Topic: '71 CB500 ... it's ALIVE!

[dkruitz]

After rebuilding my carbs (first motorcycle) I reassembled the carbs back onto the carb stay, hooked up the linkages, the fuel lines, cleaned the tank and petcock.  And after a few cranks  - it's ALIVE!  WOOHOO!!

Did notice cylinders 1 & 2 didn't seem to be running though....  so after some fiddling, I moved the petcock to RESERVE and it seemed to put fuel in the carbs and it started running a whole bunch better.  I can currently get it to idle down to about 1200 before it sounds like it's struggling.  I don't have the airbox back on the front and that's probably going to affect things I know.

Some questions popped up from last nights happy events:
1.  If I shift into first with the clutch fully depressed, should the wheel move?  I think the clutch needs adjustment.
2.  The fuel line I bought seems to be too fat (thick walled) to fit through the carb stay fuel line holes and line up with the fuel T.  I spotted some thin walled 1/4" fuel tubing for small engines at Tractor Supply (plus it's semi clear) will this be OK?
3.  Do I have fuel lines running correctly?  The petcock has two fuel barbs, I have one running to carbs 1&2, and the other to carbs 3&4.  OR, are the barbs set up one each for Run and for Reserve -- is that why carbs 1&2 didn't seem to get fuel at first?

Thanks for the help and encouragement so far on this great board!

P.S. I can even kick start it - well at least when it's warm... 

[dusterdude]

congrats,the fuel lines are run correctly,as far as the fat hoses,thats typical as far as auto parts stores hoses go.

[TwoTired]

RE:
#1. Assume the rear wheel turns when on the center stand.  Normal.  Oil between the clutch plates causes some viscous coupling.  You should be able to stop the wheel easily.
Otherwise, you have a dragging clutch needing adjustment or other attention.

#2.  The fuel line nipples are designed for 5 or 5.5 mm I.D. hoses.  This is close to 7/32 inch size, but the local auto Farts will sell you vacuum hose in this size, which gasoline dissolves.  The metric sizes can usually be found at the Honda parts counter.  1/4 inch I.D.hose is too big and will require hose clamps to cinch it down securely.

#3.  The two outlets on the petcock are fed from a log.  Low fuel levels on main setting will only trickle feed the first outlet from the log due to low head pressure.  Reserve setting changes the head pressure so both the log outlets get fuel.

This arrangement is quite handy while driving as the engine doesn't quit completely when the fuel tank gets low.  There is a slight loss of power/speed.  Shortly after one eyebrow gets raised, you reach down and flip to reserve.  Shortly after that the power and speed return along with a shallow grin.


Cheers,

[dkruitz]

Thanks guys.  Can you think of any reason not to try the thinner semi-clear fuel line designed for small engines?

[dustyc]

The engine heat may cause it to collapse?  I really don't know of any reason as long as the inner diameter is the same as what is supposed to be there.  Try it and see. 

I hate to plug places, but CRC has tinted fuel line that is for motorcycles.