My mini thumper

paul

Well-Known Member
Dec 23, 2007
5,548
39
48
63
Kalamazoo, MI
very nice cruiser. i like it alot. what kind of set up? sprocket size and what kind of speed you getting out of it? i am thinking of building a 4 stroke motorized bicylce next
 

Egor

New Member
Jan 30, 2008
714
0
0
Hurricane Utah
Cruiser - I like it. What do you think of the engine? I was going to get a 4 stroke next, and I was curious about the two that are out there. That one doesn't have a neutral or an over ride sprocket. Is it hard to pedal, engine off? Have fun Dave
PS: I had a dream last night about a twin engine two smoke, I have to build it now that I have seen it.
 

Can Harm Hen

New Member
Mar 1, 2008
38
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0
Davis, California
Heh, you've got the same frame that I have, except in red and with 2 more strokes than mine. :)

BTW, it looks like you've got enough clearance to do away with the chain tensioner. I'd shorten the chain and chuck the tensioner.
 

Easy Rider

Santa Cruz Scooter Works
Jan 15, 2008
2,144
4
38
Nor*Cal
Nice Bike 66! Is it my imagination or is the tank bigger than the 2 cycle gas tanks?
BTW how do you like that air horn?
 

cruiser66

New Member
Mar 4, 2008
51
1
0
Westport, MA
Thanks for the interest. Here's a quick rundown of my ride. This has the Honda chinese clone engine and the trans does not have the disengage feature or the freewheel feature like the more expensive GruBee kit. I installed a center two leg kickstand for stability and so I can tune and check the running gear. A freewheel sprocket on the tranny would have been nice, but I like to use the engine for braking and the added drag of the tranny when pedaling isn't too bad since I do have seven speeds on the pedal side. The engine starts easily and quickly and is smooth and quiet. The original rear sprocket was a 48 tooth, but I changed to a 44 to reduce engine speed at cruise and increase top speed. I have gone about 28 mph tops so far, but since I really don't know what the top rated rpm is, I tend to be conservative. I do have a tach and I limit it to 7500 rpm. I'm considering a 36 tooth sprocket which should put me in the mid 30's for speed.

Originally ran tranny with grease and a dry clutch. It was OK but clutch action was a little grabby and there was some gear whine. I didn't use oil because these trannys like to spray oil out the vent hole. After I fixed the spraying problem, I put in 5 ounces of 75W90 synthetic which really improved clutch action and reduced gear noise. I don't have much running time on this setup, but I think it should run well.

I recommend the air horn - very loud - about 30 blasts per charge. I do use a bell for pedestrians. The loudness of the horn can be adjusted, but I prefer full blast for when you really need it. Also, the fuel tank is the same as the two stroke model - standard size.

I think I answered most of the above questions. Anymore? Let me know. This is my first motorized so I know I'll be able to learn a lot from you guys and I'm happy to be able to contribute.

Ray
 

paul

Well-Known Member
Dec 23, 2007
5,548
39
48
63
Kalamazoo, MI
ray i imagine you step back and look at your motorized bicycle and smile big time. its clean and very sharp looking. i ussually don't like the red cover on the four stroke bicycle engines but on your ride it looks good like it belongs
 

cruiser66

New Member
Mar 4, 2008
51
1
0
Westport, MA
Thanks again, Cruiser. I guess the red engine does go OK with the rest of the bike. I was thinking about all black, but black and red is a nice combo. This whole project went together smoothly. I took my time over a 3 day period working on and off. Now I can customize and fine tune and modify without worrying about voiding warranties - just have fun. I wonder if anyone else with this motor kit has tried a 36 tooth sprocket...... I wonder how many other members even are running this kit.
 

Norman

LORD VADER Moderator
Staff member
Jan 16, 2008
2,605
2
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pampa texas
Your bike screams for a straight pipe It would sound good on a 4 stroke might even go to a larger dia. could sound like a mini hog. I want to some day get one of these 4 strokes and play with the timing and look into making a different cam. I start slobering of thinking what could be possible with a engine like this. Nice bike.
Norman
 

[email protected]

New Member
Sep 25, 2009
117
0
0
San Diego
I am currently running a 2 stroke, but am about to do a 4 stroke. Any suggestions. FYI i know nothing about motors, but am very curious as to what you were talking about with the clutch options, and gear boxes out there. I thought they were all the same, except for those new honda and the whatchamacallit it clone with the sick 5:1 belt thingy (which i am assuming is the same motor, just different gear box?). I just have a better use for 500 bucks. I'm wanting to keep it cheap. What options do I have, and which what should i avoid? Thanks guys
 

rbrtlndhl

New Member
Jan 27, 2010
53
0
0
La Crosse, WI
I am currently running a 2 stroke, but am about to do a 4 stroke. Any suggestions. FYI i know nothing about motors, but am very curious as to what you were talking about with the clutch options, and gear boxes out there. I thought they were all the same, except for those new honda and the whatchamacallit it clone with the sick 5:1 belt thingy (which i am assuming is the same motor, just different gear box?). I just have a better use for 500 bucks. I'm wanting to keep it cheap. What options do I have, and which what should i avoid? Thanks guys
Your best option, IMO, is to contact Terry Blow... He is a member of this forum, and appreciates that you are, as well. I just ordered the belt tranny setup you are referring to (The Grubee 4G T-Belt Drive with the Chinese Honda clone) as a complete kit, for 320 bucks after the 20 dollar Paypal fee. This sale is only available as far as I know until April 1st, so you'd better jump on it while it lasts.

This, as far as I know, is the quietest, and seemingly best mechanically, transmission made for these four-strokes. For other transmission options, see the gearboxes sticky thread in the 4-Stroke Engine Kits section of this forum.
 

Cowboy Rider

New Member
Apr 20, 2009
75
0
0
Illinois
I noticed the air horn's tank too, I have one like that. Sure can come in handy with some of the idiot cars drivers we have around here. They see a bike and have no clue that we're going nearly 30 MPH on it!

Just the other day I was running around on the bike I have with Out the horn. (Gotta get a second one!) Anyhow, I did my arm signal to show my intent of a left turn to the car at the stop sign. Sure enough, she pulls out right in front of me!! I locked up the rear brake and skidded right nicely to avoid a collision, but that air horn would have been appreciated at the time.