B&S 7.75HP Snowblower Engine Seized

[ronbo]

Good News, Bad News

Engine turned over after 2 oz of MMO,overnight soak. Today tipped engine to check something some MMO came out , had spark plug lose in hole, tick off, put wrench on crankshaft nut and engine turned over. Drained engine of little oil and added 20 oz that was required. Overfill on dipstick about 1/8" ?

Went with it, started engine and it ran. Starting using it and after a while notice dripping oil. Turned off opened dipstick and positive pressure, went poof, like opening a soda bottle. Ran back to garage and notice power was very weak on return.

Thinking rings are gone? Imaging if I replace , will have to get a ring compressor tool to get piston into block?

I see some people advertise doing barn jobs on small engines.

Probably will try to do myself but might wait till spring.

 

[Quest]

compression rings worn/not building pressure due to previously running with no oil.

Cylinder wall scuffed.

excessive blow-by and lack of compression as a result.

This is one serious rebuild job and it's best to source another replacement engine instead (it's toasted).

Q.

 

[JTK]

Ron- if the oil was overfull, it will build excessive crankcase pressure just from that. Overfull will cause power loss as well. Given it starts, runs and doesn't smoke like an old diesel, you might be fine.

 

[ronbo]

Originally Posted By: JTK
Ron- if the oil was overfull, it will build excessive crankcase pressure just from that. Overfull will cause power loss as well. Given it starts, runs and doesn't smoke like an old diesel, you might be fine.


Thanks for your reply.

Yes, I'll check the oil level tomorrow, if over, I'll drain. Wished I did it right away and went right to the FULL mark. Then I'll re-start and run in place.

Checked piston ring price and about $30. If no go, might go will the HF 6.5 engine for $119 less coupon.

I did find the engine has two oil fills, one in yellow that's OK and one in black that blew off. Figure B&S did it this way to depend on the application.

B&D online engine owner manual claims to use lower fill, fill 20oz to overflow, to use dipstick or high fill, keep on checking dipstick. I did high fill. Ticks me off I didn't do it right.

The one way trip to the front of house was OK blower worked good. The return was bad and I hate to drip oil on the property.

 

[ronbo]

Originally Posted By: Quest
compression rings worn/not building pressure due to previously running with no oil.

Cylinder wall scuffed.

excessive blow-by and lack of compression as a result.

This is one serious rebuild job and it's best to source another replacement engine instead (it's toasted).

Q.


Thanks for the reply.
Will check oil tomorrow, mark sure it not pass FULL, run in place and see what happens. If no, go, it's to HF for replacement.

 

[ronbo]

UPDATE

Check oil level, OK, between 1/2 way between full/empty. Started OK, idle awhile, open dipstick, proof, had blow by. a positive pressure. When increased speed, then noticed oil drip.

No surprised after running with, no oil, engine toast. Just rings are $30.

Will wait for better days, to work outside garage to remove engine and check to see if the 6.5 HF Predator will fit.

my machine, engine B&S 7.75HP,
mdl# 12C414-0131-E1, think shaft 3/4"X2.56", HF engine 3/4''X2.43, have the HF mounting
hole diagram, will check mine out.

Thanks for everyone's help, I'll post results as it happens.

 

[ronbo]

Ordered the B&S 7.75HP engine and installed yesterday. Job went fairly easy , since engine is the same. Noticed the electric start is to the side an improvement to the original where it was in the back.

The engine was well packed with foam surrounding it. Notice the shaft was rusty? (assuming from storage, sitting on shelf} so wiped down with Kroil.
Weird that ground bolt on original was 3/8" head and replacement had to use a 10mm to get bolt off. Used the SAE stuff from original on replacement with no problem.

Will start for first time today and see what happens.

 

[ronbo]

Yes, I installed engine one day, filled with oil since it came empty. Also checked the one on each side oil fill plugs. They were both loose, esp the right hand side one that blew off on my original engine.

Then I put index marks on the oil fill plugs so I can check if they loosen.

Gave myself until the next day until I started engine, give my brain a chance to think things over.

Gas it up, primed three times and installed electric starter plug. One push of the button and it started. Ran it up/down the driveway and I'm good to go.

The engine total cost with shipping was $317.05, delivered to my door. The engine came from the Maryland warehouse, the main store of Jack's.

I needed a 3/4" , 2 9/16" shaft and this OEM original meet the requirement.

Now, I'll see if I can part out the good parts on the bad engine.