Yamaha Jog 100cc Dragster

[fabster]

More of the same 188cc Dio :







With his brother :

[808ministroke]

Sorry I know this is not pertinent to your build but it seems as though the centerpiece in those twin cylinders was actually made up of 2 parts if this is correct or even if it's not could you please post any more pictures of that centerpiece you may have again sorry I know it's not related to your awesome build.

[fabster]

No worries, this is entertaining. As long as we post awesome stuff, the thread title doesnt matter

I went back in my archives and those were the best pictures of it. It's vague, I dont't remember :s
Hard to believe it's been already 10 years since it went on sale !

www.scooter-system.fr/news/2111-bicylindre-bidalot.html

www.scooter-system.fr/news/2520-bicylindre-mxs.html


As for the Jog, I'm still currently building the V3, but want to start this thread with V1 to show you the complete build chronologically.

I'll post more infos and pictures soon.

[808ministroke]

THANKS A BUNCH I'm taking notes...

[fabster]

Might as well begin the build thread with Version 1, with 2Fast 100cc.
So there it is, Page 3, first post of the project 

The frame comes from a friend who was selling his MHR Team1 LC Jog. This pic is from 2014 (already !)








The Jog frame before surgery.



First iteration had a Jog front fork, lowered and rigid.



I made small bushing for the custom engine mounting points on the frame, to get rid of the subframe.









That's the spirit !

[fabster]

Reception of a 10" rim and Pirelli Angel scooter tire



First Mock-up

[fabster]

On his 2 feet !



I'll be using the same Aerox radiator that my friend chose, with a new gloss black paint

[808ministroke]

I have the exact same radiator and one of my bikes mounted on the front outside of the panels I was using for A77CC I'm guessing that that radiator would not be sufficient for a 100 CC engine unless it was only for short drag races which maybe your whole purpose, That radiator would not be sufficient for A Daily driver of the same engine correct?

[fabster]

Jan 12, 2024 4:40:08 GMT -5 808ministroke said:

I have the exact same radiator and one of my bikes mounted on the front outside of the panels I was using for A77CC I'm guessing that that radiator would not be sufficient for a 100 CC engine unless it was only for short drag races which maybe your whole purpose, That radiator would not be sufficient for A Daily driver of the same engine correct?

With that kind of power, you're not WOT all the time. When riding normally, this is not really an issue. But the lack of airflow in traffic is.
An electric fan help, but it requires quite a bit of power that we don't have with internal rotor ignition, in order to have enough CFM.  That's why we went with big dual radiators on the street, and would not build any setup with less then that for safety. 



Drag race, you're right, the Aerox radiator is enough. 
But the smaller radiators from Gilera Runner are too small, even for that application. An RT70 was almost overheating with the latter.

[fabster]

Opening for the Stage6 / R&D Italia admission kit





My friend made a spacer for the 47mm crank on the Zuma engine. The existing spacer fits on european horizontal crankcase that have a different bolt pattern. We then did the opening for the cylinder skirts



Stock vs 2Fast

[billwill]

Clean! Did you do that by hand? What a drastic size difference.

[808ministroke]

Those are some really good pictures thank you for sharing those with me and everyone.
I have been curious for quite some time about porting the intakes of minerally engine cases, And this is the first time I was able to see pictures of what exactly that would look like which gives me the confidence to do it myself In the picture it looks like in a spot the intake actually was opened up to the point where there was a opening in the case is this my imagination or did you have to JB weld or seal that some way after opening it?
Yes please share with me the measurements that you open the intake 2 as well as what reads you are planning on using looking really good my friend!

[fabster]

The intake track was on the milling, while doing the opening for the bigger crankshaft.

Ports matching is by hand. After multiple setups over the years, I match the cylinder and remove very little material other then that.

This is the intake, except that one is facing rear. I bought that one first, then when making the frame realized that I needed the front facing version. I still got this rear facing version for sale, if anyone needs a great intake setup

This setup is different because the reedblock is clocked 90 degrees compared to an horizontal reeedblock. That's why there is a big hole in the crankcase. I used an Epoxy named Tech Steel to fill. The MXS intake is the other best intake for Mina Hori engines.

[fabster]

Here's some more
I used a die grinder.

[fabster]

Some more picture of the engine build