Are there any recommendations for a manual or book that describes the inns and outs of engine conversions for RC applications? Obviously there are repair manuals for weedwackers etc. but those have limited use in providing a practical understanding of what needs to be done to actually go from string trimmer to a flying two stroker.

Posts in this forum are of course useful, but having a reference all in one place would be ideal.

Thanks,

Well, after playing with these things for a few years, besides being a mechanic on all sorts of things all my life, I probably could write a book, but I just don't have the time.

I do remember my first one. It was kinda like "well, I'll just cut everything off that doesn't look like a model airplane engine and go for it!!"

Lots of talent and info here in the forum, ask away....

AV8TOR

Sent ya a PM.What ever ya need to know its all here in these forums.One good thread is the (dont forget echo),av8tor and i are in there along with bme and a lot of other greats from this forum.I think theres a couple long ones on homlite 25,ryobi31,maybe poulan.Jagengines has a step by step for the ryobis.Plus parts for (doityourselfers).wackerengines and carrprecision sell kits also.Thats all i can think of for right now.Ya got any questions just post them here in your thread.Heres a pic of one of my echos and a stihl,both weedie engines.

AV8TOR & buck1856,

Thanks for the encouragement. There are a few candidates for conversion lingering in my garage [Homelite]. At this time I am just planning on future projects and am in the information gathering phase. This forum provides a wealth of information for initiated & uninitiated alike, so for the time being I'll make hard copies of some of the various threads for future reference. If specific questions come up, I'll start a new thread or add on to this one.

Thanks,

Homelites in general work pretty well, and there is quite a bit about them here in the forum.

Good luck,
AV8TOR

Has anyone tried cross-drilling the vacuum port on the Walbro carb (Poulan engine) to line up the vac port on the engine....eliminating the plastic spacer and moving the mixure needles and throttle crank to the rear?

I think I can drill a port connection (tunnel) to a new, properly located port on the carb base, and plug the original one with an aluminum AN rivet or a dab of the famous JB.

Also, looked even easier to make a new port in the pump cover plate, and place a nipple on the crankcase, for an alternative approach?

The butterfly rubs the intake port, so a slight releif must be made with the dremel carbide.

I decided I'm not going to run it anymore until this is accomplished, the mixture needles are suicidal in the present form, and that chunk-o-plastic ugly spacer has to go.

What is commonly done with the intake manifold it to make a new manifold that rotates the Carb.

2 holes are drilled that mount the manifold to the engine and 2 more holes are drilled and taped
so the Carb. can be mounted to the manifold.

On the pupm cover there is a raised piece with a dimple in it.
drill and tap it there for a new pulse line. You can actually drill and tap the new manifold and and attach the pulse line there.

Ralph, Thanks for the reply, is thermal insulation required in this application?

Required I don't know for sure but it is a good Idea.

I can't remember what the stuff is called right now.
I'm running on about 3 hours sleep and the brain is fuzzy.

It's something ... board.

Ah someone will chime in here any minute with the right answer.

After I push enter I may even remember....

Poly board? Cutting board? I found that rotating the carb position 90degrees with a temporary dowell connecting the vac ports, two undrilled
pads appear to drill and tap, this positions the mixture screws aft and 45 degrees up, I'll just use a thicker gasket.

If you don't isolate the carb from the engine heat, you will have problems with hot restarts. If you let it cool down a while between sessions, it might be ok.

AV8TOR

Heres a pic of one of my first rotator attemps(works).drilled a hole halfway through board then cross drilled so nipple would be out of evrythings way.Aluminum base plate is bolted to cylinder with counter sunk screws.Then carb bolts are run through carb and board and into the aluminum plate wich is threaded.heres a few names for the board:
Delrin
Acetal
epoxy board
phenolic resin
phenolic laminate
G10/FR4
Arboron
Micarta
Do a search and you should come up with a lot of Distributers.You can also use round stock,not just square stock.