bought a cb360 but its in pieces need help with fuel/vacuum

[92civeg]

hi i recently just bought a 1975 honda cb360 but the carbs were off when i got it and there are no fuel lines or vacuum lines on the bike at all, i went to the local honda dealer and bought a clymer manual for the bike but there is no diagrams of there the lines go. If anyone could help with a diagram or just maybe a few goood pics of their carb area it would be greatly appriceated

thanks

[mydlyfkryzis]

No vacumm lines. An overflow gas line onthe bottom of the bowl, and the fuel line feed on the side.

Here's a diagram:

[92civeg]

cool thanks, i though the diaphrams were vacuum controlled?

this is my first bike with more than 1 carb and that uses diaphrams, does anyone have any idea of how to sycronize the carbs at least good enough to get it to run so i can begin tuning it?

engine pics would be great!

[mydlyfkryzis]

The diaphragms are controlled by the hole in the bottom of the round slide. As the air moves quicker past that hole, it creates the vacuum in the upper diaphragm chamber to cause the slide to rise. This way the velocity through the slide remains fairly constant, hence the constant velocity name. The constant velocity air atomizes the gasoline evenly. The gasoline comes out of the jet below the slide, in the throut of the carb. The needle valve rides up and down with the slide, contolling the amount of fuel coming up through the main jet.

[92civeg]

i found a link to dansmc.com giving a description of how to "balance" the carbs, it seems like its going to be no easy task.

there are definitely some parts missing, nothing major just a throttle cable starter button and both air boxes. and on top of the head there is a cover with a small pipe comming from it like a hose is supposed to go over it, anyone have any idea what this is?

i hate to sound like such a noob i have had many 2 stroke single carb bikes that ive rebuilt but this is a whole new beast for me

thanks again johnny

[mydlyfkryzis]

The adjustment itself isn't that hard. You need to remove the fuel tank to get at the screw and locknut that adjust the sync. It is harder to measure the difference. You need two vacuum gages and a way to connect the the vacuum port. The vacuum port is the screw on the rubber carb boot.

There is an adapter that screws into this. I used to have one but cannot find it now. If you are handy, a long screw, with a hole drilled lengthwise can make a nipple for this. You can do it by hand, but a drill press makes it easier.

Once you have the gauges and adapter, it becomes a little easier. I used to sync them every couple of months. The sync doesn't affect high end power that much, but has a big effect on the low end.

You can do a rough adjustment by using your hand near the exhaust. When in sync, the pulses are about even in sound and pressure. Not as good as a vacuum gauge, but you would be surprised.

If the sync is bad, the bike may even miss on one cylinder at an idle.

Good luck..

[92civeg]

ok here is the latest scoop on the bike.

this bike isnt mine yet its my buddys and he bought it a few weeks ago but doesnt have the time or money to put into the bike so hes just gonna sell it, i was planning on buying it but after a couple tests tonight im not sure that i want to.

I went to go check out the bike and first thing i did was a compression test
i pulled the plug out of cylinder #1 and poured a little oil in the cylinder, threaded the gauge in and began to kick it over first kick got about 90psi which i dont think is too bad but i tried to kick it again to see what it would max out at and the kick starter whould hardly move down. So i released all the pressure from the gauge and tried again, the kickstarter went down but it made no pressure and it didnt feel right, so i mover to #2 and it made about 125 psi but had the same trouble with the kickstart?

next i took the cover off the alternator and about 2-3 ounces of fresh oil came running out with it (maybe the oil i put into the cylinders?)this would indicate bad crank seals right?

then i took the exhaust pipes off to try to inspect the valves and one of them was wet in cylinder #1 couldnt tell if it was intake or exhaust though
(could this be a cause of the low compression number?

he bought the bike for 250 bucks and that is what he wants for it hes also throwing in a $25.00 clymer manual...let me know what you think

thanks-johnny

[mydlyfkryzis]

The oil is normal. It is a 4 cycle engine, so no crank seals. Oil always spills when you remove the alt. cover.

If the cluch is slipping, you will have trouble cranking it. Maybe you put too much oil in the cylinder and had a little hydrostatic lock.

The valves may need adjustment. A tight valve would leak a little and cause a compression loss. The wet may of been a little oil leaking by.

For the price, I'd give it a try. At worst, you could sell it as aprts on E-Bay and make what you paid on it.

[92civeg]

hmm so the oil in the alt cover is ok? i though it would it short out the alternator if the oil comes in contact with the alternator?

thanks soo much for your help mydlyfkryzis

[flynrider]

Did you have the throttle wide open for the compression check? If not, that could be the problem with the low number in the first cylinder.