chain saw 2 the sequel

When pigs (with or without lipstick) fly lol....

I shot you some pics of the chainsaw mount. Let me see if I can't do a walk through for you.
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A couple of things that are noteworthy in this image ... The angle iron is used backward so that the engine sits on it. As I explained before I drilled holes in the bottom of the plastic case and used metal screws to hold the motor in place. If they ever get loose I will use loctite on the threads next time.

Also there are a couple of metal bars used as top braces so the engine does not fall over backwards. You need to support the top so it doesn't twist.

Also note the two L brackets bolted together to make a harp to tie the engine mount to the opposite side of the bike. Scissor hinges prevent the engine from twisting to much from it's own torque.

Note also that the engine mount is attached to the wishbone of the bike frame. It is on a hinge to allow movement up and down. The hinge is attached to the angle bracket.

The threaded clutch holder was just welded to a steel axle peg to make a drive wheel. I also have a plain pipe wheel that I can use if this axle peg does too much damage to the tire. The nut for that one came from a similar chain saw. I would take the threaded clutch nut to a good lawn mower parts store and hope they could match it with a nut. In case of the poulan I think it is a 11mm left hand thread. Same is probably true for the craftsman 42cc I think.

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This should give you a better idea of the harp, motor mount, and hinge relationship. The verticle bar is where the clutch cable hooks up to. Helps with the lift angle.

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This will give you an idea of the sandwich effect of how I hook my engine mounts to the frame. The frame is too small to drill and I don't weld. So I use a three point tie down. In this case I could get three points since i also went with a smaller wheel. One bolt (or two if you have room) in the center of the wishbone and then one on each side of it. (tighten them down evenly)

If you want pictures of the clutch with cable let me know I'll shoot you some.
 
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I could not stand it any longer damp and threatening or not I had to ride the bike. I first dry ran it and found that I couldn't pedal it. I spent all morning moving the motor mount to a different position then changing the crank set out for one from a 20" bike I had laying about. I had to adjust the clutch cable for the new engine position lots of things like that needed doing. The throttle isn't quite what it should be but.....

The 42cc engine even mostly worn out is a hoss. It climbs every hill on my short test track under power no whining at all. I had to constantly throttle back because it was too fast.

I would rather have the clutch on a brake lever but it works just fine on the bigger lever, Once i get used to it, I might find that I like it better. It is a little shaky now but man the power on the 42cc is way more noticeable than I would have expected. The full suspension bike after I finally got everything barely working is a nice ride.

I wasn't wearing a helmet because I took off on the spur of the moment just for a quick test run before the rain,. but I really should. The bike has power but I am a little unsure of it so it isn't very graceful...

If anyone were to ask me, I would tell them the full suspension would be ten times easier to build with a front wheel drive. 31cc WW on the front wheel would be the way to go.
 
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"The 42cc engine even mostly worn out is a hoss. It climbs every hill on my short test track under power no whining at all. I had to constantly throttle back because it was too fast."
That sold me on focusing on this concept for mass production for the American Beauty Bicycle motor company. (To long a name, eh?) What I am thinking is a clutch that pulls the motor away. Have it on vertical, spring loaded arms that swivel on the rear axle. Ease of installation and more of a one size kit fits all. 20" to 26" wheels.
I think I am going to owe you consulting fees Professor. Sorry, Mr Professor.

Yea, yea. But I am far away, heavily armed and have a faster bike. nananananaa

All kidding aside. You are great asset to the community
 
I need to fine tune this bike, then get used to riding it, then I'm going to sit on my asset for about a year lol. Oh I have to work on a trailer but that's It I swear.
 
If you are going to make a bridge over the tire to hook the motor to, you have an excellent start on an idea. You can slot the sides of the bridge to adjust it for the height of the wheel. Or just drill three different holes in the sides of your bridge one for each bike size. For the other I'm at a bit of a loss as to how it would work.
 
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I thought I did a cost breakdown on this bike, but since I can't find it in the thread here goes again.

The bike itself cost me $20 bucks used. I paid more because it was my grand daughter's bike.

The motor which has proved to be in better condition than I expected cost me $30.50 on ebay that includes shipping.

I stripped a lot of parts off a donor bike that I paid $8 for

One 20" tire $10.70.....

The mounting hardware probably cost me $25 or so....

Under a hundred bucks total for the 42cc chainsaw bike.


By the way I learned something today. You can interchange a coaster crank set with a cheap mountain bike's crank set. Probably not true with an expensive one but with the one I had it swapped right out. By switching to a 20" crank set I have a bike with a shorter pedal throw. Much easier on my knees.
 
Deacon- As you know i am contemplating buying a chain saw for an engine and i'll probably go with whatever is available at the local Home Depot or Lowes...So that means either homelite or poulan...How did you attach the friction drive to the chain saw drive shaft????? Is it threaded just like the Ryobi Weedeater???? (sigh...brings back thoughts of trying to find a left-handed nut for the standard drive shaft) Once i finally got that all sorted out it was extremely easy to attach different friction drives till I found one with the best diameter and grit. I wish i had welding skills...Chicks like guys that have skills.. And it would come in handy for motor bike building.
 
Now here is a kick in the butt... The poulan does indeed have a left hand threaded 11mm nut which you can almost NOT find anywhere. However they do have them available I bought one but it didn't do any good.

This is what you want to do. Pull the clutch and it will have a holder with wings. the reverse thread 11mm nut kind of thing. get your steel axle peg and then drill out the threads. Find someone here who will let you mail both pieces to them and have them weld the clutch nut thingie to the end of the axle peg. My neightbor did mine. Both the poulan and the craftsman have the same kind of clutch thing so I'm sure both were made in the same factory.

Now my problem of the day. The Brake cable stretches with every pull of the lever. The chain I bought to replace it snapped. I bought it because it was the easiest to work with but it obviously wasn't strong enough. The conduit I tried to use as a lever bent so it was too weak. The fence fabric stretch rod wasn't up to the job either but I had a brainstorm after I put the bike away for the night.

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I'm going to make a system of rods to pull the clutch. The fence rod should do for that. I am going to run a rod that is on a loose bolt so that it will move from a few inches above the engine, to the lever I made for the cable. I'm going to hook the rod to the bottom of the lever with another loose bolt so that it will pivot there as well. If that isn't strong enough I have no idea what I will try next.

Adjusting the throttle is another nightmare. That darn full suspension bike changes configuration when I lift the engine, Then again when I sit down on it, then again when I release the clutch lever. Once I get the clutch fixed for sure I can fine the best average setting for the throttle cable. With the clutch changing constantly it has been a wasted day. I did redo the mount yet again.

Same design just have to switch out some components.

Don't weld hinges with plastic bushings lol They get really shaky when that plastic bushing melts.
 
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Thought I would show you the latest in friction clutch design at least my latest.

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In image one the chain and spring is the the poor mans turnbuckle and spring. It is adjustable in half inch increments. Worked pretty well for adjusting the tension while I was out testing it.

the second image is the rod connection it has to be loose and double nutted to move as it pulls forward.

The third is the lever itself.

I am just now getting to test this engine. I notice a couple of things so far. The motor I can run at very slow speeds and still pick up for the next hill. It just feels beefier.
 
I spent the afternoon riding and adjusting the throttle and choke rod. I changed out the conduit for the fence fabric stretcher bar. It works fine as the rod and is just as cheap as the conduit. The advantage is that it is easier to fit along the bike. I really do like the way this clutch works. I might just convert my other chainsaw bike to this clutch system.

I rode the bike on about five short runs probably two to three miles each. Tomorrow if the rain holds off, I am going to ride it off and on all day. I would like to feel more comfortable with the clutch mechanics. I would also like to make sure the throttle works.

About the throttle. I used a shifter and didn't use a helper spring. The shifter forces the cable back through the sheath. It creates slack at the engine so the carb spring is strong enough to return it.
 
that is what is on the chainsaw2 bike. It works great, thanks again. By the way what is the diameter of the peg do you know.

Now here is something for you to think about. The clutch on a full suspension bike also adjusts the tension. I guess it does on all bikes but with the lever I have made, it is possible to control the tension from the front.

I have the lock bolt and nut tight so I can lock in an infinite amount of tension on on the wheel as the bike rolls along. On flat ground I can set the tension light to save the tire and probably less strain on the engine, then on hills I can increase the tension to get more bite.

For some reason the bike will accelerate up the hills now. Some are a match for it, but not many. Most of them it just eats up. The adjustable tension is a integral part of it I think.
 
That peg is 1.5 inches, just like the one that I just put the JB Weld on. I think that some tires have more slip. No matter what I did it slipped all over my tires. I'm running what looks like a standard balloon type cruiser tire, it's a street slick. I don't know specifics of it as it came with the bike.

I use the clutch handle to lift the engine a bit and change the tension. I have a velcro strap that I use to hold it up. It works pretty well. I'm thinking that a grip shift would be the best thing for it and I'm attempting to find a cheap donor bike off c list to harvest parts. If I had a grip shift I'd be able to lock the engine up or down...
 
I use the shifter as a throttle. I need the lever action for lifting my engines. I think of course I never had tried a shifter as a clutch control.

I rode 3 of my four bikes today and found that the 31cc ww still has the bog down problem with no predictable pattern. I am going to try a new fuel filter and some new gas lines before I start to adjust an almost new carb.

But the real point was going to make was that all three of the engines are acceptable for use.

The 31 Ryobi (when it doesn't bog down) pulls almost the whole test course. The amount of help required is minimal.

the 33cc chainsaw pulls the course with no help but it does slow down on a long or sharp incline.

The 42cc chainsaw pulls all the course and does it with a lot of throttle left over. It is by far the stronger bike engine.
 
this is pretty much how the chain saw 42 is going to look forever. I did put a larger seat on it but the camera broke before I shot that pic.
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deacon said:
I rode 3 of my four bikes today and found that the 31cc ww still has the bog down problem with no predictable pattern. I am going to try a new fuel filter and some new gas lines before I start to adjust an almost new carb.

The 31 Ryobi (when it doesn't bog down) pulls almost the whole test course. The amount of help required is minimal.
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I just got back from one of my early evening rides and let me tell you it was the first time that the engine never once bogged down on me and ran like clock work the WHOLE time. IT was a fantastic fast ride. 25 minutes, 5 miles and that engine ran perfect the whole time. It was fantastic. I'm hoping to get a lot of these rides in before it gets too cold and we get that white s&!t some people around here like. I think they have people who shovel their sidewalks and driveways for them.

My ryobi bogged down a lot, but I had the fuel mix wrong, this time around I was very careful about how I mixed it and got it darn close to right. I also pulled my plug cleaned it off with some 800 grit sandpaper, and scrapped the outer edge of it so there was no more black deposit, looked almost new. I also moved the magneto down and away from the flywheel to the farthest extreme that the adjustment would let me. I did all those things at once and it doesn't bog anymore.

Taht 1.5 inch spindle is just about perfect for getting around here, I don't have to go WOT all the time and when I do I get a nice burst of speed and plenty pf power and if I pedal... Watch out.

I really like that lever that you made on the chainsaw bike. I wonder if a lawn mower throttle would work, you know the ones with a rabbit on one end and a turtle on the other that lock in place? Just an idea that comes to mind after looking at your pics.
 
Actually I had that thought after I made mine, but then I realized how heavy that engine is. The size of the lever makes easier to tilt the engine.

Glad to hear about the ryobi. Mine runs like crap at the moment. I'm going to pull the gas filter and run it without few times to see if that is it. If not I will have to try the magneto thing. The carb isn't bad I know. If there were some rhyme or reason I would feel better it just does it for no reason at all. No common thread.
 
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