Surging When Hot - Replaced Carb, Plug, Coil, Air Filter - Video & Pictures

G

glawnboathead

Forum Newbie
Hi Folks.

So when my Lawnboy model #10627 gets hot it starts surging. Here is a video of it.

[video]http://vid1114.photobucket.com/albums/k526/GmanBanjo/MVI_5880.mp4[/video]

Here are some pictures of it.
IMG_5881.jpg

IMG_5882.jpg

IMG_5883.jpg


I have replaced the carburator, have good fuel, and good fuel flow.

I have replaced the coil and plug and air filter.

I have tried running it with the gas cap very loose (so no vacuum).

Suggestions? Could it be a auto choke?

Thanks for your advice.
 
bertsmobile1 said:
If it only surges after it gets hot then you are chasing an air leak between the carb and the cylinder.
Click to expand...

OK. I will look into that. I did put a new seal on between carb and motor when I replaced the carb. Things did improve somewhat with some of these new parts. It used to not even start after stalling when hot. Now it keeps running until it hits a load, dies, but is easy to start.

Squirt some soap water around the carb to find the leak?
 
carb cleaner, something that is going to change rpm when it gets into engine, brake cleaner would also work.
 
Hi:

Is your float height set the correct amount? It may be a bit too low!

This sounds like a fuel problem. I had a similar problem with a 4 cycle engine. I replaced the carb with a new one, but the problem remained. I called the factory and their expert told me to drill the main jet with a certain letter drill. End of problem! Both carbs were made with the main jet too small.

Call LB and speak to a tech! Your surging sounds like it is too often to be a fuel problem. Usually a surging problem is not that rapid. Could it be something in the spark advance? I had a problem with the spark advance in a LB two stroke engine that caused the engine not to speed up to running speed after starting. It started easily but would not rev up to full speed. I found that the automatic spark advance was faulty. Replaced ignition module, $24.00, and all was well.

Keep us posted as to what you find.

Good luck,

Franchi
 
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