Briggs 17.5 opposed twin will not restart when hot 42A707

[troy-built]

Not some thing I wouldhave thought about with a mower, but the same applies spin at 1000 rpm and get a spark, spin at 400 rpm cranking speed and no stark.

You are exactly correct. The battery needs to be fully charged I have also found out.

 

[Scrubcadet10]

You didn't take any "heat shielding" off the cylinder heads did you?

 

[troy-built]

You didn't take any "heat shielding" off the cylinder heads did you?

Yes I did and it helped. Why shouldn't I have done that? To me it was just keeping the heat in. And yes I know the shielding helps the fan blow air across the fins. But when you turn the motor off they just hold heat in.

A little back info on this mower. I use it to pull a little trailer only the mowing deck is off of it so it doesn't run for hours at a time anymore.

 

[troy-built]

WOW 6K views of this thread. Hard starting must be a bigger problem than I thought.

 

[troy-built]

You didn't take any "heat shielding" off the cylinder heads did you?

Yep, As far as taking the heat shielding off. I did an experiment, I ran the mower around for 15 min to make sure it was totally hot. I checked the temp of the heads with the shielding off and then I put the shielding back on. I turned the mower off with and without the shielding. I checked the temp of the heads. The heads were the same temp both times when the mower turned off. Then I checked them 15 min later with and without. The heads without the shielding was 25 degrees cooler than the ones with the shielding. So the shielding does hold the heat in just as I thought.
This mower blows so much air when running it blows leaves when I'm riding through the yard. So I'm not worried about it over heating I'm just glad it's starting every time now.

 

[Scrubcadet10]

Wow, interesting to find out...

 

[troy-built]

Wow, interesting to find out...

I thought so myself.

 

[troy-built]

Yep that's where I often find mine.

 

[troy-built]

Ok I have an update. I've been running and using my mower a lot lately. Still from time to time it wouldn't start if it was hot and I have turned it off and on several times. I have found that if the battery isn't fully charged that would keep it from spinning fast enough to start it. But if I would let it cool off just a little lets say 15 min it would start right up.

 

[troy-built]

Yesterday I changed my 4 screw nikki carb to a 3 screw because it has more adjustments. What a difference it made, It runs and start like a totally different motor. I believe now it was getting to much fuel and that had a lot to do with it not starting properly. One thing it did before was backfire almost every time I turned the motor off when it was hot. That was caused by to much fuel on the hot piston I believe.

This has been a long process but I believe it is fixed now.

Hope this will help others.