cadillacjeff7777 Posted April 19, 2005 Report Share Posted April 19, 2005 I purchased this bike form my boss and he had had it for about 3 years, which it had sat the last 2 years. It ran on the right cylinder and not the left. Well, I put a compression testor in it and was running around 140psi on the right and 50psi on the left. I got the manual and reguaged all the valve clearances for both sides. I got the compression up to 140psi on both sides. Then I took off the carbs and sent them in. The service tech said that they were pretty nasty but cleanable. Then I put the carbs back on after they serviced them. I replaced the spark plugs and checked for spark...which it does have. I am assuming that the cam timing hasen't jumped because I get my valve clearances when I put each cylinder at TDC. Well, I have compression, fuel, and spark...and the left cylinder is still not running. I ran it at around 4-5K RPMs home from work and that was about a 30 min. drive. I was then able to get off the bike, and hold on to the header on the left side. Well, this gets wierder. if you put your finger in the left muffler, it is damp with fuel. If you ober the air filter box, remove the filter, and put your hand in and start restricting the air flow in causing to to draw MORE fuel, it will start firing off that cylinder. You can even remove the left plug wire and see no effect but if you leave it on and pull the right, it dies. i know that this is really off topic and a whole different species, but am hoping that someone out there may have some knowledge in this area too. 2008 DTS Link to comment Share on other sites More sharing options...
cadillacjeff7777 Posted April 19, 2005 Author Report Share Posted April 19, 2005 BTW....Bike only has 10,110 miles on it. 95 SLS has 327,000MI on it and runs flautlessly...go figure. lol 2008 DTS Link to comment Share on other sites More sharing options...
67coupedeville Posted April 19, 2005 Report Share Posted April 19, 2005 What I can tell from what you have told me is you have not syncronized the carbs. For 1980 I am thinking it should have round slide Micunie carbs but I can ask for sure at work tommorow. There are a couple ways to do this without a carb synker. Find a tiny drill bit and put the drill bit into the bottom of the slide at the air intake portion of the carb and make sure the slides are sitting at the same height at 0 throttle. To sync the carbs from 0 to WOT, put your index finger and pinkey finger into the air inlet inside the carbs and slowy open the throttle with your other hand so that the slides barely start to open. If the carbs are synked, both slides will open at the same time. If you feel tha one opens before the other one, they are not synked. If one slide opens before the other one, it will be letting more air into that cylinder and the engine will not be able to breathe correctly and you will lean out the that cylinder. To adjust the slides, there are two nuts on the top of the carbs, loosen the top nut and turn the bottom nut, you will be able to see inside the slides move up or down as you tune turn the bottom nut. Adjust it so tha they both open at the same rate and you should be synked. Just make sure the same gap is achieved when the slides are at 0 throttle and that they open at the same rate as you pull the throttle open. The other thing you should check is the choke cable sitting at the correct height when it is off. If the choke cable is not set correctly, one carb could be running at half choke all the time flooding that cylinder. To make sure the choke cable plunger is set correctly, you want to have a credit card's width of free play between the flipper switch and the mounting nut. What the carb synk tool does is measure the amount of air going into the carb, then you just adjust them to be the same. It will be more accurate with a sync tool but you can get it pretty close without. Hope this helps you out. Spence Link to comment Share on other sites More sharing options...
CadiKing Posted April 19, 2005 Report Share Posted April 19, 2005 67coupedeville, Will two mason jars with water in them hooked to engine vacuum work? I used to use four jars to sync (?) the carbs on my '75 Honda 400Four. That way you can visually align the amount of water drawn up the hose from the jars. Will that work? Link to comment Share on other sites More sharing options...
Cad1 Posted April 19, 2005 Report Share Posted April 19, 2005 What about a plugged fuel line on the left side? If you unscrew the bolt on the bottom of the carb does gas pour out of it? Also, pull the right plug wire off and try to make it run on the left without plugging the intake with your hand. You might have a jet that is still gunked up. Or your float level could be off. Carbs are pretty simple if you take your time and study it a bit. A manual might help. I wouldn't keep running it one one side. Cad1 92 Deville w/210k miles Link to comment Share on other sites More sharing options...
67coupedeville Posted April 20, 2005 Report Share Posted April 20, 2005 I've never heard about the Mason jar theory but from the sounds of it, it sure sounds like a feasible way to do it. And a plugged fuel line or could be the culprit as well. The best way to see if the fuel line is not obstructed is to pull the fuel line off the carb and hit the start button and see if fuel comes out of the gas line. There should be about 8 oz. of gas for 30 seconds of turning. That is also the way to check if the fuel pump is operating properly. Also an obstructed jet could be the problem. But if you did not sync the carbs to begin with, I would start there. Spence Link to comment Share on other sites More sharing options...
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