Author Topic: 71 CB450K4 float levels  (Read 215 times)

Offline r1_pete

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71 CB450K4 float levels
« on: February 09, 2020, 06:24:12 PM »
I have my 450 running, which is surprising as it was seized when I got it, but not very well.
New plugs, points, condensers, nice bright blue spark at the right time.
Carbs are spotless, all primaries etc cleaned out, and rebuild kits inc floats.
The bike is difficult to start, will run nicely at highish revs, but as it settles to tickover it dies, seems to need air which leaves me thinking its float heights.....

Can someone confirm is it 20mm to the gasket face or to the body flange?? I have them set to gasket face, which seemed the most common advice, but looking at the card tools they must set it to body flange, which is a 2mm difference.....
2009 Yamaha XJR1300 sold
1977 CB750F2 café racer project. Sold
1972 CB750K2 hot rod. Sold
and an E-Type Jaguar that considers itself worthy of all my spare cash. Sold

1971 CB450
1978 Reliant Scimitar Cosworth.

Offline MrDavo

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Re: 71 CB450K4 float levels
« Reply #1 on: February 25, 2020, 07:24:49 PM »
I used the card tool, and set the level using the card tool against the carb body. I took the carbs off and held them vertically, a pain but otherwise it just wasn’t working for me when I tried to do it with the carbs in situ.

There seemed to be a fine line between too much fuel and not enough when I was trying to do it by trial and error, using the tool properly made a huge difference as it cured similar problems to yours. Tickover is now reliable, previously it had been all over the place.
1969 Honda CL450 'Scrambler'
2005 Harley XL1200R Sportster


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