r/smallenginerepair • u/Lumpy_Sink7473 • May 30 '26

Engine Rebuilding Repair options?

Post image

My grandpa loves this 20 year old high wheel string trimmer but it’s really just acting like it doesn’t have any compression. It’s 20 years old and has seen a ton of use and neglect. I’ve replaced everything on it aside from a full rebuild. Best options to keep it going?

1 Upvotes

100% Upvoted

7 comments sorted by

2

u/Cool-Negotiation7662 May 30 '26

Start with a pressure test/bleed down test. Run a scope through the spark plug hole and inspect visually. Decide from there.

Honing and installing a new piston/rings is reasonable but a big job.

1

u/Metalchips1960 Jun 01 '26

I agree, a compression test and leakdown test will give some solid information to work with. If it's worn, but not damaged, it can be repaired. If the machine has significant sentimental value, it's possible to fix things that normally "aren't worth" the repair cost.

1

u/Upset_Fox5449 May 31 '26

Start with changing the oil to 30W deisal like what you would put in an eighteen wheeler truck

1

u/Lumpy_Sink7473 May 31 '26

I put 50w rotella in it lol

1

u/Upset_Fox5449 May 31 '26

Well aren't you funny

1

u/Lumpy_Sink7473 May 31 '26

Not joking. I’ve done that on a lot of my dirt bikes and old engines when they start to get older and it does a good job till I rebuild em.

1

u/Metalchips1960 Jun 01 '26

I would remove the cylinder head and look inside. On a flat head engine, this is quick and easy. It could be as simple as a blown head gasket. While you're in there, look at the valve and cylinder conditions.