71 kawasaki G3SS with Honda motocross motor (winter refresh)

[m in sc]

While the rivet counters out there will absolutely CRINGE when they see this, I can assure you, a stock G3 is pretty worthless restored and kind of a crappy bike overall. That being said, about 9? yrs ago i got a 71 from a buddy of mine. it was 'ok'. transmission was a nightmare, and really didn't do anything well except look cool.

this was it in relatively stock configuration.

after about 2 years of ownership, a motor refresh, etc, i decided to up the game a bit and add an easily rebuildable, parts a plenty mini 2 stroke motor, so i went with a CR85 motor. they put out over 2x the HP, have a 6 speed, and are liquid cooled. only down side, no lighting system. Si i ran it total loss battery lights etc and it was fine. I built some rearsets using FZR600 ones as abase, converted the front from a drum to a disc, utilizing a GT185 wheel, and yamaha RX50 disc and caliper. i made the caliper mount and welded it onto the stock G3 forks.

still relatively stock, i decided to run a full race fairing. there was a LOT of mods done to this. its a reproduction kriedler 50cc racing fairing, and a gustafson windscreen. not cheap, so i immediately cut it up, and had the stock color paint matched.

it was at this time i did the motor swap. (you can see it behind the fairing)

for years i kept it this way. finally about a year and a half ago the rod bearing finally went. now, keep in mind i think its 22 or 23 hours int he service to replace them, this had been together since 2014. and yes, i painted it kinda crappy to keep it all matching 'like a guy that lived out of his van in 1978 raced it'.

so fast forward to 2022. I dragged it home and rebuilt the motor, including a new crank. also added a 'bills pipe' aftermarket chamber.

tidied up a bunch of other stuff as well.

so, back to the 'total loss electrical' running thing. Since this only affected lighting, it didnt affect performance. and NO ONE makes a lighting kit for a cr85 motor. I mean, why would they?

But i needed one. so i contacted HPI ignitions (who i have used before) and they put together a CDI w lighting kit for me to do this.

2 weeks of back and forth on emails and they shipped it out. here we go.

stock honda cdi:

new HPI stator and plate:

I had to modify it a bit to get it to fit the case: (yes the windings were removed for lathe work)

verify max adv on stock unit:

remove and replace:

made 12v battey holder (this things tiny, 0.8 ah) . vr under it, coil and cdi box on other side of bike (where stock 6v battery used to reside)

wanted to add a gps speedometer so picked up one off ebay. made a bracket (also water temp lower left)

mounted:

gps antenna on fairing brace during mock-up:

and done. note new radiator as well.

and yes, its 100% road legal, insured and plated. will also do wide open with me on it right at 80 mph. can cruise at 60 really well, and is an absolute riot. you can power wheelie it in 3rd gear.


Hope you all enjoyed it. if it offended anyone becaus ei cut up a vintage bike... well, theres a side note.

My buddy Jimmy has a 70 G3TR, the 'bushmaster' version of this bike his mother bought brand new in college in CA. It is now running on my original motor out of this, and all the stock stuff i took off has gone to him to keep that one alive & restored. His mother is still around and that bike is still registered in her name even though Jimmy has it here. Good stuff.

 

[dmonkey]

Two bikes running are more fun than one bike sitting collecting dust and rust. Cool frankenbuild, I especially dig the fairing. How's the GPS speedo working out?

 

[m in sc]

gps works great. def better that what you would expect for.. 50 bucks? smooth and spot on.

2 is great. I have 14 runners. to that's 7x great i guess.

 

[G19Tony]

While the rivet counters out there will absolutely CRINGE when they see this, I can assure you, a stock G3 is pretty worthless restored and kind of a crappy bike overall. That being said, about 9? yrs ago i got a 71 from a buddy of mine. it was 'ok'. transmission was a nightmare, and really didn't do anything well except look cool.

this was it in relatively stock configuration.

after about 2 years of ownership, a motor refresh, etc, i decided to up the game a bit and add an easily rebuildable, parts a plenty mini 2 stroke motor, so i went with a CR85 motor. they put out over 2x the HP, have a 6 speed, and are liquid cooled. only down side, no lighting system. Si i ran it total loss battery lights etc and it was fine. I built some rearsets using FZR600 ones as abase, converted the front from a drum to a disc, utilizing a GT185 wheel, and yamaha RX50 disc and caliper. i made the caliper mount and welded it onto the stock G3 forks.

still relatively stock, i decided to run a full race fairing. there was a LOT of mods done to this. its a reproduction kriedler 50cc racing fairing, and a gustafson windscreen. not cheap, so i immediately cut it up, and had the stock color paint matched.

it was at this time i did the motor swap. (you can see it behind the fairing)

for years i kept it this way. finally about a year and a half ago the rod bearing finally went. now, keep in mind i think its 22 or 23 hours int he service to replace them, this had been together since 2014. and yes, i painted it kinda crappy to keep it all matching 'like a guy that lived out of his van in 1978 raced it'.

so fast forward to 2022. I dragged it home and rebuilt the motor, including a new crank. also added a 'bills pipe' aftermarket chamber.

tidied up a bunch of other stuff as well.

so, back to the 'total loss electrical' running thing. Since this only affected lighting, it didnt affect performance. and NO ONE makes a lighting kit for a cr85 motor. I mean, why would they?

But i needed one. so i contacted HPI ignitions (who i have used before) and they put together a CDI w lighting kit for me to do this.

2 weeks of back and forth on emails and they shipped it out. here we go.

stock honda cdi:

new HPI stator and plate:

I had to modify it a bit to get it to fit the case: (yes the windings were removed for lathe work)

verify max adv on stock unit:

remove and replace:

made 12v battey holder (this things tiny, 0.8 ah) . vr under it, coil and cdi box on other side of bike (where stock 6v battery used to reside)

wanted to add a gps speedometer so picked up one off ebay. made a bracket (also water temp lower left)

mounted:

gps antenna on fairing brace during mock-up:

and done. note new radiator as well.

and yes, its 100% road legal, insured and plated. will also do wide open with me on it right at 80 mph. can cruise at 60 really well, and is an absolute riot. you can power wheelie it in 3rd gear.


Hope you all enjoyed it. if it offended anyone becaus ei cut up a vintage bike... well, theres a side note.

My buddy Jimmy has a 70 G3TR, the 'bushmaster' version of this bike his mother bought brand new in college in CA. It is now running on my original motor out of this, and all the stock stuff i took off has gone to him to keep that one alive & restored. His mother is still around and that bike is still registered in her name even though Jimmy has it here. Good stuff.

You have some mad skillz, my friend. Well done!

 

[SneakyDingo]

My Dad owns or owned a Model 50, which most of those were cut up to make the Triton combination bikes. I'm also pretty familiar with the Sil80 (Silvia - Nissan 180SX) Frankenstein creations in Australia.

You took something of almost no value and made it your own, something I very much struggle to do outside of functional reasoning (I mean, shit, this is why I own a CT125). This is super impressive, bravo. I really like the color scheme too.

 

[m in sc]

thanks. Its fun for sure. still going strong.

this is it last month, 3 week or so ago, my buddy adam taking it out at a bike night. He didnt get on it until a few minutes later after it warmed up. even with him or me on it it will wheelie in 1 & 2 and come up in 3rd under power. (im 210, hes 230 lbs).

 

[SneakyDingo]

Back in the day one of the guys that was in my streetbike group had one of these: a Cagiva Mito 125. Darn thing went like a bat outta hell, and was tons of fun.

He eventually sold it after he started meeting too many new people on it, mostly police.

 

[dmonkey]

Sounds great, I can almost smell it.

Back in the day one of the guys that was in my streetbike group had one of these: a Cagiva Mito 125. Darn thing went like a bat outta hell, and was tons of fun.

He eventually sold it after he started meeting too many new people on it, mostly police.

I had a Cagiva Tamanaco with the same motor as the Mito 125. They're a blast until you need to use Google Translate to order parts from Italy or the Netherlands and then wait several weeks for them to arrive. The CT125 is what ended up replacing that bike for me, it's not the same amount of fun as braaping around on a weird Italian dirtbike, but it is practical enough that I'm happy with it. Not only do you meet cops on 2-strokes, but they also help break the ice for meeting your neighbors Neighbors are really happy with the CT125 replacing the Tamanaco.