Does this motor from California motorbike look worthy?

GoldenMotor.com

Wevil Kenevil

Well-Known Member
Mar 4, 2022
488
471
63
48
Sack a tomatoes California

PORTED GTZ 3rd Transfer Port Injected Split Port Cylinder

Window Piston

Reed Valve

16mm Race Carburetor

Trued Bottom End with 38mm Rod

For $169.00 I think I'm going to get it if nobody has anything negative to say about it. Sorry for the crappy pictures.
 

Attachments

  • Like
Reactions: fasteddy

Wevil Kenevil

Well-Known Member
Mar 4, 2022
488
471
63
48
Sack a tomatoes California

PORTED GTZ 3rd Transfer Port Injected Split Port Cylinder

Window Piston

Reed Valve

16mm Race Carburetor

Trued Bottom End with 38mm Rod

For $169.00 I think I'm going to get it if nobody has anything negative to say about it. Sorry for the crappy pictures.
I'm going to do it.
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,362
2,052
113
Los Angeles, CA.
It's an OK deal if you can't do the 3rd port & window in the piston yourself.



If you have the skillz to do the mods yourself?, here's what I'd buy...



or buy this kit to have all the extra parts too!

 

Gordy

Member
Oct 13, 2024
49
88
18
East Kentucky
It's an OK deal if you can't do the 3rd port & window in the piston yourself.



If you have the skillz to do the mods yourself?, here's what I'd buy...



or buy this kit to have all the extra parts too!

That ebay engine is a 49mm bore iron sleeve. I've heard good and bad about it. The bad stuff I've heard is soft seize issues mostly. Everything else I've heard it's a great engine after matching the sleeve to the ports in the aluminum.
 

Wevil Kenevil

Well-Known Member
Mar 4, 2022
488
471
63
48
Sack a tomatoes California
Well I pulled the trigger on the deal, I got the race motor And a REAL mz 65 pipe in the box.... for $220 bucks.

I got an extended warranty accident " no questions asked" insurance on both for 3 yrs for$30.

Now I just have to wait for it to arrive...

* Looks out the window like it's going to make it arrive sooner.*

Is it here yet?

I think it will look awesome on my bike, not so much because my bike is so great the fact that makes it awesome is that it's MY bike that it's going on.
 

Attachments

Last edited:

Wevil Kenevil

Well-Known Member
Mar 4, 2022
488
471
63
48
Sack a tomatoes California
Ok this is an honest unbiased fact report on this motor only, as I didn't buy the whole kit. But I'm sure that the throttle and the gas tank and all that kind of stuff is standard issue.

Though the ported cylinder , windowed piston and the balanced crank are good, every other component on it is "factory second" quality.

The bolts are decent, but the nuts and washers are garbage.

The gaskets are ok.

The oz mag and magnet clone seem fit. Time will tell..

The clutch pads are GARBAGE. When I went to remove them, they just fell apart and had no compaction to them at all.

The reed box is crap as is it's hardware, reeds seem ok.

The carburetor is crappy poorly made clone mz style.

The oil seals were lower quality than what I'm used to seeing even on a budget motor and he has the cheaper bearings open on both sides, when what he should have is a sealed bearing on one side next to the oil seal.

If you have the mechanical inclination and money to dump into it to replace all the cheap ass cheesy parts then I say give it a try.

But don't buy this motor and think you're just going to slap it on the bike and head to the races because the way that the bike is modified it will very quickly overpower all of the cheap and cheesy components around it causing it to have catastrophic breakdown before 500 Miles.

I'm changing out the oil seals the bearings the clutch pads the carburetor and Reed box and cylinder head, the only thing that's going to stay the same is the case, cylinder, rings and piston.

My mz65 pipe is coming tomorrow so I will be able to give a review on how well it runs after it gets here.

I think if I were to buy this again I would just buy the ported cylinder and and bottom end and buy all of the rest of the parts elsewhere.

Though I do have to give Zane his props for his friendly prompt answers..

The rest of the review will come when I have the bike assembled.

To be continued...
 

Wevil Kenevil

Well-Known Member
Mar 4, 2022
488
471
63
48
Sack a tomatoes California
My pedal arms won't clear the mz65 pipe... I'm gonna run it without pedals... I finally got it all put together and put on the bike today and it doesn't fit...man...

Oh well time start looking for another bike to put it on!.
 

Wevil Kenevil

Well-Known Member
Mar 4, 2022
488
471
63
48
Sack a tomatoes California
This is a side by side of the geometry of a stock pexmor"100cc" kit Crank ( standard issue) and a trued crank out of a wildcat pk80.

First off is the noticable diff in size. The pk80 looks twice the size and weight. It's thicker and the hole orientation is much broader.

Notice that I said that this was a trued crank and not a balanced crank... apparently there is a difference. Stupid me thought truing and balancing were the same.

You know what a balanced crank is. À trued crank is one that is more precisely built and has stricter tolerances. It's like putting horseshoes on à colt that hasn't been born yet.

Instead of balancing it after it's been made they try to balance it before it is made so apparently a trued crank can also be balanced, which should make it ultra smooth... Right?

A trued crank is a quarter inch thicker the lobes are bigger and you can tell by looking at the pictures it's just bigger all the way around it takes up more space in the case so it stuffs the case.

Just thought I might point that little tidbit of information out so everybody's aware cuz I wasn't.
 

Attachments

Wevil Kenevil

Well-Known Member
Mar 4, 2022
488
471
63
48
Sack a tomatoes California
Post pictures of the problem... I'm sure it can be fixed
Thank you Norm, I will do that as soon as I get it back together.

I decided to change the weak oil seals and the no seal bearings to upgraded ones with the inside seal pulled out because the ones he uses didn't have a shield or a seal on the outside by the oil seal and the oil seals he put in it were cheap and flimsy..... and everybody says they leak because of the back pressure from the reeds so I just went in and changed it before the gaskets had burned on.