Who sells a 7G Ghost Racer transmission today

[michael whiteman]

Chainlube & DieselTech: I measured my bike today and found this to be interesting. The 100mm (3.930) distance you marked on your drawing above is actually 106.24mm (4.183) on my straight shaft engine. All GruBee's engines have tapered shafts. I was under the impression that the 4 transmission mounting holes were spaced the same on both style motors. I know nothing about the Honda 50. Can anyone confirm this ? If my findings are correct the interchangeability of transmission styles is next to none.

 

[michael whiteman]

DieselTech: We discussed earlier about possibly putting a 4G 100T pulley on my 7G trans. even though Don G. says it won't work. My output shaft measures .591 with a keyway width of .160 How does this compare to your 4G pulley ?

 

[DieselTech]

Chainlube & DieselTech: I measured my bike today and found this to be interesting. The 100mm (3.930) distance you marked on your drawing above is actually 106.24mm (4.183) on my straight shaft engine. All GruBee's engines have tapered shafts. I was under the impression that the 4 transmission mounting holes were spaced the same on both style motors. I know nothing about the Honda 50. Can anyone confirm this ? If my findings are correct the interchangeability of transmission styles is next to none.

Ok I did some measuring, the true 50cc honda gxh50 is 105.8mm center to center on a straight shaft engine. Here is a pic of a double chain 6:1 gearbox for a hausheng 142f taper shaft engine & it is 100mm on the dot. I cant believe they made two different bolt patterns from the straight shaft to taper shaft engines.

 

[michael whiteman]

I got a TAV & a flat briggs on a all hand built mini chopper with a 60 tooth #35 chain sprocket I can easily run 48mph. Keep in mind the there is not 1 thing stock on my flathead briggs thou.

This sounds pretty scary to me ! But here again, the Brigs is a low rpm engine, like the Predator, so we're not really comparing apples to apples. If you had a 6800 rpm engine on this mini and you wanted a top speed mid thirties you would need a lot larger sprocket than 60, correct? A larger sprocket might create clearance problems with the frame. Don't know ? Just thinkin' out loud.

 

[DieselTech]

This sounds pretty scary to me ! But here again, the Brigs is a low rpm engine, like the Predator, so we're not really comparing apples to apples. If you had a 6800 rpm engine on this mini and you wanted a top speed mid thirties you would need a lot larger sprocket than 60, correct? A larger sprocket might create clearance problems with the frame. Don't know ? Just thinkin' out loud.

You forgetting about the variable part of the torque convertor, it goes from a under drive to a overdrive in respect to engine rpm.

 

[DieselTech]

The only thing minus mounting modifications, that I would be worried about is if our little 50cc huasheng engines have enough power to actually make the torque convertor work properly.i think you & some1 else had a thread about the 79cc engines & torque convertors.

 

[DieselTech]

DieselTech: We discussed earlier about possibly putting a 4G 100T pulley on my 7G trans. even though Don G. says it won't work. My output shaft measures .591 with a keyway width of .160 How does this compare to your 4G pulley ?

Yes it's a 15mm shaft with a 4mm keyway on my 4G tranny. So with my numbers converted it comes up to .5905" on the shaft & .160" on the keyway. Or 15mm with a 4mm keyway. I'm saying pulley is the same, need to check edge of pulley to tranny mounting plate to verify pulley offset is the same.

 

[michael whiteman]

You forgetting about the variable part of the torque convertor, it goes from a under drive to a overdrive in respect to engine rpm.

No I didn't. I like to think about the ratios as minimum and maximum. One would need to know the effective diameter of the drive pulley when it is in, what you call, the "overdrive" position. With this you could calculate the bike's top speed. Any ratio lower within the torque converter will just produce a slower speed with more torque.

 

[DieselTech]

No I didn't. I like to think about the ratios as minimum and maximum. One would need to know the effective diameter of the drive pulley when it is in, what you call, the "overdrive" position. With this you could calculate the bike's top speed. Any ratio lower within the torque converter will just produce a slower speed with more torque.

I have the ratios somewhere in my paper work, I'll see if I can locate it.

 

[michael whiteman]

Here is a cross section of my pulley and a pic of the backside. How does it compare to yours ? I think you have a black freewheel in the center of your pulley, right? That might present an offset clearance issue. Notice I had to remove the black retainer ring on the back of my pulley because it was kissing the bell. Belt still tracks perfectly.