like it should now. Thanks for the suggestions that helped me realize the problem!