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DA917H sputtered to stall while mowing...


Kenzen

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My DA917H was running great for about an hour, taking down some heavy lawn. Then I hit my "back 40" which has a steep hill and tends to bounce the tractor around a bit. The tractor engine began to surge when it was going up hill and being tossed around a bit. The surging seemed to be in sync with how the gas would slosh around in the tank. If I slowed down it would regain a normal 3600 idle, and then be ok for running across level lawn. Once I hit the hill again, the surging behavior repeated. Then, it stalled during surging and will kind of start on the choke, but not run normally.

I topped off the gas tank to see if bringing up the fuel pressure via gravity would help, but it had no noticeable effect. Since it sort of runs on the choke, I'm writing off an ignition problem. I'm leaning toward a fuel pump problem or the float/bowl is out of whack. Any thoughts on how to proceed troubleshooting?

Thanks,

Ken

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quote:Originally posted by 427435

Check float setting.


id="quote">
id="quote">That's where I was going to go after a quick fuel pump check. I rebuilt the carb 2 seasons ago but kept the original float - are these known to fail? (e.g. leak and sink)
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Ken,

1. drop the float bowl, you would be surprised to see the crystals I had in mine from the corn fuel deposits. Clean out any sediment.

2. Then try a "Sea-Foam" treatment (fuel and oil).

3. Also here is good advise on adjusting the governor that Al Eden (RIP) sent to me on 8/12/2011...

"The easiest way to do the static adjustment on a governor follows.

In the Briggs factory school they said just throw away all the stuff about clockwise and counter clock wise. With the engine not running, just take the governor arm and move it so it opens the carb wide open. Hold the arm there with the carb open against its stop. Loosen the shaft on the arm and turn the governor shaft in the arm in the same direction the governor arm went to open the carb up. Turn it until there is no slack in the shaft and with the carb still wide open lock the arm on the shaft. If the engine was just rebuilt was the old governor used. Was the gear white, tan or brown. If it was white or light tan probably OK. Dark brown has been overheated and should not be reused. It is not unheard of for these governors to fail, or if the gear is dark brown the gear to break. Unfortunately this is the very first part put in the block in assembly and it will require the removal of the piston, crank and camshaft. Hope it is just the shaft slipped on the shaft or something simple like that. Good Luck, Al Eden"

You should not have to "run on choke"

Good Luck

Wayneid="Book Antiqua">id="size4">

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Have you checked the screen in the tank on the fuel hose fitting. They are one of the first things I remove when installing an inline filter and they plug easy.

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Originally posted by RayS

Have you checked the screen in the tank on the fuel hose fitting. They are one of the first things I remove when installing an inline filter and they plug easy.

id="size4">
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70 micron filters are for engines with a fuel pump. Which his should have. I use the Briggs 150 micron red filters on my non fuel pump engines.

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All: Thanks for the guidance! I'm not going to get to troubleshooting for a week or so, but I'll report back on findings.

Ken

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  • 2 weeks later...

Successfully repaired. The carb was fine, and got a cleaning in the process. The problem was the fuel pump. I removed the upper pump body from the engine and there were two things wrong:

The first was that there was 2 small pieces of paper gasket (blue-grey in color) in the fuel pump body, one was stuck in the discharge check valve holding it open. I have no idea where these things came from, but the tractor didn't have a fuel filter until I put one in recently.

The second problem was the intake check valve was loose in its seat and ajar. I put a few drops of crazy glue on the seat and glued it back in. I figured cyanoacrylate would resist gasoline, and provide me a fast drying time.

After reassembly, and readjusting the carb, it runs great. The surging problems I had are gone.

Thanks for the help!

Ken

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  • 3 weeks later...

Addendum: This actually turned out to be a crank seal problem, that was leaking oil to the point that the governor couldn't keep the engine speed up. The hills made the situation worse. Lesson learned: If you're having surging problems, make sure you're not losing oil (pressure).

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quote:Addendum: This actually turned out to be a crank seal problem, that was leaking oil to the point that the governor couldn't keep the engine speed up. The hills made the situation worse. Lesson learned: If you're having surging problems, make sure you're not losing oil (pressure).id="quote">
id="quote">

I am curios. The engine we are speaking of should be a KT17, correct? If so, I am not sure how oil leakage, or low oil or oil pressure should affect the governor. Obviously none of the oil issues is a good thing, but the governor should not be affected by what you are describing. The governor and all linkages associated with it are mechanically driven on that engine. If I am incorrect or misunderstanding, let me know, I am always looking to learn.

I would also check the breather assembly. If these go bad, they tend to cause seal failures. Old style was a red rubber mushroom style valve, new style is a steel reed type valve, and is available at the dealer for between 15-20 bux.

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Having never taken it apart, I can't tell you. However the service manual cites "low oil level" as a "lacks power" problem, and the governor behavior was all over the place when the engine was lacking power. Maybe my logic is failed, but if this isn't the case, I still haven't solved my core problem. I'd hate to think it was because of engine friction....sm02BTW, here's what my engine looked like behind the flywheel from the oil leak. OO You can notice that the right side of the seal is slightly proud of the face of the engine - the leak was on the right side. The inside of the flywheel (with the magnets) as well as the sheetmetal was caked in crap as well. It's amazing the thing didn't overheat. I spent more time cleaning the engine than fixing the problem.

Dirty KT17 II from oil seal blow out.JPG

57e05e4c20e8d_DirtyKT17IIfromoilsealblowout.JPG.27fd44348b496986694b6efb37afb23e.JPG

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