McColough 32cc chainsaw bike

I have a box I strip parts from old motor i used on bikes. My guess is maybe ryobi trimmer. It looks about right for that.
 
The carb is not the original one Im looking to build a weed whacker carb first that is the zammy.. The parts guy here insists that he needs the numbers so lets see if he can match it up or if it winds up being the H class carb
 
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It just dawned on me that you guy probably think I'm loony for building a weedeater carb, rather than the original carb from the chainsaw. You are probably right. I am doing it because I think it's interesting that they work on a motor of totally different size.

I do think the chainsaw winds out just a little less, which I fine with me. I am not about speed. But I think the information might be of use to someone else some day. By the way the only thing is the crankcase vent holes have to line up. The gasket from the weedeater seemed to have a bigger hole for that vent so it probably works a little better.
 
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I have decided since I only have to choke the thing once, I am going to use the carb i have for now. I am still going to rebuild the other one and put it on eventually though. This bike may not last a week seems a shame to not test it before I spend any more money on it.
 
Yes the paint scheme says cheap *******.

Oh I have a very nice seat and I put it on. Got everything done but im too tired to ride it tonight. Not often I am so stumbly that I can put off riding a new bike.

My grandson is about two years old and is just beginning to talk better. He gets tiny little cuts and calls them boo boos. He is fascinated with the number and size of grandpas boo boos
 
rustycase said:
Tnx for the advice on the carb... I'm gonna do it in a position where I can make adjustments to it easily. I'd like to point the cylinder head down, because that would put the crank with FD up highest, and easiest to get at the tire. I think... but I'm still concerned about residual fuel draining down to foul the plug when it's shut off. probably better to have that excess charge setting in the crankcase, then it will mix in once the motor is started again???
rc
Click to expand...

Just a quick heads up on that downward cylinder thing... you have to be careful that excess fuel doesn't leak threw the carb down the intake track and pool in the cylinder, it WILL hydraulic the head and cylinder possibly cracking the cases at the head stud or cracking the head or barrel...It might even explode.
Just because the diaphragm carb will work and the engine will RUN in all positions doesn't mean the engine at rest will like it.
Just my 2 cents worth.
FR
 
To be honest it never occurred to me that the engine did anything when it was shut down. I guess I don't know enough to know what I don't know.

I finally got the mount finished I think. So after I ride through the park on my ebike, I'm going to give this chainsaw bike a shake down. Then I am going to get a kit and rebuild that carb (somewhat) to have it ready in case I get really tired of choking this bike by hand.

Unfortunately I have to cut the grass which will interfere with my important stuff like testing the bike.
 
I finished the bike last night. Today I rode it. First I went about a hundred yards and realized I didn't have enough tension on the spring so back to the house for a change of springs. Then I took off again and man that thing did just what I expected and just a tab better.

I use the same mile as a test for all my bikes. it had one short steep hill and one long slow climb. All my bikes except the greyhound have bogged a little on the short steep hill. This one was no different, but it did pull the hill on it's own. Then I turned the bike around and headed back. When I hit the long slow hill, it pulled it just fine. The 31cc ryobi needed help so this bike has a little more torque than that engine.

The engine performed just fine with the carb from th 25cc blower. I even like the click sets and the way it is wired the return spring when I shut the throttle all the way off kills the engine. A nice safety feature. I don't need the kill switch at all. The first click is idle.

At thirty two cc this bike does really well. No I'm not going to set any land speed records but it runs nice and I can use it to run to the hardware store. Or out for coffee. I do need to look for something to build a larger gas tank. Those weed whacker tanks are a little small.
 
okay chainsaw people I have a question, when the bike is cold I go through the three step start and it works fine. If the bike shuts down at an intersection I just give it gas and drop the engins and it takes off. But if the bike sits fifteen minutes, I don't seem to be able to start it.

I can't choke it easily so is choke the problem. I don't remember having to choke a hot engine, but maybe I did and just dont remember because it wasn't hard to do.' I am waiting on a kit to build a carb with a working choke lever.
 
Deacon, what put Mac out of buisness were bad ignition modules. They designed most of their smaller engines to use the same unit. They begin to fail in droves, and Mac threw in the towel after all those years. They got caught in a bad NAFTA deal. All that said, It is possible the unit on your engine is heat sinking, and the spark is on vacation. Pull the plug after it sits hot and check for fire. If so its probably just a matter of time. Check and see if the module is white, as I remember thats the bad one.
 
ah OKay. Will check that plub after my next ride, if I get started again.

Where is the module on this thing. Give me an idea where to start looking for it.
 
thanks the bike is just an easy way to get a bike that works pretty well. It isn't near the quality of these other guys but then I'm not that mechanical.

I did manage to get it started. After cannonballs advice I decided before I checked the module I should be really sure the bike wasn't just harder to start then I thought. So after a fifteen minute cooling off period, I took it to the test track got up some speed and dropped the motor. It took a few pedals but it fired and ran fine. I guess it is going to be hard to start hot, but maybe it will work okay.

32cc is dead slow but it's fine with me it will climb most of these hills around here without any help. The one thing it also has is lots and lots of vibration. I am going to have to try to cut down on that since that kills motor quickly.

Cannonball this case doesnt have a top lol. The two sides bolt together and they are all there is. I will check behind the recoil one day if I have to pull it for anything else. That module is more than I paid for the bike. I won't be replacing it with a new one, that is for sure.
 
I rode the chainsaw bike out to the lake this morning. The 32cc is a little small for the big hills on that run. My wife was behind me in the car and said that the bike dropped down to ten miles an hour as it climbed the big hills. That a little faster than I thought. I would have put it under ten and over five. It probably cruises at a little over 15mph with that almost 1" outside diameter smooth spindle.

It needed to be adjusted so I did that when I got home. I'll be testing it more but I would say that the 50cc is about minimum to climb the hills around here, but 32cc would be fine for flat ground like at the beach or even most of the inland but still coastal areas. I need the exercise so for now this bike it fine. I figure by the time I find a better engine. It will be worn out.

Actually it depends on the carb kit I have coming in. If it does alright, I might give non working weed eaters like the 31cc bolen and ryobi another look. Vibration killed most of my engines. Bad carbs put a lot of them on the market. If I run one for a while and the vibration heat kills it but I can find another one free and can just do a part swap, it might be a viable building technique.

The difference in using the small WW motors this time is, I would be expecting them to fail. I would be prepared to just bolt another one on and switch out the carbs plugs ect. Kind of like the room full of bike parts I have now.
 
You have probably reduced the power somewhat with the blower carb. If you get the stock carb up and going it should make more power. A 33cc saw makes way more power tha a 31cc WW. See the carb through.
 
I know it winds out less but I kind of like that about it. It sounded like it was going to blowup when it wound out with the stock carb. It still loses its grip when I wind it out too far. The bike has some more fine tuning before it is where I want it but it is good for what it is.

I took the bike out and tested it after I made the adjustments to the mount and it works some better, I need to ride it a few more times to be sure, but I think it is good to go. Just doesn't climb big hills real well about the only think I had that would had the 3.5 Tecumseh and the greyhound. they were just more motor than I wanted on a bike. Somewhere there is a happy median for me. This bike might actually be it. I don't mind pedaling going uphill as long as the pedaling is no more than a small amount.
 
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