GV150 HR21 honda 1978 mower shuts down - HELP!!

[Greggbegood]

I have a GV150 HR21 Honda 1978 that was my deceased father in laws that my son and I would love to resurrect. It runs great.....for five minutes! After five minutes or so, it just stops. I was lead to believe it might be the CDI ignition coil. They are hard to find, but we finally did find one. Although also from a GV150 HR21 mower, on the spark plug cord it said "-1" as opposed to the original one that said "+2." (Could someone explain this to me?). Regardless, when I put the new used one on, no help, same problem. Runs great for five minutes, then it stops running. If I go out 10 minutes later, ya baby, it starts and runs....you guessed it, for five minutes. So something must be overheating, then shutting down, then after cooling, it can run again.

So HELP! We wanna make grandpa in heaven proud. What is our problem?

Thanks. Gregg

 

[robert@honda]

I have a GV150 HR21 Honda 1978 that was my deceased father in laws that my son and I would love to resurrect. It runs great.....for five minutes! After five minutes or so, it just stops. I was lead to believe it might be the CDI ignition coil. They are hard to find, but we finally did find one. Although also from a GV150 HR21 mower, on the spark plug cord it said "-1" as opposed to the original one that said "+2." (Could someone explain this to me?). Regardless, when I put the new used one on, no help, same problem. Runs great for five minutes, then it stops running. If I go out 10 minutes later, ya baby, it starts and runs....you guessed it, for five minutes. So something must be overheating, then shutting down, then after cooling, it can run again.

So HELP! We wanna make grandpa in heaven proud. What is our problem?

Thanks. Gregg

Vapor lock (gasoline boiling)? How hot is it outside? Are you actually mowing and pushing the mower around or just letting it sit for five minutes before it shuts down?

Hard to think two coils are both failing due to heat.

 

[Greggbegood]

It's been cool. Mid 70's to low 80's. If I am pushing or idling, same results with bot old and new CDI ignition coil.

If it's vapor lock, how can that be fixed?

This mower doesn't have a fuel pump, does it?

 

[robert@honda]

It's been cool. Mid 70's to low 80's. If I am pushing or idling, same results with bot old and new CDI ignition coil.

If it's vapor lock, how can that be fixed?

This mower doesn't have a fuel pump, does it?

Probably not vapor lock at those temps. No fuel pump on this engine; it is a simple gravity-feed design.

When it gets to the point where it shuts down, and won't start, do a spark test:
If no spark, then it is something with the plug, wire, or issue with the coil.
If spark is good, then it is likely to be fuel-related. Perhaps dirt/debris in carburetor, clogged air filter, decayed/old/stale fuel, clogged/restricted fuel line, etc.

 

[Greggbegood]

Thanks for the info. Need to check out that spark. Gas should be good, and air filter is clean, that much i know. When it stops, it has run about the same amount of time, each time. If it was a clogged carburetor or fuel line, I would think it would stop at various times. Just seems to me like something heats up and shuts it off.

 

[robert@honda]

Thanks for the info. Need to check out that spark. Gas should be good, and air filter is clean, that much i know. When it stops, it has run about the same amount of time, each time. If it was a clogged carburetor or fuel line, I would think it would stop at various times. Just seems to me like something heats up and shuts it off.

Yes, start with the basics: Confirm spark, ensure air and fresh fuel are properly entering the engine. These two areas are 90% of why a mower engine won't start or shuts down. It also follows the golden rule of repairs, e.g. Check The Easy Stuff First, or How I Learned To Beat the Flat-Rate Times :laughing:

 

[Jkdet67]

Just a thought...maybe need to check engine compression??