First Build

The chains are loose. The one from the output drive sprocket to the 17 T jackshaft sprocket can be tightened by sliding the engine along the holes in the mount plate but I hit the end with one of the bolts so I can't move the engine further toward the handle bar unless I mod the mount plate and drill new holes. This is a SBP 4 stroke shift kit.

Also did anyone blow out their nexus 3 internal hub. I don't think they are designed for motors.

 

[rananthan3]

The only thing left is the petcock, loctite, and proper torquing. If it falls apart, I can put it back together.

 

[wheelbender6]

Hang in there. That motorbike is going to be a looker. Other members have used nexus hubs with good results. I have only used one on a bike that wasn't motorized.

 

[Leroybrown420]

Nice. Are you going to powder coat your frame? I did mine flat black.

 

[KCvale]

Nice looking build!

The output drive sprocket to the 17 T jackshaft sprocket can be tightened by sliding the engine along the holes in the mount plate but I hit the end with one of the bolts so I can't move the engine further toward the handle bar unless I mod the mount plate and drill new holes.

Correct.
You need to modify your base and it is not uncommon.
Heck, I pretty much make all my own 4-stroke shifter bases though the SBP shift kit is a pretty good base.

Usually this involves welding a tab at the end of the front U plate the width of a muffler clamp that will fit the downbar.

The muffler clamp gives you a 360 degree grip and flat spot for mounting to.

Also did anyone blow out their nexus 3 internal hub. I don't think they are designed for motors.

No, have you toasted an internal shifter?
I have dozen or more out there and not a single failure I know of.

I absolutely love internal little 3-speed hubs for shifting bikes, the above example has a Nexus, the last one I did was Strumey Archer.
These is a simple beauty to fat chain going to single sprocket in perfect alignment.

Here is a tip for your right side chain tension...
Put a tension wheel on the base plate or via a spring loaded derailleur sprocket to adjust that so you don't need to mess with your base when it's in perfect.

Just be sure to always put any tensioner on the return side of chain drive, not the drive side, that has all the force.

 

[rananthan3]

I am comfortable with the color. I will look into the right hand side chain tensioner which will be useful as the bike ages. Slack in the chain is a big source of performance degradation and mechanical failure.

 

[KCvale]

I will look into the right hand side chain tensioner which will be useful as the bike ages.
Slack in the chain is a big source of performance degradation and mechanical failure.

Actually, the initial 'aging' can be had in the first ~10 miles of operation, that's why I have to keep a helper just to go ride the thing around for a couple miles at time, and then bring it back for adjustment.

After ~10 miles things get easy to maintain and adjustment minimal.

Sure you can use a spring loaded tensioner so you don't have to turn a wrench but there pros and cons to that too.

For me that depends on many factors from the power type to the drive train, but chain and sprockets wear a bunch to first 'mate' much like rings in an engine, but it's simple from there and a fixed pulley is great for that.

 

[Leroybrown420]

"that's why I have to keep a helper just to go ride the thing around for a couple miles at time"

That sounds like my kind of job. Nothing but the gravy.

 

[Saddletramp]

I have three Honda GXH 50 motors just sitting here on my shelf. Is that a store jack shaft mount? If so Where did it come from? It's pretty. You have done such a nice job. I have three Schwinn OCC bikes I would love to put a 4 stroke on.

 

[rananthan3]

I have three Honda GXH 50 motors just sitting here on my shelf. Is that a store jack shaft mount?

The jack shaft mount comes with the 4 stroke shift kit sold by Sick Bike Parts:

http://www.sickbikeparts.com/catalog/