There's no vacuume attachment on my carb manifold!

[THE ROLLING BONES]

All the videos I have seen on carburetors all have a vacuum on the intake manifold and mine doesn't! I have a 1977 xs650 and an owners manual but it doesn't show where all the fuel lines go! When I got the bike all the lines and the carb were of the motor! Could someone explain to where and what lines I need and where they go starting from the petcock! thanks! If you could tell me what wires are needed just to get the bike started, that would help also! I just want to start the bike not ride. Picture the motor of the frame! Just using the kick start. I adjusted my cam chain,valves and timing. I set the valves to the specs that were in the manual(intake .05mm-exhaust .15mm ) Should I keep it to spec or change the gap since the bike is 36 years old! I gaped the left side intake first then checked the timing and then the gap (adjusted)checked the timing again and checked the gap and BADABING! then moved to the left exhaust and then the same thing on the right! Timing is set! Now I want to set the carbs So any help on how to wire for a quick start nothing to fancy with onlt the kick start would be great!

 

[wallywheels]

Do you still have a battery or are you going capacitor? Do you have a Pamco ignition or stock if so is it points or electronic? Are you running single Regulator/Rectifier or stock separate ones? single coil or double? Just give a run down of what systems your working with It will help with the explanation of simplest wiring to run bike.

 

[wallywheels]

First one is with charging second is without from what you PMed me this should be what you are working with. If you have a well charged battery and want to start it without the charging system it is very simple but I recommend charging system for any running of a period of time. Also forgot to edit out the second fuse in the non charging diagram is not necessary. If anyone sees any issues please chime in as for the carbs I would need a photo to see what you have done so far.

 

[XSLeo]

In both diagrams the fuse feeding the ignition should be a 7.5 or 10 amp fuse. But either will work. The second, being just the ignition is more like you want.
I'm not sure if they used vacumm petcocks in 77. I think they were just plain petcocks. There is a fitting that points back from each petcock. Run a hose from there into the fuel line inputs on the carb. These inputs are beteen the carbs. Just above thew float bowls. One in each carb with a crossover between the carbs.
If there is a second small fitting pointing inward on the petcocks, then they are for vacumm. They would go to the fitting on the carb holders. If no fitting in the carb holders then no need for fittings in the petcocks.
www.amckayltd.com/carbguide.pdf is a good read.
Leo

 

[THE ROLLING BONES]

Thanks a lot guys! Wally I did try both methods! I don't have any pipes on the motor and hope this doesn't matter! The motor Turns over and I did see some flames! And some gas shooting out out the air intake part of the carb! I don't have any air filters on at this time! Sounds like she want to start but doesn't! I rechecked the timing and the gaps on the valves and they are good! I might be having carb issues! The plus are getting spark and noticed they were a bit wet!

 

[wallywheels]

you may have possibly switched the wires feeding the coils from the contact breakers try switching them and see what happens

 

[THE ROLLING BONES]

Will do! Been going nuts! New gas,sparkplugs till I realized the old ones were still good,timing twice today! Hope switching the wires work! Thanks!

 

[5twins]

Stock '77 carb manifolds had no vacuum ports because the stock '77 petcocks were not the vacuum type, they were the normal old fashioned manual kind. The 1st vacuum petcocks came along in '78.

 

[THE ROLLING BONES]

BOOOOOOOM BABBBBYYYYYYYYYY!!!!!! Got her going! I reversed the points wires and then adjusted the valves! I used a spark plug gapper to adjust the valves yesterday,that little round one! So I went out and bought feeler gages and boy what a difference! Thanks a mill!

 

[oldbiker]

BOOOOOOOM BABBBBYYYYYYYYYY!!!!!! Got her going! I reversed the points wires and then adjusted the valves! I used a spark plug gapper to adjust the valves yesterday,that little round one! So I went out and bought feeler gages and boy what a difference! Thanks a mill!

............................. hi guys i,ve got a 1976 special frame,,,,,,,,,then i,ve got a 1983 xs650 with 1st over pistons etc....... and i,ve got cv38,s carby which have been on there for 12 years and the inlet manifolds do not have vac......... inlets at all its never worried me or mt yam regards oldbiker

 

[THE ROLLING BONES]

Hi ya oldbiker! How would you sync your carbs without any vac inlets? Just wondering!

 

[weekendrider]

Your carbs have plugs that are replaced with spigots for the purpose of syncing.

 

[5twins]

Your '76-'77 carb set should have vacuum ports on the carb bodies just below the mix screws, blocked off by a large flat head screw. Installing threaded nipples there will allow you to connect sync gauges of some sort .....

 

[XSLeo]

On the points bikes you use the dead cylinder method of carb setting. You set both the idle speed and carb sync with that method. You can use it on the TCI bikes but need a better way of "killing" one cylinder.
I made up a set of tools for this. I found a nail the same size as the threaded end on a spark plug, threaded it to match. I then made an aluminum tube threaded to match. I thread one of the nails into the tube and thread this on the plug. One tool on each plug.
I then use a jumper wire with alligator clips at both ends. When I want to "kill" one cylinder I hook a clip on a fin on the engine, then hook the other to the tool between the plug and wire. This grounds the plug wire, "killing" one cylinder. Just hook to ground first.
Adjust as in the dead cylinder method. Unhook the jumper and do the other cylinder.
The dead cylinder method is described on page 20 in the Clymer book, Page 77 in the Haynes.
Leo

 

[THE ROLLING BONES]

Oh I see! Thanks! So what are the smooth looking inlets above the fuel inlets on my carb? Trying to get a pic but hard to get the camera in there! Try to post it!

 

[THE ROLLING BONES]

Heres a pic of my carb! If you look above the right side fuel line you'll see a smooth brass inlet! What's it for?

 

[5twins]

Those are your float chamber vents. They don't get connected together and simply vent to atmosphere. They originally had short clear hoses on them that just hung down between the carbs. You can add new hoses or just run with nothing on them .....

 

[THE ROLLING BONES]

Perfect! Thanks a mil! I swapped the carb needle for a shorter one yesterday. How will this effect the carb? Should I use the original size? I will be going with air pods with a custom air intake pipe running from the front of the bike to the air fillters for more air! and staright pipes! Let me know if thats a bad idea! thanks

 

[5twins]

That will make it run richer, probably too rich. Usually, you simply adjust the height of the needle that's in there and that's enough. Read the carb guide in the tech section. You obviously have very little carb knowledge, at least as far as these 650s go, and you're not going to have much tuning success until you learn more about these carbs.

 

[THE ROLLING BONES]

I have very little knowledge your right! Getting buy though! Have been reading and am finding great info!. It's just that when I got the bike it was all in pieces! Basically in boxes! The carb was off the motor and so on! So i hope you can bare with my questions! Thanks!