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8hp B&S Help

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mikesartfx
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2020/11/07 23:15:22 (permalink)
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8hp B&S Help



Hello all,
I got a restored snapper mower with an 8hp B&S engine from a friend 11 years ago. The mower was/is a bit of a Frankenstein, but looks great and always started with a bump of the key, or no more than 2 pulls to start. It always ran great until last fall. It was very hard to start and seemed to be flooding the carb. I waited til this summer to work on it. It has been harder to start each time this year. I fought for 3 hours last week to get it started. It finally started very low and slow (chugging). I adjusted the air-fuel mixtures, and it ran like a top and ran better than it had in a year. 
I had rebuilt and cleaned the carb, (it has a 1 piece flojet carb), new plug, cleaned and gapped the magneto, replaced the alt wire which had burned through from the muffler, and anything else I could think of.
The engine uses a little oil, but doesn't visually burn any that I've ever seen.The engine has great spark, it just seems the combustion chamber isn't getting gas even though the carb gets plenty.
The fan key was even in place, I thought it jumped time...
Today I rebuilt the carb 2 different times and it would not start and the battery finally died.
I'm sorry I don't have pics, but I can get some posted...if I want to look at that mower ever again!
 
I am at a complete loss on this. Does anyone have any idea on what could have happened?
I know these engines are pretty common and hope someone has a clue.
Can the valves cause this?
I did remove the pull start, after it messed up last fall. I put in a new battery and it seemed to have plenty of power to start. It just was hard to start.
 
Thank you,
Mike

It looks like
Model: 093707
Type: 0936. 01
Code: 8640101

But I am not completely sure because I am not familiar with how B&S numbers these engines.
post edited by mikesartfx - 2020/11/08 15:55:59

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5 Replies Related Threads

    Roy
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    Re: 8hp B&S Help 2020/11/08 11:41:15 (permalink)
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    Welcome! Can you give us the numbers from the engine shroud? That will give us a much better idea of what you are looking at. If an old L head remove the cylinder head and inspect the mating surface, the gasket may be leaking. Clean the carbon and check the top of the cylinder for a ridge.
    AVB
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    Re: 8hp B&S Help 2020/11/08 14:51:23 (permalink)
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    With the engine having a flojet I would suspect it is a L-Head. With this old I would also suspect valve clearance has closed up on the old L-Head causing a loss of compression.
     
    Just a thought.
    Roy
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    Re: 8hp B&S Help 2020/11/08 21:45:20 (permalink)
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    I think the number should read 193707-0369. Never the less you have the old valve in block
    mikesartfx
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    Re: 8hp B&S Help 2020/11/19 08:50:37 (permalink)
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    Is this an issue I can fix/help by removing the head and cleaning out all the carbon, or do I need to go deeper?
    I do have a newer 10.5hp B&S on another mower I could swap. Or fix up the other mower...? 
    Thanks
    Roy
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    Re: 8hp B&S Help 2020/11/19 12:22:04 (permalink)
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    The head gasket is an easy fix, decarbon wiyh a plastic scraper while you are at it. Servicing the valves while not difficult is more involved and requires tools you may not have. Repair manual 270962 is your friend.
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