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Big Bore Electric Start Problem

Johnny Tran

New Member

Hello guys, I'm new here and I only speak english so please help me if you can. My engine mods are:

UMA 62mm Block
30mm Carb with bigger jettings (not sure what size)
BRT CDI
Vixion Stage 2 Cams
AHM Pipe (newest model)

The problem now is that my bore is so big that it's hard to fire up using the electric starter so I have to frequently kick start but even that's a pain... My mechanics say that it's b/c I'm in high compression but I don't know what this means. Someone please explain to me what I can do so that I may use the electric starter again since I will be getting a full body fairing kit that will cover the kick starter (ie: Will a Racing Ignition Coil help??) Thanks!
 

SPEED RACER

Super Veteran
Hello guys, I'm new here and I only speak english so please help me if you can. My engine mods are:

UMA 62mm Block
30mm Carb with bigger jettings (not sure what size)
BRT CDI
Vixion Stage 2 Cams
AHM Pipe (newest model)

The problem now is that my bore is so big that it's hard to fire up using the electric starter so I have to frequently kick start but even that's a pain... My mechanics say that it's b/c I'm in high compression but I don't know what this means. Someone please explain to me what I can do so that I may use the electric starter again since I will be getting a full body fairing kit that will cover the kick starter (ie: Will a Racing Ignition Coil help??) Thanks!
bro, you have to replace your starter motor with bigger one that can handle up to 250cc.
we have same problem.
 

Johnny Tran

New Member
Ah ok thanks bro! Where can I buy the motor? and how much? Also, will I have any problems with the stock battery if I change to the bigger starter?
 

SPEED RACER

Super Veteran
Ah ok thanks bro! Where can I buy the motor? and how much? Also, will I have any problems with the stock battery if I change to the bigger starter?
in our place here in cebu we have many starter motor ( brand XP starter motor for big displacement engine )
selling price php 1,900.
you can use your stock battery.
 

turbulence

Super Veteran
I advise you to use LOW PROFILE CAMSHAFT bro for easy start. im using CMS camshaft and it is softer to kick than any camshaft a have tried. Kawahara stage2 is hard to start using kick. it is stiff as well as the slectric
 

turbulence

Super Veteran
Low cam has better acceleration and top end. Cms is not much of a low cam. Still 2mm additional valve pocket needed.
 

transporter

New Member
Hello guys, I'm new here and I only speak english so please help me if you can. My engine mods are:

UMA 62mm Block
30mm Carb with bigger jettings (not sure what size)
BRT CDI
Vixion Stage 2 Cams
AHM Pipe (newest model)

The problem now is that my bore is so big that it's hard to fire up using the electric starter so I have to frequently kick start but even that's a pain... My mechanics say that it's b/c I'm in high compression but I don't know what this means. Someone please explain to me what I can do so that I may use the electric starter again since I will be getting a full body fairing kit that will cover the kick starter (ie: Will a Racing Ignition Coil help??) Thanks!
bro much better to use cms cam and i was agree with the suggestion of turbulence. im using also same set up with you but i can use my starter easily fire up. i use only 28mm keihin carb and r9 mugello pipe best for top end. . .
 

docgabby

Super Veteran
Hello guys, I'm new here and I only speak english so please help me if you can. My engine mods are:

UMA 62mm Block
30mm Carb with bigger jettings (not sure what size)
BRT CDI
Vixion Stage 2 Cams
AHM Pipe (newest model)

The problem now is that my bore is so big that it's hard to fire up using the electric starter so I have to frequently kick start but even that's a pain... My mechanics say that it's b/c I'm in high compression but I don't know what this means. Someone please explain to me what I can do so that I may use the electric starter again since I will be getting a full body fairing kit that will cover the kick starter (ie: Will a Racing Ignition Coil help??) Thanks!
sorry to say you dont have any solution except to kick start and get used to it. there aint any aftermarket big starter to handle the bigger bore cranking. unlike with the mio there is. the problem is the crankcase. the recess where the starter goes is too narrow to accommodate a bigger starter. just like MX bikes get used to kicking it till it fires.
Photo0138.jpgPhoto0139.jpg
 

docgabby

Super Veteran
try to lower the compression by putting a 1mm base gasket
rather than giving away that precious compression..dont disable the mechanical compression release on the cam gear. or yet again if there is a manual compression release lever.
 

jchris1124

Super Veteran
rather than giving away that precious compression..dont disable the mechanical compression release on the cam gear. or yet again if there is a manual compression release lever.
usually if we use hi-lift cam we remove the decomp assy.
 

docgabby

Super Veteran
usually if we use hi-lift cam we remove the decomp assy.
the reason the compression release is removed with the hi lift cam is because of the profile of the cam or how the cam is built up and reground. its much easier for camprofilers to build up little but grind more. if you design the cam with sacrificing the compression release then that would best.
 
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