Mike's CB550 Project

[Bryanj]

I will let you off Ted, us old gits forget the odd thing, where am i posting?

[Mike_Berkshire]

Great tip on the cam chain tensioner; thanks Ted/Bryan. I haven’t seen anything that suggests I don’t need to take all the carbs etc off to check where the fuel leak is coming from though - wishful thinking! However, refitting the harness and getting to the cam chain adjuster will be easier without carbs and airbox in the way. Every cloud …………

[Laverda Dave]

You might know this already Mike, I used Kens method for adjusting the cam chain. Holding the kickstart  by hand so you are pushing against the compression, having released the tensioner lock nut. Having released the lock nut the chain tensioner will take up the slack, then just nip the lock nut in position. You can then tighten it up properly by using the screwdriver slot to hold the screw  and a spanner to tighten it up.

Pretty sure that's how I did mine iirc.

Can this method also be used for the 400/4 Bryan?

[Bryanj]

Works on all the Hondas as long as the mechanism is free but with 400 do it first or you singe your hands

[Mike_Berkshire]

So I now have the carbs off and have taken the opportunity to properly fit the harness and recheck the cam chain tensioner. That done I put the carbs in a baking tin on the bench and connected to a fuel source. After a few seconds fuel started leaking. The leak; more of a jet actually, came not from the brass tube in the bottom of the float bowl but from the spigot where the carb body joins the float bowl and it looks like the spigot acts for both carb #1 and #2

I have both bowls, floats, hinge pins and float valves off to clean/ inspect and check float heights for #1 and #2 and will rebuild and check again in the baking tin.

Is there any significance in where the leak is coming from?

[Bryanj]

What spigot? Do you mean the fuel inlet tee piece

[McCabe-Thiele (Ted)]

Is it the inter carb petrol pipe that is fitted with O rings that you are refering to??

[Mike_Berkshire]

Im away without a computer so I have cobbled together a picture the best I can. There are 2 spigots ringed in red. Hopefully this works.

[Mike_Berkshire]

Not my carbs just a picture I blagged on google

[Nurse Julie]

They have the vent tubes attached to them that vent to atmosphere down by the swing arm. The bowls are flooding, the fuel is going up and coming down the vent tubes, which it shouldn't. Sounds like a float valve isn't working.

[Bryanj]

If feul is comming out of there you have a float valve or two leaking fuel constantly into the float bowls, or possibly the O ring around the seat

[Mike_Berkshire]

Thanks all. When I get back to the bike next week I will carefully check float valves and seats.

[DomP]

Have fun Mike, my carbs (069a) are still giving me some grief, so much so that I've shelved it while I build my workshop.  Hopefully I'll have renewed enthusiasm over Christmas when I've got fed up of visitors. 

Keep at it though, you'll get there with the help of the forum!

[Mike_Berkshire]

Carbs stripped and I found a tiny piece of crud in the needle valve seat of number 2 carb. Removed reassembled and no flooding! Everything back together and the bike is running again . Still hangs once off the choke after a throttle blip. H slight stopped working too so I must have dislodged a wire or 2. Smells as if it’s running rich so next opportunity I get to work on the bike I’ll check the plugs to see if they’re sooty. Progress though.

[McCabe-Thiele (Ted)]

Since my 500 flooding fiasco I have fitted twin Aeroline filters in the forlorn hope of avoiding any repeat.