swap hoot gearbox for skyhawk

[dougsr.874]

I'm still trying to swap out the hoot gearbox for a skyhawk...the supplier of the skyhawk left out the bolts and bushings, I finally got them from him today....MY PROBLEM IS: the bolts he sent will not screw into the HuaSheng engine....and the old hoot bolts are too long & very poor quality....I know I've seen this discussed on here somewhere but I have looked in vain to find it....Does anyone know what to buy What will work...are the bolts mm or sae, type of thread, etc.....PLEASE HELP

 

[ocscully]

The bolts should be SAE 1/4 - 28 tpi Fine Thread. At least the ones for the Honda GXH50 are. As to length I can't ofer any advice there other than I believe that you need two different lengths as there are two shorter ones that mount the inside half of the gear box and I believe these need to have heads tht fit into counter bores. And then you need two longer ones that go thru the outside half of the gearbox.

ocscully

 

[dougsr.874]

Dear Oscully, thanks so much for your help...weird why there are SAE threads here when everthing else appears metric...hope the HuaSheng & Honda are the same

Doug in Florida

 

[ocscully]

I agree it does seem odd? It was explained in another thread that the reason is/was that the motor was designed to fit american made clutches and various apperatus (generators, power washers, etc.)? The end of the crankshaft/output shaft is also 1/4-28 Fine thread as well, but every where else thrreads are metric.

ocscully

 

[dougsr.874]

Dear Oscully, finally got the skyhawk attached and remounted the engine...started it up and the problem is: when the clutch is engaged it is a very violet act, and the engine vibrates very badly, I put axle grease on the gears before starting, but no gear oil, I have just bought some heavy gear oil and am going to try that....Any thoughts???????????????BTW., the mounting bolts on this Hua Sheng are 9 mm....fine thread,,,I tried the quarter in. sae and they were too big......

 

[ocscully]

Doug,

I'm sorry I don't have anything to offer about the clutch problem. Perhaps Houghmade or Irish will be able to comment with their thoughts as they have experience with the Grubee clutches and gearboxes. Also thanks for the feedback on the mounting bolts on the Clone motor. Since you said that the 1/4 in. were to large I'm guessing when you indicated 9mm you meant 6mm as 9mm would be closer to 3/8 in. where 6mm would be slightly smaller than 1/4 in. Do you have the thread pitch stated as a # by any chance, (1 or .75)? My guess is it is .75 which I believe is the designation for Fine Metric threads for a 6mm bolt.

ocscully

 

[dougsr.874]

Oscully, you're right, the bolts are 6mm and not 9, sorry I don't know the pitch...I think I may have left a spacer out of the Skyhawk, I found and have put the half inch spacer on the outside of the final drive gear...too cold & dark to try it now....Do you know where there is an exploded view of the Skyhawk?...I have not talked to the other two guys, if you do please ask them to comment.....Thanks again for your help.....Doug

 

[ocscully]

Doug,

The Grubee web site http://www.grubeeinc.com/ has some cutaway drawings of the gearbox. Click on Stage III frame mount and scroll down a bit and you will see them as well as some pretty good photos of the installation process/steps for the gearbox. Other than these I'm not aware of any other exploded view of the gearbox.

I just spent some time reading the information on the Grubee installation instructions. In step #2 they indicate that there is a version of the clone motor that has an under sized output shaft (15mm dia. instead of 15.8mm dia.) Are you able to check accurately (with a caliper) the dia. of the shaft of your motor? Also take note of the possibility of needing to file down one of the crankcase bolts to get the gearbox to seat properly to the crankcase of the motor?

ocscully