'Flyin' Dutchman'
05-15-2004, 03:10 PM
Hey!
I promised some of you to post the story about the broken drive shaft from my Hunt mag, and how we fixed it...
BTW. I never got an e-mail back from the Joe Hunt company... I might try to contact 'em again.
You might remember these pics, of the broken shaft...
http://img64.photobucket.com/albums/v194/75hotrodder/breakdown_1.jpg
http://img64.photobucket.com/albums/v194/75hotrodder/breakdown_2.jpg
Why did the shaft break..? Well, what we think is that it had too much vibration... The whole mag, which is pretty heavy, is bolted onto the aluminium adapter plate, with two tiny 6 millimeter bolts. They are bolted into the adapter plate, which has thread in it.
We changed this to 8 mm bolts, with nuts on the back... Actually, when we did this, we ran into another problem. The heads of the bolts are actually too big (see pic), and we weren't able anymore, too advance the mag enough. That way, I couldn't even start the motor.
http://img64.photobucket.com/albums/v194/75hotrodder/006.jpg
What did we do to solve this. I already had a new shaft, made from a 3/8 allen wrench, which was perfect, but since it all didn't work, we took that one out.
We repositioned the adapter plate (there's two positions available), and made a new shaft (by hand, with a file), from hi quality steel, which was actually offsetted about 8 degrees, so that the whole thing was already in a pretty much advanced position when you mount it.
http://img64.photobucket.com/albums/v194/75hotrodder/003.jpg
http://img64.photobucket.com/albums/v194/75hotrodder/004.jpg
http://img64.photobucket.com/albums/v194/75hotrodder/005.jpg
We adjusted the mag according to Joe Hunts specs, 5/16 before TDC, and the bike started on the first kick!!
Advanced it a bit more, and I was rolling again!
I went to some more trouble, since I couldn't get the bike to run faster then about 60 MPH... I though there was a problem with the advance unit, in the mag. I've been testing and messin' around with all kinds of stuff in the last days... With air filters, without air filter, adjusting main needle jets, needle settings, advancing, retarding...
And today... I managed to haul ass through first, second, and third... I'll tell you... IT FUCKIN' SCARED THE SHIT OUT OF ME!! It runs like hell now... I got almost thrown of the seat shifting from 1st to 2nd and from 2nd to 3rd! Only in fourth there's a lack of power, but it's good to cruise with around 50 - 55 MPH in third... We're going to a chopper show tomorrow and when we come back, we're gonna adjust the needles again, so it'll get a little less fuel, and I hope it runs good in fourth then too...
The plugs read good now, and I see that there's no excessive exhaust smoke on the frame and inner pipe anymore... That means the mixture is a lot better now...
http://img64.photobucket.com/albums/v194/75hotrodder/001.jpg
When I was riding the bike today, at some back road, going through the gears like a madman, it reminded me to last years Antique Nats... There was a guy named John, maybe some of you know him, I met him a lot of Southern Cal events... Really swell guy, and he always races his Trump at the Nats... Somehow I really like his bike and today remembered me seeing him racin'down the strip there...
http://img64.photobucket.com/albums/v194/75hotrodder/johnstrump.jpg
I promised some of you to post the story about the broken drive shaft from my Hunt mag, and how we fixed it...
BTW. I never got an e-mail back from the Joe Hunt company... I might try to contact 'em again.
You might remember these pics, of the broken shaft...
http://img64.photobucket.com/albums/v194/75hotrodder/breakdown_1.jpg
http://img64.photobucket.com/albums/v194/75hotrodder/breakdown_2.jpg
Why did the shaft break..? Well, what we think is that it had too much vibration... The whole mag, which is pretty heavy, is bolted onto the aluminium adapter plate, with two tiny 6 millimeter bolts. They are bolted into the adapter plate, which has thread in it.
We changed this to 8 mm bolts, with nuts on the back... Actually, when we did this, we ran into another problem. The heads of the bolts are actually too big (see pic), and we weren't able anymore, too advance the mag enough. That way, I couldn't even start the motor.
http://img64.photobucket.com/albums/v194/75hotrodder/006.jpg
What did we do to solve this. I already had a new shaft, made from a 3/8 allen wrench, which was perfect, but since it all didn't work, we took that one out.
We repositioned the adapter plate (there's two positions available), and made a new shaft (by hand, with a file), from hi quality steel, which was actually offsetted about 8 degrees, so that the whole thing was already in a pretty much advanced position when you mount it.
http://img64.photobucket.com/albums/v194/75hotrodder/003.jpg
http://img64.photobucket.com/albums/v194/75hotrodder/004.jpg
http://img64.photobucket.com/albums/v194/75hotrodder/005.jpg
We adjusted the mag according to Joe Hunts specs, 5/16 before TDC, and the bike started on the first kick!!
Advanced it a bit more, and I was rolling again!
I went to some more trouble, since I couldn't get the bike to run faster then about 60 MPH... I though there was a problem with the advance unit, in the mag. I've been testing and messin' around with all kinds of stuff in the last days... With air filters, without air filter, adjusting main needle jets, needle settings, advancing, retarding...
And today... I managed to haul ass through first, second, and third... I'll tell you... IT FUCKIN' SCARED THE SHIT OUT OF ME!! It runs like hell now... I got almost thrown of the seat shifting from 1st to 2nd and from 2nd to 3rd! Only in fourth there's a lack of power, but it's good to cruise with around 50 - 55 MPH in third... We're going to a chopper show tomorrow and when we come back, we're gonna adjust the needles again, so it'll get a little less fuel, and I hope it runs good in fourth then too...
The plugs read good now, and I see that there's no excessive exhaust smoke on the frame and inner pipe anymore... That means the mixture is a lot better now...
http://img64.photobucket.com/albums/v194/75hotrodder/001.jpg
When I was riding the bike today, at some back road, going through the gears like a madman, it reminded me to last years Antique Nats... There was a guy named John, maybe some of you know him, I met him a lot of Southern Cal events... Really swell guy, and he always races his Trump at the Nats... Somehow I really like his bike and today remembered me seeing him racin'down the strip there...
http://img64.photobucket.com/albums/v194/75hotrodder/johnstrump.jpg