Engine information
 

Anyone know what engine this is and what are your thoughts on the condition? I believe it to be a 30cc Homelite. The rings are pinned so I will get a bowman ring. Do I need to get two rings or just the top ring? Also the top if the piston has a nick on it. Will this affect operation and is their a way of sanding it? A bit of carbon on the top of the piston as well.

Thanks

All in all probably a useable engine, but it's worn. I don't believe it is "virgin". The sideways sanding/score marks in the cylinder were made by someone with too coarse a grit sandpaper. The base gasket does not appear stock, and it is covering portions of the transfer port passages, and the transfer ports appear to be the small ones. The piston is worn. Normally I use a Bowman ring in the top groove only, and a stock ring in the second groove. It appears to me that a piece of the second ring is broken off right where it is supposed to fit over the pin in the piston on this one. If the top ring is undamaged, just use it in the second groove.

The engine can be rebuilt and will run, but it is not the best candidate for an engine you are going to put a lot of time into souping up due to the wear on the piston and condition of the cylinder. It is a 30cc. The fastest, easiest way to tell a 25cc from a 30cc Homelite it to just look into the exhaust port. The 25cc has the bridge in the exhaust port while the 30cc does not.

So I have a 11mm carb, Would this engine be a good for this carb? What can I do to get this engine a good runner?

I would clean everything up real well. Take some 400 grit sandpaper used with solvent and lightly sand the cylinder bore. Then put the top ring in the second groove, a Frank Bowman ring in the top groove, install a new base gasket and you should be good to go. An 11mm carb will work fine.

It is not worn enough that it won't make a good running, use-able engine. I would just choose one in slightly better condition to use as a base for an extensive hop up project.

AV8TOR

Sand the bore up and down like the piston would travel? What solvent? Anything with the piston?

Lightly clean the piston with some Scotchbrite and soap and water. Sand the bore in a circular motion opposite to the way the piston moves. Use any solvent, such as mineral spirits, kerosene, diesel fuel, (stinky), even some WD-40 would be better than nothing. Some oven cleaner will help with the carbon in the head, but don't let it soak too long.

AV8TOR

Thanks. Their is a nick in the top of the piston with a piece of the piston sticking up slightly. Can this be repaired or is the piston junk? Sanded flush?

Carefully cut the raised metal off with a sharp knife, then gently file or sand the area smooth. It shouldn't hurt a thing from what I can see of the pictures. I sometimes grind the piston in certain engines half way down to the ring groove in the area of the exhaust port. There's material to work with on the piston top.

AV8TOR

I looked at the back plate and not much room for stuffing the crankcase. Any other ways of increasing compression? Leaving off the jug/block gasket to achieve .020

Clean the cylinder base and crankcase very well. Then bolt the cylinder on without a gasket. If the piston to head clearance then measures .020" or close to it, then just final assemble the engine with some Yamabond or other case sealing product and leave the gasket out.

AV8TOR

Thanks, What are your thoughts on the intake and exhaust timing for this engine?

Pick up a glaze breaker at your local auto parts store and run that thru the cylinder just enough to say it looks good. Kerosene would do for a lube while using the glaze breaker. Keeps the stones from loading up and allows for a clean job. Be sure to rinse completely after this work.

why not just buy a new engine

Depending on the bore diameter, a brake cylinder hone may be better sized.

Regards, Richard

Junk... Pitch the top end. Look at. the wear patterns. The piston skirt is well worn and it has caused some wear in the jug. Most two strokes that die for causes other than melting down die because the piston wears, it starts rocking in the bore, then breaks the skirt off then boom.... Hint is all of those machining grooves you can see in the piston near the rod.... Guess what on a new piston you will see those run all the way around all nice and even... They actually help hold the oil film for lubrication and reduce drag. Notice how near the ring they are all still there but as you move down the piston, they dissapear. You can see the wear the rocking has caused in the jug.. you would probably need to go well over .030 on a bore to get it round... Dont waste money on a new ring, it will just get you to the end sooner. Find another in better condition for your final product and use this one to learn on...

So this engine is not worth the time or effort to get to run? Can anyone help with part's for this engine?

Buy that Kawasaki 50cc I offered you. It doesn't weigh much more, and will put out so much more thrust it will scare you, and no modifications needed.... Just bolt it on and run it. You'd probably be the king of the airboat scene there.

AV8TOR

I need to stay in the 25 to 30 cc range for the hull I built. I would really like to get this engine going to put on the hull. After all, I did purchase this engine here on rcu from a well know engine builder. Any help would be appreciated.

I'd be going back to the seller asking for a refund or something and using a different powerplant. Given the wear shown on the piston, I'd tend to agree with not doing a lot of work to this engine. It'll run I'm sure, but if the piston and cylinder are worn, ring sealing will suffer even if using new rings.

I have a Homelite 30cc engine laying around myself but I'm unsure of its condition internally. It appears to be low runtime and came off a weed trimmer. Has a Zama carb on it.

Interested in selling the engine?

Could I use a piston from another engine? If so What type of engine and how do I measure if needed?

I get the idea these Homelite engines are not made very well. My low time engine looks pretty worn. Here's some pictures of the piston.

That looks just about the shape mine is in. What are you planning for this engine?

I was going to originally strip it down and convert it to glow plug ignition and glow fuel and put it on something. Thought about modifying the clutch and putting it on a bicycle. I have no interest in putting it on a plane - don't care for anything that big.

Go take a look around on Daves for some good information & parts. Plus new short blocks.

http://www.davesmotors.com/Products/Complete-Engines/