2.5 hp HF friction drive.

I must have been living right this weekend is all I can figure. I pulled that muffler and it had three bolts in a perfect triangle pattern. I was therefore able to rotate it s120 degrees and move the exhaust away from me. The one problem is that the muffler touches the muffler pan/guard and that touches the seam of the gas tank. I'm hoping it won't blow me up too soon or too far. I rode it a mile and it wasn't even warm or the gas tank so maybe i can get a few miles before it blows me into Tuesday.

But that is one nice engine for a bike. Now that the kinks are gone, it is one stout little engine.
 
time to wrap this puppy up...

so first some pics
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A little about the bike. Thrift store 24" mt bike with rear wheel removed. 20" wheel from a donar thrift store bmx bike. Handle bars from a coaster bike I had laying around.

Engine is the greyhound 2.5 hp HF engine cost $98 tax and shipping.
sprocket for 41 chain used to support 1"Id pipe nipple.

After I made this picture I spent the morning switching the gas tank. The one in the picture developed a tiny leak. I wanted to remove it because it sat to close to the muffler anyway so I switched it out. When I start the engine or stop at a stop sign I lift the motor off the wheel. If the engine dies once it is warm, it will drag start by lowering the motor to the wheel.

I have heard talk about raising the rpms on this motor can anyone explain the easy way if there is on to do it. I am not using that throttle I have the handle bar throttle wired directly to the carb lever. Do I need to remove the other stuff behind it. All that junk under the gas tank.
 
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deacon said:
time to wrap this puppy up...

so first some pics
ImageShack® - Online Photo and Video Hosting
ImageShack® - Online Photo and Video Hosting
ImageShack® - Online Photo and Video Hosting

A little about the bike. Thrift store 24" mt bike with rear wheel removed. 20" wheel from a donar thrift store bmx bike. Handle bars from a coaster bike I had laying around.

Engine is the greyhound 2.5 hp HF engine cost $98 tax and shipping.
sprocket for 41 chain used to support 1"Id pipe nipple.

After I made this picture I spent the morning switching the gas tank. The one in the picture developed a tiny leak. I wanted to remove it because it sat to close to the muffler anyway so I switched it out. When I start the engine or stop at a stop sign I lift the motor off the wheel. If the engine dies once it is warm, it will drag start by lowering the motor to the wheel.

I have heard talk about raising the rpms on this motor can anyone explain the easy way if there is on to do it. I am not using that throttle I have the handle bar throttle wired directly to the carb lever. Do I need to remove the other stuff behind it. All that junk under the gas tank.
Click to expand...

Looks like you have a keeper Deacon. Just remove the linkage between the governor and the carburetor and it will rev to at least 5000 rpm. You do not have to do anything with the rest of the governor stuff. you will have to rig a throttle return spring though. Look at the last post on this page and you can see how I did mine. http://motorbicycling.com/f36/finishing-greyhound-build-12738-4.html
 
I already have that stuff in place. I just wondered if I had to do anything to the old crap there. The motor has great torque and the speed seems to be improving a little each time I ride it.

I put a trailer on it this afternoon and it improves the bike a bunch. To attach a trailer i use an L bracket near the rear axle. Then I use the trailer arm on one corner of the trailer and have it stand out from the bike at the attachment so that it pulls straight. One of the benefits of doing that is I get to add a second kick stand at the rear axle. All that stuff, the L bracket trailer hitch and the kick stand are under the motor tumor on the side so they are out of the way. I really am enjoying this bike so far.
 
I made a post in my, why I love friction drive thread, with general information about this motor's suitability for friction drive. If you are considering it you might want to read that. Basically the motor requires some very minor changes like leveling the gas tank and rotating the muffler to be perfect. Thanks for having read the thread.
 
This one should last you for a long time. I have almost 2000 miles on my HF 2.5 and it is running strong. After the low oil sensor and the in line filter I haven't had any trouble with the engine.
 
I switched the tank so I went with an inline filter and I left the fuel cutoff in line as well. It has the feeling that it needs the bolts tightened once in a while then just ride it. That's at the point where I am. I do believe I might have to rerig it as a fake tricycle though. You know bike with big training wheels. I built a couple of them before to increase the stability for my bad balance, but even that is a no big deal project. Just take my trailer and put a second tongue on it.

I woke up with my balance gone today so I have walking around with a cane. My wife threatened to call my family If I went near a bike. I am trying to avoid being screamed at this week. However I took a nap in the afternoon and am much better now. I might slip in a little ride. i am still evaluating the stability of the bike.
 
I have ridden this bike off and on about twenty miles now. I have already given the low down on the build and the changes I had to make to the engine (very minor) so how is it doing as a friction drive.

It's been about twenty miles probably five hours and it's still breaking in. First of all they say not to load it up the first twenty hours so I have the tension set low. It is very low indeed, but it pulls the hills beautifully. It will actually go up big hills accelerating. I let off the throttle most of the time to no more than half throttle to help with the break in.

The down throttle has some to do with the engine is too big for the local laws, and I wear a bike helmet not a motorcycle helmet. Yes I have two motor cycle helmets, but I prefer the bike helmet. At fifteen miles an hour I'm not too worried about it not being enough protection. Real bikers (as my wife calls the pedal jockeys) can do as much down hill as I pull. If they are safe with a coffee cup helmet, I should be just fine.

This engine at the price it is right now is the ideal bike to build a friction drive with.
 
The thing I love about Motor bikes is that they are never really finished. Last night I found that the exhaust I moved to keep from burning my leg melted parts of my gas tank. I figured that needed attention right away. So I resurrected the original gas tank, found my JB weld and made some patches at the poor welding of the attachment points. I let it dry over night then made some extentions to level the tank since it is a center feed, then tested it and it seems to be okay.

I love working on the bike and I even love Itching about the Chinese welding when I know mine would be ten times worse.
 
I did not intend to build a plug and play bolt on system when I started this bike, but it was worked out that way. I am going to make the last part of it plug and play today.

There are three elements to the build. One of course is the motor. When the motor mount finally worked itself out, it was held onto the frame with one 1/2" bolt and one 1/4" through the wishbone behind the seat. A spring holds the rear, along with a piano type hinge to keep the motor more or less in line and as a stop to keep it from going too high.

Then there is the throttle which is just a brake handle and cable attached to the mount of the motor using the cable holder/stop from a brake harp. I have lots of bike parts from having junked out so many bikes. So I could in effect remove the brake handle, used as a throttle, roll the whole thing up and put it in a box and ship it attached to the motor to make an easy kit.

The third and probably the most important thing is the lift system. Right now mine is attached through a hole drilled into the bike frame. Today, if I don't go stupid again, I am going to make the whole lift system plug and play. It already uses a plastic coated cable to lift the motor. Last night I put a turnbuckle in the line to adjust the cable so it wouldn't require taking the cable apart to change the lift amount of the system. Today I am going to find something I can use to make the whole lever system free of the bike. After I get it made, I am going to attach it to the bike frame with a couple of simple hose clamps. Therefore making it completely plug and play. I will be able to swap it between bikes and recommend the whole thing for a simple bike build that will rival the china kit for it's simplicity. I do not want to make bike kits. I just want something a guy can take and say, hello I can do that. with limited skills and tools.
 
I did a quick mileage test on the bike this morning. It wasn't mythbuster approved, but it appears that the bike gets well over 75mpg as a direct friction drive. It may be considerable more but that is a minimum figure I think one would be safe to use. That was in a pretty hill filled area. So I would think that would be a very safe estimate. Also since I didn't use an odometer but relied on Yahoo maps the figures may be a lot more depending on how they figure routes. I doubt that it would be any less.
 
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Running this motor without the clutch and using the lift bar creates some problems witht he fuel feed. The constant supply of fuel to the carb is not easy to maintain when the motor is tilted and is will be when used this way. I never could get the tank from the factory to stop leaking because the support welds were bad and the vibrations kept breaking the JB weld seak. I might try it again with the factory tank by removing the supports and resealing the whole bottom of the tank. Most likely I will continue to go with the weed whacker tank I reconfigured and just carry extra gas since I don't really go long distances.
 
You must be really lifting the motor to get that much of a change. My Lifan raises less than a 1/2" to disengage. I bought a HF engine. I am sure it is a good engine from what I have read here on the forum, but the quality of the external parts is way inferior to the Lifan. The Lifan looks more along the quality of a Honda. None the less am looking foward to another build using the HF engine, friction drive of course!
 
it isnt the lift the motor is mounted at an angle. Then when it goes up hill the angel increases and the gas sloshes back and forth. I think I have my intake too high in the tank as well. The tank needs to be mounted differently because when i run it with a full tank of gas it's fine. below have a tank it sputters when it isn't level.

It also backfires when I let off the throttle when it's hot. I don't know what that's about. I probably need to adjust the carb. At the moment I'm still trying to get the running gear setup. I have a new 24" wheel coming when I get it on tomorrow, I am going to level that engine out and see what I can do about all the other issues then.

But I love the power of that engine regardless. It is just a sweet sweet ride. Not fast but plenty strong. It's what I needed all along. Speed is wasted on me.
 
Im running a one inch pipe nipple smooth now, but I was interested in your 2" roller how is that working. One more question. Have you ever tried to contract cement a tire sidewall to the steel smooth roller. I think I tried it with a knobby tread and the peeled off, but I think im going to try again. The weld slag I put on my bumble bee wore of the tire in a hurry.

What are you using for a roller. how are you making yours by the way. I need lessons lol.
 
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Backfiring when decellerating is usualy always caused from small exhaust leaks close to the cyl. head. Check bolts, gasket ect.
 
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