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Discussion Starter · #1 ·
Sorry, I did a search and didn't come up with anything specific to my issue. I have a 1970 CB450 that has been bored to fit the 74mm pistons (roughly 500cc now), K&N pod filters and straight through (no mufflers) CL exhaust. Any idea what I should be running for jets? Currently running stock jets on the stock carbs.

 

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Discussion Starter · #3 ·
Well I haven't gotten to run it much, let alone get it to idle correctly. I followed the Carb setup thread that was posted. I haven't finished my tank bottom yet so I fill the carb bowls w/ fuel, re-attach and then fire it up. I noticed the left carb is running out of fuel way before the right carb is. When I pull the plugs the left is black and the right is clean. I know I'm getting spark, I've checked and re-checked the points and valve adjustment. I'm also getting some popping and a couple flames out of my right cylinder's exhaust tip when I rev up the rpms. Any thoughts? Thanks
 

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Discussion Starter · #5 ·
Well, found out that the right cylinder is not firing consistently. So I think it may be a little of timing and a little of carb adjustment. I checked the gap on the right side points and made sure it's firing on the "F" mark and everything is correct. Gap is at .013". Should I try opening it up to a little closer to the .016" limit? I'll pull my right side carb off and clean it again just to make sure. I would think that it would still be pulling fuel from the carb even if it's not firing.
 

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Sensei
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Changing the gap on the right side points will change the timing!... If they fire EXACTLY at "F" and the gap is within specs, it is fine.....
 

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Discussion Starter · #7 ·
That's right, I should have known that. I'll try cleaning out the carb again and see if that's it. Don't know what else it could be. Left side fires like a champ.
 

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Sensei
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Are the coils/caps/wires suspect at all?.....
 

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Discussion Starter · #9 ·
No, I'm getting great spark (as good as a points system can get) on both plugs.
 

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Sensei
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The flaming in the pipe could be a bad exhaust copper donut.... as for the fuel amounts used up, swap the carbs and see if it changes sides (Chokes will have to be taped open, but shouldn't be too hard without the tank on...)... My hunch is a "hammered in" intake valve isn't opening long/wide enough even though it is adjusted correctly.... Were the old tappets severly "dished" in and are the ones in there now within physical (not adjustment) specs?....Are the "new" rings seated and gaps at 120?..... What's the current compression?
 

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Discussion Starter · #11 ·
Well, would a clogged slow jet cause my problems? :oops: Yeah stupid me. Sorry for wasting your time. It's running like a champ now.
 

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I've seen a lot of that over the years. I've seen a ton of old bikes parked and quickly forgotten/rotting because of clogged pilot jets.. Then the weather/time takes it toll...

Oh well, it just makes em cheaper for blockheads like me.. ;)

GB :mrgreen:
 

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Sensei
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The stacked pilot and slow jets on the 450/500's are often not adequately cleaned or the inner one is often overlooked......Don't feel bad or alone.....I get lots at the shop that won't run right after the owner has cleaned the carbs himself.....A re-cleaning (properly done) is usually the fix..... I however, assumed you had followed Bill's proceedure, and was looking for some other cause for your problem.... Glad you got it sorted out..... :D Steve
 

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looks great! where did you find/ make/ aquire/ your body work? is it excessively loud?
 

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Discussion Starter · #15 ·
ihatespeed said:
looks great! where did you find/ make/ aquire/ your body work? is it excessively loud?
I make the body work. We have about 5 different tanks we offer and a couple seats. Soon to have a full faring and a couple more tanks. It is pretty loud. Very much like a track bike. Loud pipes save lives though.
 

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Discussion Starter · #16 ·
BAD NEWS!!!! Well, when trying to get a good idea of what jetting I needed I ran the bike to about 50 miles per hour and was about to hit the kill switch to check the plugs and she hot seized. Pulled the engine apart and #1 had a smeared piston and frozen rings. Anyone have a 74 mm piston and rings lying around? :D Back to the drawing board.
 
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