301cc Predator 8hp - Put one on my doodle bug & engine info inside

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BusaBug

New Member
#1
#1
So a lot of people know now of the harbor freight 8hp 301cc engine they put out - but there isn't much info out there on them. I Now have one on my doodle/baja bug - and hopefully I can help answer some questions. It uses the same gaskets/head as the honda 270 - and pretty much everything that the 270/390 has will work with it.

My mods: adjustable 390 carb - stock one isn't adjustable
exhaust
Milled the head .052 and got the thinner head gasket
Lighter flywheel
running a 420 chain
Torque Converter
hydraulic Brake
Nitrous Kit

Put a rear tire on it tonight - damn thing is a wheelie machine!

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R

Ratchet

Member
#2
#2
Great info. I must have started my thread when you posted yours. This is one of my engine considerations for my project I will be starting.

FYI - I spoke to someone at nr racing yesterday & he mentioned most of the 240 & 270 parts will interchange with the 301. This will be interesting to see where the market goes on this one (or if it does).

PS nice green ride !
 
R

Ratchet

Member
#5
#5
Good to know, I am leaning more towards the engine you have.

Did you have to grind the head a bit to get the torque converter to fit ?

What flywheel did you use (if you don't mind) ?

When I do teh build, I plan on adding an air filter, and making a custom pipe to go out the back under the seat (I have to see if there is anything I have to do the carb so I don't do something stupid like lean it out & burn it down), but letting any engine breathe a bit better can't hurt.

Thanks for the feedback.
 
B

BusaBug

New Member
#6
#6
I had to grind and cut the TC back plate. I put the adjustable gx390 carb on it and tuned it.

I used the forged flywheel that bolts the the gx series of engines, and did 6 degrees added timing.
 
X

X"N

New Member
#9
#9
BusaBug said:
I had to grind and cut the TC back plate. I put the adjustable gx390 carb on it and tuned it.

I used the forged flywheel that bolts the the gx series of engines, and did 6 degrees added timing.
Click to expand...
Got any pictures on what you did to the TC back plate to fit?
 
Raskin

Raskin

#10
#10
Looks like you used a mb200 / ct200u 50t rear sprocket..I've thought about drilling one to use on a db30 6" wheel b 4..so looks like i could if wanted ..using a 420 10t clutch yielding 5 to 1 ratio..i just like 420 chain..i know the resistance more..but 420 hardly ever comes off...hmm..that thing a beast..nice job. :thumbsup:
 
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