# Kohler 6.75 repair issues



## Jf1985 (Mar 31, 2019)

Good evening. I have a Toro with a Kohler 6.75 on it. Ph xt675 2070 is the model. I cannot get it to start without ether. Now once I get it started it will stay running and will start when its warm on the first pull. And when I shut it down it does a backfire a little. Now here is what i have done so far, it's a repair for a friend and this mower sat in a shed with gas in it. So the carb has been changed, the ignition coil was bad with a ohm reading of 12. So it has been replaced. I drained the gas cleaned the tank. Replaced the fuel line. Changed the plug. I have a compression tester that screw into spark plug and it was at 80 or so. I checked the flywheel key just for fun and it was great not off at all. I'm looking for ideas at this point. I did pull the bowl and gas flows fine. When it wont start and i pull it 4 5 6 times I can smell gas in the carb. And like a said a shot of starting fluid and it fires first pull and will run fine.


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## geogrubb (Jul 28, 2006)

To me it sounds like there is an air leak, while it is running spray/dribble some carb/brake parts cleaner behind the carb and along the mating surfaces, if the engine tempo changes you have found the leak and can take the appropriate action. Have a good one. Geo


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## paulr44 (Oct 14, 2008)

The XT's had a choke problem, mostly related to hot re-start but can affect cold start - I've changed a few of 'em.
Kohler service info. is free on https://pswusers.arinet.com/kohler
Scroll to bottom and enter as <guest>.

Ensure choke is closing fully, if so problem is elsewhere, perhaps vacuum leak as suggested by Geo.


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## finaprint (Jan 29, 2006)

X2 on chasing the choke. 

Backfire after an engine kill may be nothing, the throttle plate closes off at rpm drop and then the higher decel vacuum spreads the air out to misfire as density is lost. Where the popping comes from. Not true backfire which comes out the carb backwards, rather slow burn or afterburning in pipe. Two somewhat different things.

Hope that new coil got set close, if not that can make starting problematic too. Closer is better as long as no physical contact is made.


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## P-Paul (Nov 15, 2020)

I have seen wear in the upper crankshaft bearings in excess of 8 thousandths and the seals are not leaking.
This type of wear will make setting the coil gap rather tricky.
Rotate the flywheel so that the magnets are directly under the coil. 
Place a business card between the coil and the flywheel.
Loosen the coil bolts.(loosen only enough that the coil can move)
The coil should have been attracted to the magnets.
Push the flywheel toward the coil and while holding some pressure to the flywheel,snug the coil bolts.
Check for slight drag of the business card in between the flywheel and coil.
Done.
Button her up.


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## Karpo (Jul 8, 2021)

Jf1985 said:


> Good evening. I have a Toro with a Kohler 6.75 on it. Ph xt675 2070 is the model. I cannot get it to start without ether. Now once I get it started it will stay running and will start when its warm on the first pull. And when I shut it down it does a backfire a little. Now here is what i have done so far, it's a repair for a friend and this mower sat in a shed with gas in it. So the carb has been changed, the ignition coil was bad with a ohm reading of 12. So it has been replaced. I drained the gas cleaned the tank. Replaced the fuel line. Changed the plug. I have a compression tester that screw into spark plug and it was at 80 or so. I checked the flywheel key just for fun and it was great not off at all. I'm looking for ideas at this point. I did pull the bowl and gas flows fine. When it wont start and i pull it 4 5 6 times I can smell gas in the carb. And like a said a shot of starting fluid and it fires first pull and will run fine.


I had the same issues. Rebuilt carb,new plug, checked key way for timing, reset Magnito distance, flushed fuel, cleaned fuel filter in sending port of gas tank, still wouldn’t run.
Decided to go for broke , pulled the head off, intake loaded with carbon as well as piston head. Got degreaser and fine 220 emery paper and cleaned 99% of carbon off.next took valves out and cleaned valve seats in head as well as valve edges. Degreased everything and reassembled. Sprayed ether in carb, stated on fourth pull and ran. Two days of effort to find valve seats were fowled. Hope that helps you .
Sk


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