Hard starting B&S Quantum 6.5HP

[pezzy669]

So recently aquired a ~7 month old Troy Build TruCut 100 for $50. Excellent lawnmower BTW. Lawnmower had never been serviced. Oil level was slightly high, it started on the first pull but once in use about 5 minutes or so it would occasionally miss. The lawnmower did sit for about 2 months with no gas in the tank before we purchased it.

So I changed the oil and refilled with Mobil 1 T&S 5W-40/splash of Mobil Clean 5000 to top up and replaced the paper air filter. Now the lawnmower starts fine from cold with a puff of smoke but once hot it takes 4-5 pulls to get going. It no longer misses during operation like before.

Other then that it runs just fine. Its quiet and has plenty of power, does not even lose power through thick patches of grass.

Any ideas?

 

[Quest]

carburettor needs adjustment. Get a manual for B&S and do an adjustment. Can't recall if this is the nylon carb or the one with a rubber bulb for cold start priming but nonetheless, it has something to do with carb adjustment.

 

[Propflux01]

Sounds like it is running slightly rich. hence the hard starting hot, and the slight oil cloud on a cold start up from excess gas washing oil off of the cyl walls.

 

[80caprice]

This carb has no adjustments... should be a float type carb as well, make sure the gasket inbetween the carb and the air filter isn't squished out. If they are squished out, torn or undertightened.... it'll be hard to start.

 

[Chispas]

"once hot it takes 4-5 pulls to get going" is

common....

I asked my local service expert why? ....

He said, "Coils get hot, don't put out as many

volts as when cold."....

So, I just pull harder, spin the magneto

faster, this seems to help....

 

[CBDFrontier06]

I had a Craftman that started on the first pull every time when cold, but after hot, it got to where it woudln't start at all....until I tried closing the throttle almost all the way, pulling, and opening the throttle when it started to fire. Mechanic advised that it's running too rich.

 

[muddawgs]

try this.. i've seen this a few diff times on several 5 and 6.5 quantums. pull the square filter cover off and look through as you pump the primer bulb. you should see some fuel pump through. if you do not or it doesnt pump nicely or sounds like air then remove the rest of the plastic filter assembly and inspect the fiber gasket on the back. these are known to not seal well or loose there seal after time on the quantum engines. you can make your own with gasket material,or carfully use a quick set rtv or buy another.