Hello Everyone,
My garbage man brought me a Mac trimmer today. It looks like a Kioritz engine. It is a Road Runner model. Has anyone seen one of these? It is well made and light weight.

Dave

Hi Dave!
Your right! It is a Kioritz. The ones with the squared clyinder like yours are the largest cc-wise and may be as big as 25cc. More likely over 22 anyway. I have never measured them. They seem to be well built little engines but there is quite a lot of differences in port sizes and bearing types between outwardly similar engines. Also not all are solid state ignition. They were used by several brands but most often are McCullochs...........farley9n

Hi Bob,
I broke out my measuring stick and came up with 21cc approximately. The exhust bridge and offset plug interferred with perfect measurements. Come to think of it my math might be slightly off also. Anyway it is a 21cc Mac. I wish that the flywheel wasn't so heavy. Another neat toy to tinker with sometime.

Dave

Don't know for sure, but Kioritz and Echo are pretty high dollar engines, I don't think McCulloch would buy from them to make weedeaters..McCullochs were made here in Lake Havasu City, Arizona before they went bankrupt...Harbor Freight bought some of the finished ones and 2 guys here in Flagstaff but tractor trailer loads of unfinished stuff....I think the name went to China, like SuperTigre.....
A Koritz should have the Echo symbol, a stylized "E" somewhere on the case or cylinder...Looks like 3 small Christmas trees on their sides to form the "E"...

Here, McCulloch has some relationship with Electrolux.

I have several of these and they are 18-21cc . They make decent power for the weight if you use electronic ignition and do away with the mag .

Dave,after reading this post i went and looked at my engine i pulled from an eager beaver by mac.its 18cc.as seen in the pic it weighs 38oz.im going to try a tim6 on it.it was a points engine anyway.you can just barley make out the E on the side of the cylinder under the lower exhaust bolt.the muffler came from ken lambert.

Buck
I think yours is an echo it has round cylinder fins the macs have square cylinder fins and a different carb adapter but the same muffler setup

Buck,
The case is the same as mine, but from what I can see of the cylinder it is round rather then square. Mine has a single pinned unpinned ring and stamped aluminum rod. Kioritz just increaes the cylinder bore size to create the different displacements from 21 to 25. The port timing on mine is very conservative. Intake=55 degrees BTDC,Exhust=60 degrees BBDC,Transfer=45 degrees BBDC. Yours ought be a great gasser for small planes.

Dave

i looked at my case and cylinder and it has the echo(E) shaped x-mas trees like ralph said.i just printed the timing circle and port data from a thread here on rcu.it looks pretty easy to figure out.im going to look at my scrap mans pile of weedies a little bit better in the next few days.he has a metal scrap buisness and has quite a few macs laying around.plus a lot of others.thanks for the reply ken. i figured it was an echo but the E proved it.your muffler looks great on it.one thing nice about these engines the carb is already straight shot from the start.i have the tim6 but im going to get a different hall sensor that doesnt have the angle on it.mine has the bridge in the exhaust,single ring and stamped aluminum rod.

Guys, I've got two similar engines - one from a trimmer and one from a leaf vac. My leaf vac engine model number is 400048-06, and I heard from a guy in Australia that these were 18cc engines. But I couldn't find conversion parts for these - only for larger McCullochs. I'd like to end up with something like that in Buck's pictures - can anyone steer me to conversion plans or techniques and supplies? What do you do with the part of the crank that extends out the back of the case? (The McCulloch conversions I did find didn't have the crank extended out the back.) Now I'm not extremely engine smart but I'm pretty handy, so I'm confident I could convert one of the engines I have. Any info and advice you give would be appreciated.
Thanks in advance,
Bidwin

HI Bidwin,
Pete at Wackerengines.com can male the prop hub for you. My Mac has a 8x1.25mm shaft, but yours may be different. Take the nut to the hardware store and match it up to get the size. The rear shaft can be cut off with a cutoff disk on a dremel tool. You can bolt the engine to the firewall with the existing mount. Use metric screws with large washers. Or make a plate from 1/8th to 3/32 aluminum. The engin may come out heavy because of the flywheel etc. Think about gas with glow ignition discussed in another thread. Wacker has glow adapters also.

Dave

Thanks for the reply, Dave. I was planning to ditch the flywheel and add an ignition system such as CH's. (Matter of fact I talked to someone at CH about my engines but he couldn't help too much since they don't see or work on any like mine. I guess I could go buy another engine that's more easily converted but what's the fun in that??) So for me that begs the questions about where I could get all the parts I need for the new ignition and how pickup would be mounted to trigger the spark, and how much of the case can I trim to lighten the load without compromising it. I'll check with Pete at Wacker for some of this. I know I could search but, to be honest, it's much quicker to ask questions, so can you point me to some info that discusses or shows in pictures how to do a conversion step-by-step?
Thanks again,
Bidwin

bidwin,if youd like,send me a pm with your email address and ill send you some pics of my setup and of different hubs with the pickup magnet installed.one pic is worth a thousand words is what ive been told.these will help.
ken lambert from above post----homemade mufflers.(the one on my engine above).
pete at wacker engines---hubs,carbs,mounts.
john @[email protected]
ralph------rcignitions----mounts,ignitions,ect..
chignitions------all ignition systems use the same basic parts and are installed basiclly the same way.
check the threads here for a lot of info and pics.one thread(dont forget echo).the people listed above are people ive purchased items from and email.them.theres a lot more though.

I also have MAC that I don't know the size - I've done some conversion work but maybe it's all a waste of time. Attached are pics of the engine and it has Needle brearings? Does that condem it for junk or can it be saved. I need a layman's explanation of the negatives of having needle bearings. Are they bad even if the crank is supported on two sides with bearings?
Sides7[img][/img][img][/img]

it is either a 28 or 32cc and roller bearings are best needle bearings arn't all that good i have amuffler that fits these useing the stock spring .

Ken
My mistake. I have edited my post to say NEEDLE Bearings, Not Roller Bearings. Now what's the answer, Please?
Sides7

needle bearings will work ok they do not hold up as good as roller bearings but work fine . Some of the quadra and such has had needle bearings and last years without much problem .

Hi!
I've seen a lot of those McCullochs and have yet to see one of the 28-32cc ones as pictured with anything but ball bearings on the crankshaft and needle bearings on the rod and pin. While i'm at it I have also yet to see one of those early style Mac's from kioritz to have anything but a forged steel rod. Only the late non-kioritz engines with out the fullly supported crank have the aluminum rod.......... farley9n

Bob,your right again.i looked at my rod closer and tried to scrape it still in the engine and it is steel.things just keep loking better for these little engines.let me know when you get a poulan 46 thats worth converting.bare bones with carb and muffler only.(mufflers not that important).