EZGO With Honda GX630 Engine Conversion and BIG Lift Kit

ez87twin

New Member
Hey all, talked to randy @wicked carts and he said to look for Nubs (are you outthere somewhere)?
Just did a engine conversion on a 87 EZGO, new honda Gx630 v-twin 688cc 20.6hp 35ft pds torque, new comet style 780 drive, new 36 ezgo driven, new ultimax 50hp belt.

New wheel bearings all around, new 22x11x8 swamp fox tires, BIG 8" lift kit, 8" wider, 94 ezgo diff 8" back from stock placement, 6-1 high speed gears.

Direct to carburetor throttle linkage no governor. Went from 23mph to 30mph w/gear change 12-1 to 6-1 very very strong bottom end could climb trees but not much top speed.

Runs GREAT very car like very slow to 30mph but i think i should be able to have more top end?
Anybody? NUBS i heard you are the man!
thank you all for your time !!!!!!!
 

Nubs

Cartaholic - V.I.P.
A fella would need to know a little more, whats the rpms at 30 MPH? Is the belt the right length? I'd run it on some jack stands and see if the clutches shift all the way out, when the belt is to the top of the drive clutch is it riding all way down in the driven?
The GX630's were really choked down to pass CA emissions
 

MrWicked

Cartaholic - R.I.P.
Hey nubs he doesnt know the rpm but hey says it sounds like hes floating the valves at top speed.., the new honda is more cc but with less power?
 

dirtysouth

Cartaholic - V.I.P. Sponsor
Belt ain't comin' all the way up and one or both clutches are set wrong if it's climbing slow. Move the engine closer to the rear end and see if that helps.
 

ez87twin

New Member
hey nubs thank you thank you for your input!
[email protected]
4500 red line
it starts to valve float or rev limit or ?
yes on jacks in runs out down in the driven
up in the drive
set up belt for original 11 1/2" shaft to shaft i found a belt 1/4" shorter
the belt has just a little gap maybe 20 thous @ drive
push the gas just barly and she go's --let off and it stays put
worked on belt deflection and alignment
i've went about 600 miles 2 of the trips were 120 miles each(garmin gps)
funtionality is just about perfect hill climbs, mud,just cruising
but hear of a lot of people doing just gear change on stock motors getting 35-40mph
am i lust asking for to much?
any performance hope for the new honda Nubs
thank very much!
 

Nubs

Cartaholic - V.I.P.
a fella has to have a tach in a conversion like that more cc's don't always mean alot, even a aftermarket air cleaner can cause the hp to drop off on smog motors.
 

Nubs

Cartaholic - V.I.P.
30 on 22's and 6:1 @ 4K is a little off but not much :twocents: the math thinkers may say different.
 

MrWicked

Cartaholic - R.I.P.
i know nothing about the new honda

the older 24hp 1180 clutch stock gears 25" tall tires was 33-34- mph at 4800 rpm
 

mtwain69

New Member
87 ezgo new honda Gx630 twin 688cc 20.6hp 35ft pds torq new comet style 780 drive new 36 ezgo driven
new ultimax 50hp belt new wheel bearings all around new 22x11x8 swamp fox tires 8" lift 8" wider 94 ezgo diff 8" back from stock placement 6-1 high speed gears direct to carb throttel linkage no gov. went from 23mph to 30mph w/gear change 12-1 to 6-1 very very strong bottom end could climb trees not much top speed runs GREAT very car like very slow to 30mph but i think i should be able to have more top end? anybody? NUBS i heard you are the man! thank you all for your time !!!!!!! rev kit and cam and you'll be doin 45 easy
 

rvkersh

New Member
Your slow top speed is the comet 780 clutch. It is a good clutch,but it is only 7" diameter, your stock ezgo clutch is 7 1/2" diameter. When I did my v-twin swap I used the 780, my top end was slower than stock on flat ground. I changed to the cvtech 06 clutch which 7 1/2" diameter, problem solved. Honda GX620, cvtech06, 8:1 gears, 23 in. tires, 5000 rpm, 38 mph on flat ground. The comet 1180 is 8".
 
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