I have a maccolloch weed wacker that I have that started to convert it untill I found out that it has needle bearings[:@] on the crank.can I keep going on it or throw it out? there is no thrust bearings on it. thanks Erik

Most conversion engines have needle bearings.

The size of the engine is the determing factor if it is worth converting.

What are you going to put it on?

I believe he is talking about the crankshaft main bearings, which should be ball bearings instead of needle bearings ideally. You could use a brass washer as a shim to take the thrust loads, but if it is a weed whacker engine, they are so easy to come by for free or very little money that I would suggest moving on to another engine.

AV8TOR

Could you post a picture of the engine your talking about? What cc motor is this? I have one I started on a day or two ago and if I'm wasting my time, I'll move on to a different motor. thanks for the help.

The McCulloch 28/32 was the one most commonly converted.

They had ball bearings on the mains and needle bearings on the connecting rod.

I have two 32's converted with C-H ignition and G-26 carbs

from looking at the engine I'll have to pass it on I don't think it will take the side load thanks for the help Erik

They are a bit gutless too. Tiny transfer ports. 16*8 about the biggest prop you want.

Mine's retired now, bless it

My 32's turn a 18-8 at 7600. That's not gutless

All of my quadra and US engines have needle bearings. I have one engine that I have had and ran for about 12 years. What is wrong with running Needle bearings?

Paul

w8ye what have you done in your conversion? Are you using a aftermarket igniction? what carb are you using? I was noticing that the shaft has a left hand thread, how did you find a prob hub for it? Any info would be a great help as I'm going forward with my motor project. It just looks too good not to.

My Mac's cylinders were modified by TKG. They have higher compression and C-H ignition as well as bored out carb insulators and 1/2" carburettors. They do not have synchro-spark, the timing is fixed a 28 degrees. They have aluminum Abel mufflers which are no longer available. Everything on them came from C-H ignition.

One was originally a 28 but I changed it to a 32 cylinder and piston. The other was always a 32.

The mufflers are still held on by the original spring retention set up.

Then I read you next reply further down about mods and bigger carbs

Mine is bog-stock (including muffler, carb, ports and ignition) and it IS gutless!

I think it's a 21cc? just cut down the shrouds took it apart and found out what it was. there is no thrust washer on the block I've got alot of engines to convert. thanks everybody for the help Erik