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Enthusiasts from around the world dedicated to the preservation and ritual flogging of the infamous Kawasaki 2-stroke Triples
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PostPosted: Sun Sep 09, 2012 12:43 am 

Joined: Thu Jun 09, 2011 2:00 am
Posts: 1009
Location: Southern Ontario, Canada
Early H1 (and possibly all H1 series):
Check your frame for crack/broken front down tubes. The crack starts at the very sharp intersection on the top side of the FWD upper engine mount bracket and propagates through the bracket doublers and eventually through the tube itself. Found my RH down tube completely broken and the LH cracked 1/2 way through. :shock:

Had the LH tube failed completely the frame would bend like a wet noodle while riding and I doubt I'd be alive :(



Here's the fix I came up with:
Frame repaired by grinding deep V groove in cracked/broken areas (through reinforcing brackets and well into parent 3mm thick mild steel tubing). This notched butt joint area was subsequently built up with weld. Spare crankcase bolted in to frame to act as jig.

6in long .095in wall 4130 half tube "patch" with parallel 30 degree scarfed ends formed and welded on opposite side (of engine mount brackets) of down tubes across completed above weld. Vertical welds of patch tied into existing engine mount/doubler bracket welds and parent tubing...

Area gently re-heated to dull red to relieve any built in stresses during welding and allowed to cool slowly.

Will smooth/radius the sharp edges of the brackets to help prevent re-occurrence of cracking in the future...


PostPosted: Tue Jan 29, 2013 7:32 pm 

Joined: Fri Jul 15, 2011 6:39 pm
Posts: 124
Location: Pittsburgh,Pa
Might wanna check the engine mount shims. I think 73 and up had them but before that they didnt use them. If its not a tight fit excess vibration can damage the frame and make for excess vibration in the ride also.

Chicken strips are for kids.

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