I have a 1979 Suzuki GS750 and it fires great on 3 of the 4 cylinders, but not the 4th.

SOURCE: 1979 suski 750,bike runs on 2 left side cylinders,

Hi and welcome to FixYa,

With the indulgence of craigjamesbt...

A few additional ideas to consider:

• it would be an electrical/ignition issue if 1 & 4 or 2 & 3 will not fire but not 3 & 4;
• almost always, raw fuel on exhaust indicates a flooded engine. A flooded engine would most likely be a carb issue;
• best way to determine if it is an engine concern is to do a compression test;
• a way to test the right carb pair is to deliberately starve them of fuel by temporarily plugging/blocking the inlet port/seat with rubber similar in appearance as to those used for glue gun, not installing the needle and float. Assemble the carb and install. Start the bike and use/spray carb cleaner on the right side carb. Note if 3 & 4 will fire even intermittently.

Daniel Dollive

• 315 Answers
• Posted on Aug 30, 2009

SOURCE: I have a 1990 katana 600 ,only running on 3/4

sounds like theirs no fuel goin into the mixture at the cylanders, best bet is to have the carbs tuned, they have to be tuned in series or it will throw the others off. so it;s best to have that donme at a shop unless you have a carb tuning kit then by all means go for it If your bike has been sittign a while then you probably have varnished carbs, this is easily fixed by getting a fuel addative like gunk
http://www.gunk.com/msds/M2616.PDF

http://www.gunk.com/fueltreatments.asp

also note that you are running a mixture with a motorcycle engine so not as mucth addative needed can get instructions on how mucth to add probably a cap full or two to a gallon of gass will be close to the limit you need. but it will clean the varnish out also has to run it a bit to get the fuel to flwo threw the system and eat the varnish andf deposits. good luck.

Testimonial: "carbs are *MINT*"

SOURCE: My 1981 Suzuki GS1000G has no spark on 3 of the 4 cylinders

cdi unit get the manufacturers to test the cdi out and get back to me

SOURCE: My suzuki intruder is missing backfiring on the

Did you sync the two carbs? If not the rear may be getting all the gas from the rear carb and none to the front. Twist throttle engine off and see if front carb cable is pulling the carb open.
Also unscrew the spark plug boot from the front spark plug wire and trim 1/8th inch off the wire and screw the boot back in. The plug wire end may be corroded on that wire.

SOURCE: My 98 Suzuki VL1500 has a weak spark to the rear

check your carbs. it might be dumping to much gas in that cylinder, causing the plug to fowl out and have a weak spark. make sure the carbs are adjusted and then sync them for proper fuel air mixture.