Chainsaw Repair

Chain - Grinders - Filing - Wood Milling - Tools - Welding - Machinist - Mowers - Tillers => RC Radio Control - other small engines => Topic started by: wudpirat on July 27, 2015, 03:17:22 pm

Title: Need a piston ring
Post by: wudpirat on July 27, 2015, 03:17:22 pm
As the guy that fixes chainsaws, I was elected to fix a R/C boat engine???     ???
I believe it's a Homelite 30cc weed wacker engine, modified for water cooling.

Enforcer Model Marine Engine.  Model  Pro-Mod 30..  s/n E30 P62698-6
Measurements taken from engine
Piston.  1.43"-  36.42mm
Ring.    1.503"- 38.19mm,   thick  0.057"   1.45mm  ( from a broken ring)
Cylinder    1.438"  36.54mm

I went to my local Homelite dealer. Found a ring, correct dia but only 0.025" thick.
Another dealer didn't even want to help, said it was over 30 yrs old and a waste of his time.

Any help would be appreciated, point me in the right direction.
Even considered another piston with thin rings. 
I would like to get that boat running as I owe the owner a big favor.
Title: Re: Need a piston ring
Post by: 660magnum on July 27, 2015, 04:40:44 pm
He probably has them in stock? Frank Bowman Farmington, NM

http://metrorcflying.com/piston-rings.htm
Title: Re: Need a piston ring
Post by: wudpirat on July 28, 2015, 03:33:49 pm
Many thanks, checked out his website and looks like a home run.
Didn't realise the piston was pinned for the ring.  This maybe the reason the ring got broken in the first place.
Now to contact Mr. Bowman and get a ring.
If I get this engine running,  Billy is gonna owe Me big time.
Thank you again, I'm half crazy trying to find a ring, and all I had todo was come to this site and ask.

FREDM, Oxford, CT
Title: Re: Need a piston ring
Post by: 660magnum on July 28, 2015, 04:24:58 pm
Frank Bowman is not always the easiest guy to communicate with.

If you don't get him on the phone - maybe a email and wait two or three days.

Making rings is not his day job.
Title: Re: Need a piston ring
Post by: EHP on July 28, 2015, 06:59:54 pm
just asking a question ok, what kind of rpms is this engine turning cause if its lots that thick of a ring will have a hard time staying together , thick rings donot like high rpms that is why most high rpm motors use a thin ring
Title: Re: Need a piston ring
Post by: 660magnum on July 28, 2015, 08:30:05 pm
With the Homelite 30 piston ported engine, the set up was done much like a chainsaw engine. It would have cylinder cut down. The piston would be crowned .020". It's a counter lever crank type engine so the crankcase is stuffed with either a plate or the back of the crankcase is cut down so there is .020" clearance between the crank pin and the the back plate. The squish is set to .020" to the cut down part of the piston. The early ones had a forged crankshaft.

They run about the same rpm's the good chainsaws do. Sometimes 20,000 with the thin rings
Title: Re: Need a piston ring
Post by: wudpirat on July 30, 2015, 02:14:01 pm
Got an email reply from Frank Bowman, he can supply the ring I need.
Now to find out how to pay, he don't do CC or Paypal, I will have to check to find out how he wants.
The engine was originally a 30cc Homelite weed wacker, with the cylinder fins removed and a water jacket fitted for cooling. It has a piped exhaust, so I don't know what RPM it runs.
If the ring can't hack it , a new thin ring piston will have to be fitted. No my job, I just want to get out of this and get it running.
I will keep you posted, just hope it don't turn into a can of worms.
Title: Re: Need a piston ring
Post by: aclarke on July 30, 2015, 09:48:11 pm
Did you try marine specialties?
Title: Re: Need a piston ring
Post by: wudpirat on August 01, 2015, 11:59:20 am
Checked their web site, seems they deal in big boats.
This engine is for a R/C model, about five feet long.
Mr. Bowman is familiar with the engine and can supply the ring.
The check is in the mail.
Title: Re: Need a piston ring
Post by: wudpirat on August 12, 2015, 03:33:07 pm
Happy, Happy, Joy, Joy.
The ring arrived in the post and it's a thing of beauty and a sight to behold.
Frank Bowman is a class act and a pleasure to do business with.
It arrived with a sheet of instructions on how to correctly assemble the ring on the piston.
I also received and email, six pages, of the engine rings he can provide. Most of which I'd never heard of.
Need a ring and can't find it?  Try Frank Bowman.
Special thanks to 660 Magnum for pointing me in the correct direction.
Now Billy the Logger owes me big time.
Title: Re: Need a piston ring
Post by: 660magnum on August 12, 2015, 07:03:29 pm
+1
Title: Re: Need a piston ring
Post by: wudpirat on December 03, 2015, 05:59:01 pm
Followed Mr. Bowman's instructions on installing the ring.  Had to grind the pin to half length to allow the ring to seat in the groove.
Got the engine to run but the water jacket was leaking, filling the boat.
Finally got the leaks pluged , Yamabond sealed it just fine.
The boat just flies over the water with a big rooster tail. Runing e10 93 oct. @40:1
My Son fell in luv with the boat, now we own it. He is into R/C boats and planes.
His Drone w/GoPro camera cost more than a new Husky 394, and I thought chain saws were expensive.
Title: Re: Need a piston ring
Post by: 660magnum on December 03, 2015, 07:48:08 pm
Frank Bowman quit on us about a month ago. I don't know of an alternative for rings?
Title: Re: Need a piston ring
Post by: wudpirat on December 25, 2015, 02:18:56 pm
Sorry to hear that, and just when I found a source for rings.
Story of my life, find a good deal and they close up shop after I leave.

Have to tell the boy to baby that ring, no over temps or straight gas. I don't know where to find a replacement.

Chainsaws are more fun anyway.  SG (sour grapes)