RE: Engine Knocking

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RE: Engine Knocking

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RE: Engine Knocking - 12/10/2007 11:17:17 PM

SpiritRR

Posts: 2289
Joined: 8/3/2007
From: the Paddock
Status: offline

Okay, yes, I am a derfus. 37mm is the interior diameter of the crank case--where the bearings that surround the journals sit. The 34mm outside diameter is what you thought, the OD of the journal itself. So if you take the 34mm journal and add a bearing, you're now taking up 37mm of total interior crank case diameter.

So yeah, go with the specs in your book.

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(in reply to 97CBR900RR)

Post #: 16

RE: Engine Knocking - 12/11/2007 6:13:00 AM

97CBR900RR

Posts: 8
Joined: 10/31/2007
Status: offline

Ok well ya that would make sense for it to be 37 mm with bearings but its 37 mm now completly bare with nothing on it.... and i put the plastic gage in and squezed it and it flattened up to good spec. but one of my journals where the bad bearing was got worm down to 36mm. So if i had the crank re- done to spec at 34 mm like the book says wouldn't that make it way too small for my rods considering there assuming to be ok at 37 with the rest?

(in reply to SpiritRR)

Post #: 17

RE: Engine Knocking - 12/11/2007 6:58:15 PM

SpiritRR

Posts: 2289
Joined: 8/3/2007
From: the Paddock
Status: offline

So whoever bored the cylinders and did all the other work stuffed a larger crankshaft in there too right, I mean the OEM size is definitely 34mm, so if yours is 37, then the case would have to have been bored larger too. Are you able to measure the case itself, where the main journal bearings sit. If they're not at least 40mm, then something really stinks.

As far as the one journal being a mm down, I don't know what you could do with it. You're kind of stuck, what with larger cylinders and the other journal sizes. There may be a solution, but it would have to come from someone who does this on a daily basis--and is good at it. Perhaps post in Gen Tech, I know there's some car engine guys, ThirdGenlxi comes to mind (though he does American diesels).

Plus I'm just not getting very good vibes from the story of your engine. As capable as you are, I would seriously consider plunking down for a good, used motor. I see one about every 2-4 weeks on ebay, some that I would really want myself. Prices are decent, anywhere from 500-900, usually closer to six. I would at least think about it before you drive yourself up the wall trying to resuscitate this one.

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Post #: 18

RE: Engine Knocking - 12/12/2007 10:04:51 AM

97CBR900RR

Posts: 8
Joined: 10/31/2007
Status: offline

lol ya i see what your saying. Its just mind blowing and driving me completly insane. The only reason that i don't want to just buy a new motor is because of all the upgrades already done to this one.... But who knows maybe i can sell the upgrades and get enough off them for a used motor. Who knows this is just one huge headache. lol

(in reply to SpiritRR)

Post #: 19