Problem with the Carbuerator adjustments????

[ABarnby]

My bike is a 1984 venture. I purchased it last year and rode it through the summer months. It has 31,000 miles and is in very good condition.

With choke it started and ran pretty good, and after it warmed up ran good. It actually seamed as the more I rode it the better it ran. I went to take it out last fall and started hard an would not idle. I sea foamed it and let it sit for a few days and the result was not any better. I left it for a winter project and now it is the middle of March, so it has turned into a spring project.

I decided to start with a carb cleaning and as I was disassembling I found the 2 Left Carbuerators lifted out of the intake boots extremely easy. I found the problem. Pressed the carbs into the intake boots until they popped in and tightened the clamps. Gave each side a tug and the reassembled the air box. Then started and it ran much better but not as good as it had in the past. Pulled the plugs and founded them to be black, cleaned them up with some fine sand paper and a fine wire brush, hit them with carb cleaner and compressed air.

Somhere is where I am at, it starts and runs on choke. Am able to increase the rpm by giving it quick short bursts of throttle. After it warms up it will idle off choke, the throttle is responsive, however the idle fluctuates. Give the throttle a quick snap up to increase the rpm and release the idle will drop down to 400 or 500, stumble and stall. I can keep it running if I give it some throttle though. Also when idling at 900 or 1000 rpm and warmed up the idle will creap up to 2000 RPM. If I rev it up the idle will drop back down to the 400-500 range, stumble and stall if I don't give it any throttle. The throttle response is good when it is warmed up though.........

i don't think the carbs need a cleaning but just adjustment.

Thoughts..........

[BlueSky]

Maybe the so called shotgun cleaning?

[cowpuc]

Hi Barn.. Thinking I never got to "cyber" shake your paw and welcome you to VR so - put er there and to VR!!

 

About your bike.. May sound crazy (you will probably have no problem finding folks on here to say that so I just beat em to it) but I have personally never any decent luck with cleaning the peanut plugs in these scoots. Just has never worked for me. Would advise to shoot down to Auto Zone, buy new - check the gaps and stick em in. In the future, cold start with choke if needed but work it off choke as quickly as possible cause, once again, these little "D" peanut plugs do NOT take to kindly to blackening.

 

If it runs good and has good throttle response after warming up it is very possible you are just experiencing cold bloodedness.. Personally I would do a good tune up, starting with pulling the slides, checking the diaphrams for pin holes, checking the slides for ease of movement in the carb bodies, make sure I have a clean air filter and the cover is intact. Drop in some new plugs, maybe even spend the big bucks on new plug caps or at least ohm out the old caps to make sure they are not failing.. Stick er back together, with the choke off I would hit the starter and see what happens.. If it starts and idles with no choke I would proceed, if not I would give her some choke and start it and let it warm up to not needing choke while I spit check each header to see if its hittin on all four (these things run deceptively well on three). After being satisfied she's hitting on all four and she come up to temp of not needing choke I would shut er down and hook up the gauges to check carb sync.. Start it, sync it and see how she idles and how she responds to throttle. Should set your idle at a grand and have good sync there BUT I always like to also spot check my gauges at around 3k cause I spend a fair amount of time in the range.

Put if back together, ride it, make sure temp is fully up, check crispness of response on throttle.. If it's wandering in RPM range, slow to return to idle after all that. Check throttle cables for proper slack (should have small amount of looseness at throttle twist when idling) and for stickiness.. Lube cables.

Lean conditions from vacuum leaks can cause strange idling conditions too. Some folks spray carb cleaner of even starting fluids around vac hose connections and intakes. I like using my propane torch (unlit) to locate and starting fluid to pin point leaks.

 

Hope this helps somehow

Puc

[ABarnby]

Thank you for the replies.

So to update:

Today I messed around with the carb sync, it was way out. I do not have a sync tool so First I tried with a single gauge and a clamp to dampen the needle bounce. As expected it turned out to be frustrating. So of to the auto parts store I went and picked up some clear tubing and tranny fluid and made my own. Started with carb 1 and 2, using a clamp to prevent the tranny fluid from getting sucked right in. Got those set and then did 3 and 4 and then 2and 4. She now runs pretty good. Checked the air/ fuel screws and all 4 where about 2 1/2 turns out.

So now the idle is about 1000 rpm and searches about 100 to 200 rpm.

I took the temp of the exhaust right at the head, cylinder 1 was about 420 and cylinder 2,3,4 where all about the 300 range, not sure what to make of that?? 1 lean and or the others rich? planning on pulling the plugs and changing them tomorrow or at least take a look at them and see what they look like

Any suggestions for that temp range?

[WildBill1]

Pm Lug Nut he got his problem or carb fixed.

[BlueSky]

Synchronizing the carbs when the bike isn't running right might do more harm than good or it seems to me anyway. After you get it all sorted out, sync it again.

[mraf]

Spark plugs are about the cheapest fix . I change mine every year just for piece of mind and good fuel mileage. I had a 83 that was notiorious for fouling the plugs. But ran like a raped ape. Throw new plugs into it and then check the temps. Sounds like your pretty adapt at wrenching and will wring it out eventually.

[garyS-NJ]

Check your plug wire too. But hunting around is often an air leak on throttle shafts or choke circuit.

[ABarnby]

As it stands right now it looks like a 24 hour soak of sea foam in the carbs did the trick. I filled the carb bowls with sea foam, tried to start it a couple of times and let it sit. Tonight I drained the bowls, let them fill with fuel, then tried starting it a few times. When it did start it was pretty rough. After a few times of that it stared and ran. I let it run for a while and kept giving the throttle quick snaps. Then to my surprise the popping stopped, idle smoothed out.

 

It it has smooth idle, a snappy response on throttle, and doesn't stall after throttle release. Will see what happens tomorrow. Going to sync the carbs again and change the plugs, or atleast give them a look.

 

There is a great deal of information on this forum. It sure is beneficial to take the time to search and read some of the threads. Also thanks for the replies guys. It's always good to hear ideas on where to start.