Why Does My 5 horse briggs flathead keep seizing???

[5horsebriggs]

well i jus rebuilt my 5hp flathead it now it seizing every 3 hours of use why is it doing this:shrug:
(edit)= the piston is gettin stuck in the sleeve and the sleeve is dri why isnt it getting oil

 

[Txpowdercoater]

a. ring end gap not sufficient for expansion with heat and or piston not sized correctly for bore
b. binding on crank bearing due to incorrect tolerances and or low or no oil.
c. all of the above
I dunno, any of those sound right?

 

[5horsebriggs]

every thing is stock on it thought and i ran it on the right oil

 

[Txpowdercoater]

every thing is stock on it thought and i ran it on the right oil

what did you do to the motor to "rebuild" it. what was put in it? honed?
new stock sized rings? check end gap and file appropriately?

I see you edited the original post and gave more info. the oil system is basically a slinger type, no pump, just slings oil all over as the crank and rod plows through it.. sleeve or cylinder may appear dry but it is what it is if you had correct amount of oil in it.

 

[5horsebriggs]

well i shoulnd say rebuild i just clean all the origanal parts and washed most of it down in oil but it ran good the past week then all of assuden it seized

 

[Txpowdercoater]

well i shoulnd say rebuild i just clean all the origanal parts and washed most of it down in oil but it ran good the past week then all of assuden it seized

hhhmmm, well, you dont know if its seizing on the crank or seizing in the bore. really no reason for it to swell and seize in the bore if its all the same parts it had and worked fine with.
check oil for metal shavings and if so suspect crank bearing is heating up and seizing. did the oil slinger get reinstalled on the rod? if so is it on correctly?
I always run 20wt oil, its light enough to get slung in and oil crank bearing etc etc etc

 

[5horsebriggs]

no i use 10w40 and it seemes to be seizin in the bore becae if i put oil into the bore it runs smoothly but i can spin the engine back words if it seized to unseiz it

 

[Txpowdercoater]

just for grins, check to make sure the rod cap is on correctly so the slinger if it has one is aimed correctly.
I cant see it seizing in the bore with all the same stuff it had, as in same rings etc etc.
run lighter oil but still, check crank.

 

[5horsebriggs]

the rod cap is were the oil slinger is?????right and use 10w30

 

[funky ole]

pull the side cover off and post a pic of the crankcase. lets see what it looks like in there.

 

[jim210]

Are you using a side cover gasket and do you have endplay? Over tightening the side cover bolts can cause an engine to seize.

 

[5horsebriggs]

well the piston will get stuck, but then if i take the spark plug out it doesnt seize any more

 

[jim210]

Maybe your sparkplug is wrong and to long. I've seen someone do that before

 

[oldfatguy]

are you sure that it is seizing from lack of oil ? If the piston seizes in the bore
you wouldn't be able to turn the engine over at all. If an engine is going to seize it will run real hot first and you will see the block smoking. Your problem could be something simple like the governor adjustment. I had a five horse than had the governor arm move far enough to bind up the engine

 

[5horsebriggs]

wel i can still move it aliitle bit so it might be the governor

 

[5horsebriggs]

now i walked out side pulled the cord and it started if i had too much oil in it would it make the engine get stuck

 

[bigrob]

:doah::doah::doah:

 

[5horsebriggs]

but will it

 

[125ccCrazy]

if i had too much oil in it would it make the engine get stuck

only if it's filled to the top of the head.:scared:... you have clearance issues somewhere.... the engine will have to come apart to inspect for the culprit...

 

[Neck]

Usually, once a piston seizes, the rings get fouled up with piston/cylinder scrapings and won't start due to too much blow by. You need to give us more of a description of whats taking place when it stops running like noises, slowing down before seizing etc.