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Discussion Starter · #1 ·
Hi Fellas,

thanks for reading. I've got a few issues going on with my engine (I'm onto my second thread in the engine forum and have a couple more to post! Doh!).

First, I am missing one of three dowel/pins on the crankshaft that appear to hold bearings in place.

crankshaft.jpg

#12 original part #90708286000
And what holes do they go into? There appear to be three per bearing.

Secondly, could I be missing one of these dowels/pins in the upper portion of the top crank case? Have a look - two, of three, pins pushing through:

IMG_1596.jpg

IMG_1597.jpg

IMG_1598.jpg

IMG_1602.jpg

IMG_1601.jpg

Okay, this is the part you tell me what to do.

Cheers!
 

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Someone didn't line up the pins and their respective bearings the last time the bottom end was apart... I'm guessing it wasn't shifting properly somewhere along the way before you tore it down. those spots can be repaired
 

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I came across something similar and it turned out the cases were previously sealed without the dowels set into the bearings. I ended up replacing the upper case as it caused shift issues when hot
 

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Discussion Starter · #4 ·
Thanks Dad and Doode! So those are the actual dowels pushed up into the case? How would I go about repairing them?

Thanks Fellas!
 

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You could pull the pins out and tap the cracked piece of aluminum back down, wash thoroughly and then use JB Weld on top of it to keep it from coming loose, or (after pulling the pins out) you could take the upper case and pins to someone and have the spots heliarced to repair the cracked spots
 

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Discussion Starter · #6 ·
That's what crossed my mind to - the JB weld.

Now, are these the missing dowel/pins from the crankshaft? And if so, what hole (or does it matter) do they go in in the bearings?

Thank you once again!
 

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I would NOT JB Weld it.
It is inside the cranckcase and will be flooded with oil.

I would have someone TIG/MIG over the chip.

You would want to do it with the case halves assembled but all the guts removed.
 
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Once the case halves are assembled with the transmission shafts properly in place, there is no stress on the locating pins and therefore no stress on the JB Weld that would keep the cracked piece of aluminum in place. As long as the surface is properly cleaned, oil free and prepared correctly, it should stick just fine. That said, if the blob of JB Weld was to come loose for whatever reason, it would fall to the bottom of the crankcase and stay there like the pieces of rubber and metal filings and other stuff we've all found in our twins after 30 to 40 years of average to poor ownership... meanwhile, the pins would still be in place and the transmission shafts would be as well. The very first one like this I fixed while still in high school was easily as bad as his is, and all I did at the time was align the bearing outer, tap the pin back in place and stake the edges of the crack to keep the pin from lifting out of the open hole after removing the piece of aluminum. The bike was fine for the duration of my friend's ownership afterward
 

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Discussion Starter · #9 ·
Perfect - I have a friend who is an excellent welder. Thanks Dad & Yonder.

Now what about the pins/dowels?
1) what hole do they go into on the crankshaft bearings (3 of them)?
2) how far do they need to extend into the bearing housing?
 

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Discussion Starter · #11 ·
Good to know A-Dad. I'll think I'll get my buddy to weld it up for me - I'm in no rush as I won't have this mess of a bike ready to go until Spring, and I would like to be thorough.

Thanks for the link to the pin location. When I pulled my crankshaft there was one pin in two of the three bearings on the shaft. Each bearing has three holes which it looks like the pin can sit into. I'll try and get a pic up. I guess it may not matter so long as the bearing is held in place. I haven't been able to locate any info in the FSM.
 

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Actually, I think it does matter as one of the holes might be an oil passage that has to line up - but Honda made the holes different sizes so you can't put the locating pin in the wrong place IIRC
 

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Discussion Starter · #13 ·
I think you're right and would make a lot of sense - the bearings need lubrication! I have to take a closer look at them and will get a couple pics up. Thanks Tom!
 

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Discussion Starter · #14 ·
Checked the holes in the crankshaft bearings - two of the three are oil/lubrication passage ways, and one is for the pin. So I am missing one pin - not a surprise really after all I am finding about this engine. Off to source one. Thanks all!
 
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