The Backwards Engine Experiment, 1939 Colson

GoldenMotor.com

Allen_Wrench

Resident Mad Scientist
Feb 6, 2010
2,784
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Indianapolis
The "Hot-Foot Express" is an awesome bike. Who knew putting your head on backwards could have such advantages (though technically it's the whole top end I suppose). You know, if you're handy at fabricating with sheet metal, you could make a little air-cleaner cover with a built-in ram air scoop pointing forward on it.
 

Dan

Staff
May 25, 2008
12,765
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Moosylvania
The "Hot-Foot Express" is an awesome bike. Who knew putting your head on backwards could have such advantages (though technically it's the whole top end I suppose). You know, if you're handy at fabricating with sheet metal, you could make a little air-cleaner cover with a built-in ram air scoop pointing forward on it.

lol @ the hot foot express. Would keep you on your toes
 

hellhammered

New Member
Jan 23, 2010
138
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0
Maine
thanks.

i dunno, 30, maybe 40...tons?

it's pretty heavy duty, but it doesn't weigh that much. probably weighs 50 lbs now. still goes 40-45mph no problem though...
The reason I ask is because I want to motorize my Flightliner, which is a tank. That's good news, it probably weighs about the same as yours. Cool, Thanks!

 

bairdco

a guy who makes cool bikes
Aug 18, 2009
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living the dream in southern california
i'm all into the heavy duty american made bikes. it's not so much the weight, it's that they're solid. my bike doesn't rattle, doesn't flex, no creaks, nothing's broken but the 70 year old skiptooth chain, and it'll outlast the factory that china bikes are made in...

i think a nice heavy bike is better for these engines anyways. for exactly the reason's i've stated above.
 

Dan

Staff
May 25, 2008
12,765
115
48
59
Moosylvania
The reason I ask is because I want to motorize my Flightliner, which is a tank. That's good news, it probably weighs about the same as yours. Cool, Thanks!

OH Man, that is gonna make for one sweet MB! Post lots of pics HH
 
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bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
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63
living the dream in southern california
put a supertrapp disc only muffler on it. ran it with 6 discs and it was a little rough and it didn't have the bottom end power it used to, so went down to 5 and it smoothed it right out. went down to 4 and it quieted it back down to about stock, but with a better sound, and performance seems good, but only rode it about a half mile today. (posted another thread about that already.)

i've tried out a few different air filter mods, and i made a velocity stack type, wide open filter.

didn't work. i had to run it at half choke. i made it out of aluminum, and it didn't seem to channel the air in correctly. i basically made an opening the size of the throat of the carb, like the size of a quarter. it was probably a poor design on my part, so i junked it.

the "ram air" effect myth seems to be busted.

made another out of some piece i found at a swap meet, mighta been off a dellorto. works great again. i'll post some pics of it tomorrow.

motor's still running strong with no problems at all, except it's getting too fast for the bike to handle, so i'm about done modding it out.

also figured out my hard starting probs finally. i just need to press the tickler till gas drips out, and she fires right up.

i got some more ideas, but i'm gonna save them for my speed bike build, coming soon...
 

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Humsuckler

New Member
Jul 28, 2009
457
1
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Ontario
im pretty sre youd be the first one to put a supertrapp on a chinagirl haha

looking good! im thinking im gonna try this for my project errand-doer MTB/Cruiser
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
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living the dream in southern california
well, after months of basically trouble free riding, i finally got some troubles, but they're not due to the backwards engine...

my chain busted again. i think it's because the motor puts out more torque than normal bikes, and the chains i'm using are crap. i was gonna buy a #41 diamond chain this weekend, but my bike didn't last that long.

so, when the chain snapped, it took my rear motor mount with it. sheared off both bolts, one of them inside the motor. one came out no prob, the other was pretty well stuck.

so i get out my drill, etc, and found out it cracked the case, and oily grease is coming out from under the clutch.

inspected it some more and found the casting that holds the pin for the clutch actuator is blown up, too.

so, anyone got a Grubee Starfire GT4 case laying around?

i ended up installing a brand new motor, still backwards, that i was gonna use for my new bike build. and it works great, so far (at least for the 1 mile i rode it today.) just gotta buy some good chains.

(sorry, no pics. can't find my uploader thing after i moved...)
 

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
I have KMC 410 H 1/2 x 1/8 on a 5.8 hp Morini that has been indestructible. I weigh in 240 pounds not including the bike. Been loving it..
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
264
63
living the dream in southern california
i was using a #41 from Fastenal, but it was made in china. it fit better than the stock 415, and looked heavy-duty, but it broke about a month and a half ago so i had a 415 kit chain on again.

the sprocket alignment is dead on, and there's no excessive wear on the sprockets, so all i can think of is the chains are just garbage and can't handle the load i'm putting on them.
 

Allen_Wrench

Resident Mad Scientist
Feb 6, 2010
2,784
26
36
Indianapolis
i was using a #41 from Fastenal, but it was made in china. it fit better than the stock 415, and looked heavy-duty, but it broke about a month and a half ago so i had a 415 kit chain on again.

the sprocket alignment is dead on, and there's no excessive wear on the sprockets, so all i can think of is the chains are just garbage and can't handle the load i'm putting on them.
I'm supposing the Hot-Foot Express has some serious oomph to it. You gotta fix that thing. I kinda like that bassackwards bike. It's cool.
 

broHSI

New Member
Jul 27, 2009
89
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0
USA, CA
so, when the chain snapped, it took my rear motor mount with it. sheared off both bolts, one of them inside the motor. one came out no prob, the other was pretty well stuck.

so i get out my drill, etc, and found out it cracked the case, and oily grease is coming out from under the clutch.

inspected it some more and found the casting that holds the pin for the clutch actuator is blown up, too.

so, anyone got a Grubee Starfire GT4 case laying around?
Hey Baird
i gots two of them, one you know about that I have a top end kit for

The other starfire motor has a destroyed left crank bearing and trashed seal behind the magneto.
Customer ran it with very little oil so he said. Also scratched up the chrome in the barrel and the piston when he took it apart.

Gimme a call
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
264
63
living the dream in southern california
brohsi, cool, i was gonna call you about that.

and Allen Wrench, it's already back up and running. put in a new motor that i was gonna use on another bike that i've been hotrodding. rode it today and it's just as fast as the old one.

seems to me, if you blueprint the motor right, there's basically no break-in period.