fouled plugs & elct. ?

[Anonymous]

The carbs on my 79 GS750L were rebuilt last summer but now the plugs will turn black after a 20 mile ride or less and the bike will not start the next day until I pull the plugs and clean them my ? is were do I need to set the fuel screws & what are the screws in the bottom of the carbs by the bowls for and how do they need to be set. My other ? is my headlight keeps blowing the low beam side of my light high side works fine any thoughts? Any help would be great
I got the bike last summer from a guy that had it sitting in his shop it has a little over 6000 miles on it lookes like someone layed it over & parked it not to bad of road rash though my husband said he would repaint it for me after I got it going better.

[earlfor]

Re: fouled plugs & elct. ?

If the carbs were rebuilt last summer and the bike ran fine, then I doubt the problem is your fuel pilot and air pilot settings. If the bowls and jets had gummed up, the bike would have a fuel starvation problem and not a rich running problem. Your headlight is blowing out the low beam and that is an electrical problem. I suspect the black and sooty plugs is also an electrical problem. I would check the wiring harness connectors and particularly the electrical socket on the rear of the headlight for corrosion.
Do you still have the points ignition system. If so, it probably needs new points and the ignition timing and gaps reset. Also, check your ground wires to make sure you have good, clean connections. Check your battery voltage too. If the bike has been sitting and the battery has not been kept up with a trickle charger and allowed to self drain, its very likely you need a new battery. Everything on the bike runs off the battery. The charging system only replaces what is used from the battery. A battery not capable of holding a good charge means the bike cannot run properly.

Earl

The carbs on my 79 GS750L were rebuilt last summer but now the plugs will turn black after a 20 mile ride or less and the bike will not start the next day until I pull the plugs and clean them my ? is were do I need to set the fuel screws & what are the screws in the bottom of the carbs by the bowls for and how do they need to be set. My other ? is my headlight keeps blowing the low beam side of my light high side works fine any thoughts? Any help would be great
I got the bike last summer from a guy that had it sitting in his shop it has a little over 6000 miles on it lookes like someone layed it over & parked it not to bad of road rash though my husband said he would repaint it for me after I got it going better.

[Anonymous]

Re: fouled plugs & elct. ?

The carbs on my 79 GS750L were rebuilt last summer but now the plugs will turn black after a 20 mile ride or less and the bike will not start the next day until I pull the plugs and clean them my ? is were do I need to set the fuel screws & what are the screws in the bottom of the carbs by the bowls for and how do they need to be set. My other ? is my headlight keeps blowing the low beam side of my light high side works fine any thoughts? Any help would be great
I got the bike last summer from a guy that had it sitting in his shop it has a little over 6000 miles on it lookes like someone layed it over & parked it not to bad of road rash though my husband said he would repaint it for me after I got it going better.

Screws on the bottom of the bowls are drains.

One quick check for the black plugs/running rich is the air filter. If it hasn't been cleaned in years then it's high time. A maintenance manual will tell you how. You should really have one. Get Clymer, Haynes or the Suzuki factory manual.

Michael

[Anonymous]

Sorry forgot to say I have a new K&N air filter & plugs were giving me the same trouble last summer I just did not ride it very much do to the fact I did not have my bike DL yet. The screw that I was asking about was not the drain screw this one is located in the bottom middle of the bowl eng side. The guy that rebuilt the carbs for me was not sure what it was. He also looked at the points and said they looked fine (I orderd a tune up kit today) so did not do anything to them at the time.

[Billy Ricks]

If the guy didn't know what the screw did he shouldn't have been working on the carbs. That's the low speed fuel jet. The one on the side of the carbs is the air jet. Lightly seat the fuel jet then back it out about 2 turns and go from there checking the plug color. The float level could also be set wrong.

[Anonymous]

hey thinks I'll do that in the a.m. what should the air screw be set at (a good place to start anyway) I really want to get this bike going Gas just hit $1.999 here the good stuff is 2.20 I think. The guy that built my carbs had a 1980 gs 750 but he said the carbs were diffrent (but maby he was full of it) thats why he did not know for sure. any way thanks for the help.

[mcconnell]

GS, did your problem with the plugs fouling start as soon as the K&N went on? I had exactly your problem the first time I put my K&N on. I had over-oiled it, decreasing the airflow through it so much the fuel mixture went way too rich. As soon as I recleaned it and LIGHTLY oiled it, everything was fine. Good luck.

[Billy Ricks]

He was right about them being different. He has CV type carbs that only have one adjustable screw for idle mixture. Everything I've read says to set the air screw at about 2 1/2 turns out if I remember right. Check for a thread in this section titled Carby Jet Sizes. On the second page of that thread you'll find a post by Earl Formes that gives some starting points for each of the screws. Also, if the bowls are filling too much you can run rich. Lightly seat those screws. Don't crank them down.

[Anonymous]

thank's i'll look for that thread. about the air filter reply I do not know it was put on before the bike was ever started (did not have one when I bought it) so I can not compare but I will to clean it and reoil it lightly. I want to think everyone for there help this is a great forum I am glade I was told about it.

[earlfor]

Angel, I have a 79 750. The screw underneath the float bowl at the front is the fuel pilot screw. Set it to 1 1/4 turns out. The screw on the side at about the middle of the carb is the airscrew, set it to 1 3/4 turns out. A caution when you screw the screws all the way in to begin counting turns out. Us a VERY light two fingered touch, it is too easy to break off the fine point and wedge it in the carb passageway if you are heavy handed. Think lightly. I set float bowl heights to 25 mm. Holler if you need a description of how to set float bowl heights.

Earl

thank's i'll look for that thread. about the air filter reply I do not know it was put on before the bike was ever started (did not have one when I bought it) so I can not compare but I will to clean it and reoil it lightly. I want to think everyone for there help this is a great forum I am glade I was told about it.

[Anonymous]

I worked on my bike today checked everything you all suggested reset fuel & air screws took bike out on a 16 mile ride plugs looked just like they should (not black )I can not wait for sun. (it's starting to rain now) so I can take it on a longer ride. Thanks for everyones help this is truely a great forum. I am happy to know that there is people out there that are willing to help out someone that they do not know THANK YOU.

[Anonymous]

Hey Earl can you give me a rundown on how to set the float height. I believe that may be causing some of my issues on my 77GS750.
TIA

Michael