OK--here goes my first post. I have been flying and building for years but brand new on the gas conversions. I know some of the questions are probably answered here but could not find them. I have a weedwacker Homelite 30 cc. I hope to put it on a plane that is now 9 lbs with everything on it but this engine. It has a front plate behind the flywheel that is part of the lower case that holds the mag. # 1 Do most folks mill this plate off to lessen the weight if they are going CH-Ignition? When I pulled it down,the back plate that went into the crankcase was part of the plastic housing. #2 Can I make a cup type mount that will replace this and if I can will I need to make this with a plug that will go in the same depth that the plastic one was to keep the same case pressure or case atmospherics? Also What is the best model Walbro that would work on this engine? The venturi just don't look as big as the ones flying at my field. Any help or pointing me toward the right URL would help. I can upload a photo if it would help and thanks to the ones that has Probably seen these same questions a hundred times. ha. ha. Hooker53

Hi
Go to the sub forum Engine Conversion
Plenty of info and nice people ready to help.
Browse also the sub forum , the homelite are very common subject.
With the RCU help you have the success assured.
I am converted a Homelite 38 cc chainsaw engine, new, very easy to convert.
I am living in Argentina and the glow fuel need many hours at work to buy.
Happy landings
Jose

Hooker 53, I sent you a private message...........

Most of the conversions concerning the engine mount utilize a flate aluminum plate that bolts on over the existing rear cover. On this original rear cover, all the plastic is cut away even with the outer edge of the engine block. Warehouse hobbies and other boat people make a complete combination rear cover and mount that is actually made for boats and the mounting portion would have to be modified.

The best model of Walbro is the WA167A with a 7/16" bore. There maybe a used one that has a 7/16" bore that you may be able to obtain locally used a little cheaper? Don't go beyond a 1/2" bore.

The C-H will not give you any noticable amount of increased power but it will save you a little weight. All the 25's & 30's I've seen including my two have the original magneto ignition. The excess part of the plate behind the flywheel is removed. I have C-H on my McColluch conversions though.

The engine is going to weigh a little over 3 lbs.

Enjoy,

Jim

Thanks Jim for the reply. Even after I put it in the wrong forum. Ha. Ha. I know--After buying the CH- Ignition I read here that there is no advantage to it other than a few less ounces. The biggest thing I was looking for in the CH- Mod was easyer starting and the timing auto advance. I will be on the lookout for the Mod. Walbro that you mentioned. The first one I see that I can get I will do so. So the way I see it now, you keep the cup/cover and the outer edge of it and you sandwich the plug portion of the old cover in between the case and the new plate mount. Wouldn't this cause a soft mushy kind of mount?? I guess mabey not enough to hurt. Thanks to all that answered me and Have a very good christmas. Hooker 53

You will have a hard time getting Terry to want to sell you a synchro-spark for a Homelite 30. Normally it is a waste of money for the synchro version unless you are running a domed piston with a .020 squish band. It's just a waste of money on any weedie that has not be radically modified internally. The main reason for the variable timing version is to prevent kick back when starting and the Homie weed whacker engines are not noted for doing this with a standard combustion chamber and timing.

Your assumptions about the backplate are correct. The plate is not soft enough to present much of a problem. Some Homelites have metal back plates. You can order a metal one from the chain saw dealer if you like.

The cheapest place to get your carb is from the usual AD that's at the top of the conversion engines forum. They will sell you all the parts you need too. I think the carbs are take-offs but are unused. Naturally C-H will also sell you all the parts as well as Carr Precion and several other people that are set up commercially. There are also several people that are regulars on here that will make the parts for you.

Enjoy,

Jim

Except my very first CH ignition module, all the rest have SynchroSpark auto advance (or should I say, auto retard ). I may not need it on every engine I have, but this way, the SynchroSpark is there if and when I need it. You never know, after I dork that Ryobi into the ground, I can always use the same module on a Poulan 46cc.

Besides, Synchrospark makes the engine idle down lower and smoother, which is important when you have a floater like a J-3 Cub that just wants to keep flying.

send it to carr precision. great work for a fair price.

Thanks all, for the good replies. Now to sum it up. After converting the Homelite 30 cc for all I can get out of her, Do you think it would pull my Sig Sukhoi SU-31 with any authority at all? The plane is coming in at about 9 lbs with everything in it less the engine? What prop combination would be a good try? Also----could anyone give me Frank Bowmans E-mail or web site?? I went thru 9 pages on google before I gave up. Thanks Hooker53

Frank Bowman
1211 N. Allen
Farmington, NM. 87401

[email protected]
(505) 327-0696

Be patient with Frank, he may sometimes be a little slow in responding to emails. As I understand it, he's "retired" and certainly deserves to enjoy life's other distractions. Most times I have corresponded with him via email, he has been very prompt and courteous. Super guy to deal with.

As for your SU-31, well..., my Homie 30cc on CH Synchrospark manages around 8500rpm with a 16x8 MA and weighs around 3 lbs 10 Oz. with an aluminum mounting plate and B&B muffler. This was after only 16 Oz. of gasoline run through it, so the engine is still very green. I am hoping to get over 9000rpm with the same 16x8 MA once it breaks in some more. This might help you draw your own conclusions.

Thanks Volfy, I got ahold of him today and you are right, he is very nice and a storehouse of info. I having been in the machine shop Biz for 35 years enjoyed talking alot with him. I'm really looking forward to getting this engine running. I have a WT-433 carb coming for it also. I'm just having to stop and think for awhile just what I can cut off of the case to lighten it and still not hurt it's integrity. I could get too carried away here if I don't watch it. Thanks again Hooker53

I left quite a bit of the flanges under the base of the cylinder untouched. The cylinder is held on with only 3 bolts, so I wanted to make sure the base of the cylinder stays rigid. Otherwise, I trimmed off the rest of the crankcase webbing as much as I can muster with my little 3" cut-off wheel. I wish I had a millling machine, but the air tools do an adequate, if not pretty, job. The crankcase only bears the load on the crankshaft bearings so there's plenty metal there even if you trim off all the webbings.