Trouble starting B&S Quantum when hot

[MI_Roger]

Originally Posted By: bubbatime
Originally Posted By: MI_Roger
Valves have never been adjusted. Only mow a 5,000 sq ft subdivision lot so not a lot of use compared to landscapers and large lots.


Assuming you have the flathead Briggs engine, there is no (easy) valve adjustment. The only way to adjust the valves is to take the (usually exhaust) valve out and grind the top until it is back into spec. Not a very common repair, but does happen sometimes.


Yeah, I knew they were having their fun with me. I almost responded back that the engine was running a custom built OHV head with roller followers. But that would have eliminated getting helpful suggestions from everyone else.

 

[Merkava_4]

Originally Posted By: Warstud
Next time it doesn't start....check for spark...your coil may be shot. If it isn't that maybe it needs a valve adjustment.


How do we know it's an OHV without the engine numbers?

 

[Lubener]

Originally Posted By: Brybo86
Originally Posted By: Warstud
maybe it needs a valve adjustment.

+1 This^^^ Im guessing it has never had a valve adjustment?


I totally agree. If an OHV, you can easily adjust.

 

[threeputtpar]

Originally Posted By: bubbatime
Originally Posted By: threeputtpar
I finally knocked the gap down on the plug from .030" to .020" which was the lowest available measurement on the coin gap gage. Since then, I've only had to pull more than once when hot to get it to restart. Problem solved.


Coil on the way out. Problem TEMPORARILY solved.


Thanks for the heads up on that. It makes sense that it would start fine when cold and the plug set to the correct gap, but not start when hot. But wouldn't a coil going out also cause performance issues even after the engine restarts hot, like low power or just quitting for no reason? Even at .030", once it did restart it would run 100% for as long as I needed without issue.