HS50 bottom dead center issue?

[ugmold]

I did another post on this engine but hopefully can be more specific here. When my HS50 hits bottom dead center there is considerable movemnt of the crank before the piston moves again, the result is hard to pull start and breaking keys.

The bottom dead center issue is shown here, cue'd up on the video.

 

[Skipp]

I think I’d drop a little oil down the cylinder…sounds tight what’s your ring gap

 

[Skipp]

I bought an engine that was”professionally” rebuilt….guy went by parts tree and the motor numbers to order parts…he was wrong…did you measure cylinder etc to
Make sure correct piston etc…not trying to be a smart ass…but that motor was tight I couldn’t pull it…got correct parts and work as supposed to

 

[mustangfrank]

Yeah, you have a tight cylinder/piston/rings situation and guessing a loose/worn con rod or piston pin.

I wish you wouldn't have bailed on lapping the crank and flywheel.

Did you find an older Sears Tecumseh cross reference to figure out the exact engine designation? If it came off that snowblower it is an HS40 based on the snowblower model number.

Get yourself some Plasti-gauge, measuring tools and a cooler full of beer or hit the classifieds and find another RUNNING snowblower to rob the engine.

 

[Mark Brooks]

Does a tiller count? That requires Beer right?

 

[massacre]

I had a similar issue with an HS50 I built.
Turns out the rings were in the correct parts box with correct number
but were not the correct rings.
Had to reorder the rings and measure the end gap. Then it worked fine.

BTW I have always used valve grinding compound to lap flywheels and never had a problem

 

[ugmold]

I covered ring gap, which is ok, and other issues in my first post that went dead.
https://oldminibikes.com/forum/index.php?threads/hs40-piston-arrow-direction.173378/#post-1270224
I added time stamps to see those things and others I felt important.

I think "massacre" might be on to something. The guy I bought it from said he bought a new muffler and carb, didn't say anything about the rings and piston, but they look new-ish. Could be wrong.

I have a Craftsman/Tecumseh cross reference that list the number as a HS50, no other details. Jacks small engine says it is a HS50 as well. But funny, the kid I got it from said it was a 4hp and it was off a snowblower.

I wouldn't even consider this engine but there is a Minibike Race/Party coming up and needed a bigger engine for.

 

[Skipp]

According to the number provided in the first post your motor is hs50-67181c

 

[ugmold]

According to the number provided in the first post your motor is hs50-67181c

Thanks Skipp. That helps in the parts search, any idea of year?
I read another post by "massacre" about his fitment issues which do seem similar to mine, so I think I need to do some measuring and looking etc. I also see that there are thin and fat ring sets to add to the confusion.

Right now I am "borrowing" the camshaft and trying it in another "freebie-beauty" HS40 I picked up a couple of weeks ago with a snapped camshaft.

 

[cfh]

the "C" series HS50 is usually 1979ish.