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Old 17 August 2007, 07:42   #41
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once the crank is welded on the Hot-Su you can lose the rev limiter, and she will pull to the 7's and your hull would be much faster.
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Old 18 August 2007, 08:37   #42
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Not wishing to steal fast fred's thunder and also not knowing Tohatsu engines you might wonder why I'm replying here but we used to do this to motor bike engines years ago.
The crank pins are a push fit into the crank throws and they can move under stress. This can allow a bit of longitudinal flexing but mostly it can allow a bit of rotation of the pin within the crank throw and this, in turn, puts the main bearing journals slightly out of alignment and, consequntly, out of balance. The solution is to weld the end of the pin to the crank throw as per fred's photo. It's a good idea to put the crank between centres in a lathe and use a DTI to check the journals are aligned before welding them. Judicious use of a copper mallet can align them.
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Old 19 August 2007, 10:02   #43
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that is all drag bike crank Guys work, he is magic with a brass mallet and a chizil,
he runs it out before the weld and after, two "Y" up rights are my first choose, then the lathe, none have ever failed, no mater how hard ya crank them.
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Old 24 August 2007, 08:01   #44
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some Yama 50, she got the welded crank, with 70hp carbs

no revlimiter
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Old 24 August 2007, 08:06   #45
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closer to them carbs

and thumpin in the small tank
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Old 24 August 2007, 17:28   #46
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Fred - have you got any video of your race engines running? I'd love to hear and see them modded and without the rev limiter
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Old 27 August 2007, 23:00   #47
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they don't hang around long,once tested, they are on thare way to ware ever.
that ones runnin, turnin slow, the camera cought the fly wheel still,
i'll see if i can get a clip of my moda on me hull.
till then, we gots a shot of a Fast Fred Super Stinger, bumpin on the stand
check the fly wheel

and a vary rare CC FT.

with12 custom venturi carbs cuzz you gots to have them
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Old 29 August 2007, 01:13   #48
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Quote:
Originally Posted by fast fred View Post
some Yama 50, she got the welded crank, with 70hp carbs

no revlimiter



Can 70 hp carbs be bolted right up to a Yamaha 40/50 hp outboard, or is alot of fabrication involved?
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Old 29 August 2007, 06:41   #49
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bolt right on, should set the crank for the 70 carbs, needs a 50hp exhaust pipe
or tuned pipe, you gots to re jet them.
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Old 29 August 2007, 10:16   #50
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I think my Yammie 40 might be due for a Dr. Jekyll to Mr. Hyde conversion.
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