Engine is fighting compression when I try to start it.

elogger

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  • / Engine is fighting compression when I try to start it.
I thought it was the compression release on the camshaft so I pulled the engine off the lawnmower and checked the camshaft and everything was ok. I put the engine back together and turned it over a few times with the spark plug out. Then put the spark plug back in and turned the key to start and it will not turn over. I though maybe it was vapor locked so I pulled the spark plug and cracked the engine and only a small amount of vapor came out to the cylinder. I purchased the engine new in March it is a briggs & stratton 19 hp 33S877-0019-G1. I checked with authorized service dealers and they can't get to it for months (I need it NOW).

Any help would be appreciated.
 

r1100ron

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  • / Engine is fighting compression when I try to start it.
I thought it was the compression release on the camshaft so I pulled the engine off the lawnmower and checked the camshaft and everything was ok. I put the engine back together and turned it over a few times with the spark plug out. Then put the spark plug back in and turned the key to start and it will not turn over. I though maybe it was vapor locked so I pulled the spark plug and cracked the engine and only a small amount of vapor came out to the cylinder. I purchased the engine new in March it is a briggs & stratton 19 hp 33S877-0019-G1. I checked with authorized service dealers and they can't get to it for months (I need it NOW).

Any help would be appreciated.
Have you checked the valve clearance?
 

slomo

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  • / Engine is fighting compression when I try to start it.
Is this a repower or what?

New in March engine I get it. Is the mower new in March too?

Also sounds like you need a spare mower. Don't know how I could make it with only one mower LOL. If I get below 5 I get nervous.
 

Tiger Small Engine

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  • / Engine is fighting compression when I try to start it.
Is this a repower or what?

New in March engine I get it. Is the mower new in March too?

Also sounds like you need a spare mower. Don't know how I could make it with only one mower LOL. If I get below 5 I get nervous.
If you knew enough to pull the engine, split the case, check the camshaft and compression release on the camshaft, and reassemble, you should have known about checking valves first. Pull valve cover, manually rotate engine and watch for very subtle movement on intake or exhaust valves (depends on engine). That is the compression release “bump”. While you are in there, set valves.004” intake and .006” exhaust at 1/4” past top dead center on compression stroke.
 
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