4-Stroke Frame-Mount Kit, Problems & Questions

highwayman

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Feb 12, 2008
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With the one piece engine mount that came with my 4-cycle frame mount kit, after mounting on the seat down tube first, there's about a one inch gap between the engine mount's front and the tube. The two brackets that came with it are identical and don't allow for any curvature of the frame, which is needed at the front but not necessarily at the back. I've seen a pic of the same engine mount on bicycle-engines.com but it has another piece to it and looks very adjustable. Their's looks like the same engine but mine is just the one piece mount. Should I drill a hole in my frame and mount one long, strong bolt thru the mount at the front and would it be sturdy enough using 2 or 4 bolts at the rear? I guess the 4-cycle mounts are somewhat different than the 2-cycle ones. My bike is a new Schwinn Point Beach cruiser. Pretty much the same frame style as a million other cruisers.
 
Half-moon sprocket clips should there be just 2?

My kit came with only 2 half-moon clips for attaching the sprocket to the spokes/wheel. 2 of these don't make a circle. Are only 2 supposed to be used with a big gap between them? And on the round rubber gaskets, one of them has 2 big chunks cut out of them about halfway through the rubber. Will this affect the trueness or flatness when tightening them down?
 
New 4-cycle kit - gas tank/petcock question

Ok, I saw a post about the petcock leaking gas. I'm just trying to install my first kit. I noticed the petcock is extremely hard to screw on to the tank's threads. Is this normal? I asked the dealer if I should use teflon tape to avoid leaks and he wouldn't answer me, but I saw elsewhere here that this should prevent leaks, so I'll be doing that.
 
4-cycle kits - don't they come with a manual?

Don't the Chinese include some type of assembly manual with the kits they send out? I got none at all. I can pretty much figure out most of it, but there are some things that even the most expert of mechanics won't know if no one tells them. In addition to a lot of different size lock washers and 3 sizes of bolts, there was a fiber washer that I have no idea where it goes. I thought maybe it was for the fuel petcock, but I don't think it would do anything unless the petcock was screwed all the way in to the tank. And my throttle/kill switch combo unit has 2 wires with naked ends. One wire is yellow, the other green. I have no idea how it's supposed to be hooked up. And there are other pieces that I have no clue what their purpose is. I thought the bike engine industry had been around long enough that there would be endless support and installation pictures posted (that you could actually see), but I was wrong. Every site I've seen is very lacking in this. If I was selling bike engines, I'd have as much as possible online simply to avoid so many questions. And I wouldn't send people to a myspace page to see pictures and make them register for that. Why not just put this stuff on their site? I don't get it.
 
My kit came with a 9hole sprocket, 2 rag rubber circular pads and 3 half-moons with 3 holes each. I think you got shorted. You need for each bolt to go through a moon to have something to tighten against.
 
hey highwayman...it looks like you're having some problems...i hope the 4-stroke kit guys are gonna be able to help you out, but right now i need your help. PLEASE stop stomping all over the forum, posting 4 new topics in a matter of minutes is not the way to win my heart. i've taken the time to merge all of them together...from now on use this ONE topic only to handle your build & questions.

and, for anyone missing the point: MBc is here and succeeding because of that lack of industry support. if we all pitch in here, we don't need those vague "instructions" we get from the maker. i agree with the point about registering, and that's why we don't require you join us to view our content.

in order for this topic to be of help to the next new builder, it would be great to have pics of your specific kit and parts, & it would be super-great to have pics of your final solutions...can you help us out with that?

take your time, & good luck...keep us posted in this thread about your progress :)
 
Engine Mount Issue

I take it that you cannot move the plate down far enough for the front tube to be close enough for the mount to work?

The mounting plate on the bicycle-engines is in fact 2 piece and adjustable. I have the same one and it works well on my Huffy cruiser frame. That is why I got that kit and not the other one. There seems to be two kits out there (for frame mounts, many others for racks) that use the same Honda engine or the lower priced Chinese version. The gearbox is different and the engine mounting plate is different.

If it were me, I would pony up for the adjustable plate. Unfortunately, it costs about $50, so I understand the desire to make what you have work. I would not drill the front tube and just run a long bolt. The engine weighs 12 lbs. and does vibrate even though it is relatively smooth. That will put a lot of shear force on the bolt and it is sure to fail after some vibration. You could try getting some plumbing pipe of suitable size and split it and try using that as a shim, both at the front and back to make it even....but without being there, I really cannot give any good advice.

Sprocket Mount

My kit came with 2 rubber "doughnuts" and two circular plates- one plate was two piece with four holes in one and 5 in the other. The second plate was 3 piece with 3 holes in each. Each individual plate must make an entire circle. I used both- from the ouside- sprocket, doughnout, spokes, doughnut, plate, plate (to lesen bending of the plates when tightened). I replaced the sprocket bolts with stainless ones of equal size. You must take care to tighten them evenly in a star pattern like you would lugnuts on a car. I numberd the 9 holed with a Sharpie (lacqer thinner takes it right off) to keep track and used a torque wrench, but feel will work fine. I then used a straight-edge laid across the sprocket and confirmed that the sprocket was parallel to the wheel by ensuring that the straight-edge was an equal distance from the rim. Done right, it may affect the dish a bit, but not the true of the wheel.

Fuel Petcock

I would use teflon tape or pipe sealer. However, I chose not to use the petcock. The Honda GXH50 that I have has a built in fuel cutoff and with the frame I have, the petcock interferred and made it impossible for the tank to sit straight. I used pipe thread sealer on all my threaded joints.

Manual Issue

Welcome to the wonderful world of a burgeoning industry dominated by manufacturers with little to no knowledge of the english language or customer service!

I assume you are doing this, but lay everything out first and see where everything goes before you put anything together. It is tempting to dive in, but patience is required. In the end, I used the supplied screws and bolts only to take to Ace to get the proper sized quality fasteners. Doesn't seem like we should have to do this, but the reality is that if you want a good result, that will probably be necessary. Based on the mounting plate you described, the link below is not your kit, but it should provide useful assembly information (look lower on the page)- this is essentially the "manual" that I got.

http://www.grubeeinc.com/USA/4 stroke.htm

They tell you this is a one day, one weekend project. Possible, but not probable if you want something done well.

GOOD LUCK
 
Last edited by a moderator:
4 stroke nightmare.........resolved

Aloha,

I bought one of the first (test engines) from Grubee..........$375+, one
of 10 he said were in the country.
Trial and error on my side I finally had to cut down one of my daughters'
aluminum scooters and made a nice motor mount which was a big remedy.My 4 stroker came with the thumb engager for the clutch that I had to con-stantly adjust. I finally went to a local welding shop and for an 18 pack of coors light (uggh) he spotwelded the sprocket/engager and it worked very well. UNTIL....
I was doing 40 downhill and the oil whisker broke and the crank bent.
I finally got the parts for it (after a year) and will soon be putting her back
on the road. If I had my choice and knowledge at the time I would have gone with the Honda GXH50 motor instead of the chinese knockoff.
Have fun, take your time and you will have a blast. Notice how many old
timers come up to you and say "I used to have one of these".

PS Don't forget the brakes, a front brake is a must. And wear your helmet
even on your test rides!


***5 cruisers 80cc--1 pull start 49cc--1 pull start 4 stroker--and 2 dax 70cc just wainting to be ridden....currently working on restoring 67 Schwinn Typhoon and 72 Schwinn Speedster 3 speed sturmer archer.***

aloha al
 
Last edited by a moderator:
hey highwayman...it looks like you're having some problems...i hope the 4-stroke kit guys are gonna be able to help you out, but right now i need your help. PLEASE stop stomping all over the forum, posting 4 new topics in a matter of minutes is not the way to win my heart. i've taken the time to merge all of them together...from now on use this ONE topic only to handle your build & questions.

and, for anyone missing the point: MBc is here and succeeding because of that lack of industry support. if we all pitch in here, we don't need those vague "instructions" we get from the maker. i agree with the point about registering, and that's why we don't require you join us to view our content.

in order for this topic to be of help to the next new builder, it would be great to have pics of your specific kit and parts, & it would be super-great to have pics of your final solutions...can you help us out with that?

take your time, & good luck...keep us posted in this thread about your progress :)
Well, augi, my kit is a frame mount and I made my posts in the frame mount forum. You said you merged them, but they are still separate posts just as I made them. I made an effort to separate the posts by specific problem, which actually has a bit of logic to it. If I had made one giant post asking those 4 questions at once, you would have jumped me for that, so one can't really win with your extreme intolerance of others. I didn't realize one could only make a certain posts in a certain amount of time. Should I maybe make only one post per 24 hours or something like that when I'm needing to get something done? You preach SEARCH SEARCH SEARCH but if you think about it, maybe people ARE searching and because, in your obsession for a neatly organized forum over a good nitty gritty answer base, you shuffle things around and mess up the search. Kudos to those who took the time to help. There are other forums where I can get straightforward, honest help. Augi isn't the only one out there and I think I've had about enough of his extreme rudeness. He has some serious issues.
 
Engine Mount Issue

I take it that you cannot move the plate down far enough for the front tube to be close enough for the mount to work?

The mounting plate on the bicycle-engines is in fact 2 piece and adjustable. I have the same one and it works well on my Huffy cruiser frame. That is why I got that kit and not the other one. There seems to be two kits out there (for frame mounts, many others for racks) that use the same Honda engine or the lower priced Chinese version. The gearbox is different and the engine mounting plate is different.

If it were me, I would pony up for the adjustable plate. Unfortunately, it costs about $50, so I understand the desire to make what you have work. I would not drill the front tube and just run a long bolt. The engine weighs 12 lbs. and does vibrate even though it is relatively smooth. That will put a lot of shear force on the bolt and it is sure to fail after some vibration. You could try getting some plumbing pipe of suitable size and split it and try using that as a shim, both at the front and back to make it even....but without being there, I really cannot give any good advice.

Sprocket Mount

My kit came with 2 rubber "doughnuts" and two circular plates- one plate was two piece with four holes in one and 5 in the other. The second plate was 3 piece with 3 holes in each. Each individual plate must make an entire circle. I used both- from the ouside- sprocket, doughnout, spokes, doughnut, plate, plate (to lesen bending of the plates when tightened). I replaced the sprocket bolts with stainless ones of equal size. You must take care to tighten them evenly in a star pattern like you would lugnuts on a car. I numberd the 9 holed with a Sharpie (lacqer thinner takes it right off) to keep track and used a torque wrench, but feel will work fine. I then used a straight-edge laid across the sprocket and confirmed that the sprocket was parallel to the wheel by ensuring that the straight-edge was an equal distance from the rim. Done right, it may affect the dish a bit, but not the true of the wheel.

Fuel Petcock

I would use teflon tape or pipe sealer. However, I chose not to use the petcock. The Honda GXH50 that I have has a built in fuel cutoff and with the frame I have, the petcock interferred and made it impossible for the tank to sit straight. I used pipe thread sealer on all my threaded joints.

Manual Issue

Welcome to the wonderful world of a burgeoning industry dominated by manufacturers with little to no knowledge of the english language or customer service!

I assume you are doing this, but lay everything out first and see where everything goes before you put anything together. It is tempting to dive in, but patience is required. In the end, I used the supplied screws and bolts only to take to Ace to get the proper sized quality fasteners. Doesn't seem like we should have to do this, but the reality is that if you want a good result, that will probably be necessary. Based on the mounting plate you described, the link below is not your kit, but it should provide useful assembly information (look lower on the page)- this is essentially the "manual" that I got.

http://www.grubeeinc.com/USA/4 stroke.htm

They tell you this is a one day, one weekend project. Possible, but not probable if you want something done well.

GOOD LUCK
Thanks for the info. Is the petcock extremely tight screwing it into the tank? Mine is so tight that I thought the threads were wrong, which is still possible. I have some teflon tape that I'll be using. I'm actually not jumping into this at all, I just got a kit with several missing parts and it really messes everything up. I laid out everything and made a count and saw right away that things were missing. Since there is no published pic anywhere of what's supposed to be in a sprocket kit, it's hard to know what's missing. Mine is definitely missing one of the half moons and the motor mount is 2 inches too short for even a Schwinn cruiser bike. The mount will, however, work fine on an old late 60s Murray bike I have but I really didn't want to use this old bike. The only thing that went right in this kit was the throttle/kill switch assembly, bu then, it will probably fall apart eventually.
I think the 2 stroke kits and the 4 stroke kits are basically the same except for the engine. The sprocket setup and tank all look the same. I'm just going to have to find the adjustable motor mount and spend even more $$$.
 
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