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Floods after valve adjustment

  • Thread starter Thread starter Hoggystyle
  • Start date Start date
H

Hoggystyle

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i picked up a 1979 GS550E as a winter project and have been working out the kinks and doing routine maintenance. i got around to the valves a few weeks ago, the clearences were non existent. i had to go up 2 sizes, and 3 on a few to get it within spec. Original head gasket, 27,xxx miles, so the PO never checked the valves. it came with a Yoshimura 4-1 already installed and jetted, but no air filter. before the valve adjust it ran fine, maybe a tad rich without the filter. after i adjusted the valves though, i couldnt get past 3K RPM with bogging down. I pulled the Carbs again, and adjusted the floats. the question i have is how to dial in the carbs. The Jets are 92.5 Mains, 50 starter and 15 Pilot. the mains were screwed in really tight so i dont know whether to follow my Clymer manual and turn out the mains 2 turn from lightly seated and the specs for the rest the same way, or if there is a different procedure with the 4-1. it has the factory airbox with a Unifilter foam filter element, and new intake o-rings, as well as Carb orings from Cycleorings.com. let me know what you thing, thank you
 
You seem to be mixing terms, or be confused about what you need to do:

1. You don't loosen main jets, They should be snugged down
2. You do turn the air screw and the fuel screw - this 79 does have VM Carbs, right?
3. What is a starter?

Also, I'm assuming you cleaned the carbs per the tutorial?
 
sorry about that, this is my first street bike and my first real experience with carburetors so im a little foggy here. it does have VM carbs. i dont get your 3rd question. it has a Dyna-s ignition if thats what you mean. i didnt dip the carbs but i did spray them out well

Edit: oh i see what you mean, im definately mixing up my terminology here. the jet i was referring to is the one that caps off the pilot jet i think.
 
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Hoggystyle said:
i picked up a 1979 GS550E as a winter project and have been working out the kinks and doing routine maintenance.

it came with a Yoshimura 4-1 already installed and jetted, <SNIP> but no air filter.maybe a tad rich without the filter.

after i adjusted the valves though, the mains were screwed in really tight so i dont know whether to follow my Clymer manual and turn out the mains 2 turn from lightly seated
Click to expand...
Well lets see, you bought it and found it had no maintenance done to it, it came with no air filter installed yet still ran a tad rich, then you installed the air filter which made it run even richer still. plus, someone installed a 4 to 1 that was supposedly 'jetted for the pipe' and who knows if that was even done correctly.

my best guess, your jetting is too rich and I'd question if even the needle height is set correctly.

I would suggest you do a bit of searching to see what other people have came up with for settings after having done similar modifications.
 
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Start at the beginning, do the complete carb cleaning process as described in Basscliff's welcome, learn the terminology, learn what all of the different jets and screws do. Then find out what size jets your bike had originally and make changes to the jet sizes that are appropriate for you pipe and air intake system. With 92.5 main jets it was NOT jetted correctly for a 4-1 pipe. Haphazzard poking around with things you don't understand will never make a bike run correctly.

There is guaranteed to be a lot of other maintenance that has been neglected thirty years, it all needs to be done.
 
Hoggystyle said:
sorry about that, this is my first street bike and my first real experience with carburetors so im a little foggy here. it does have VM carbs. i dont get your 3rd question. it has a Dyna-s ignition if thats what you mean. i didnt dip the carbs but i did spray them out well

Edit: oh i see what you mean, im definately mixing up my terminology here. the jet i was referring to is the one that caps off the pilot jet i think.
Click to expand...

I still have no idea what you're talking about. The VM carbs have main jets, pilot jets, air screws and fuel screws for adjustments. The fuel screws are under the front of the carb and have a cap over them



VMcarb-1.gif
 
ok, so i read the tutorial and started to get familiar with the parts and names of everything so hopefully i dont sound like a complete idiot haha. so what i have is: Main - 92.5 Bleeder 50 Pilot 15, and the needle on the 3rd clip from the bottom. i know that stock for my bike is Main 80 Bleeder 40 pilot 15 . is there a general rule of thumb with 4-1 headers and how many sizes you increase the jets by? i am leaving the lid on the airbox and using a regular filter so the only change would be the header. thanks for your help, and sorry for the confusion:o
 
im pretty sure. i have cross referenced a few different sites and that seems to be the right size. i also checked keyster rebuild kits and they are also 80.
 
I am not going to be much help with the carburetion issues, but I was intrigued by this statement:
Hoggystyle said:
i got around to the valves a few weeks ago, the clearences were non existent. i had to go up 2 sizes, and 3 on a few to get it within spec.
Click to expand...
Are you saying that all your valves were LOOSE? :confused:

Usually, the valves on these bikes tighten up, and you have to go 2 or three sizes DOWN on the shims. :-k

.
 
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Hoggystyle said:
ok, so i read the tutorial and started to get familiar with the parts and names of everything so hopefully i dont sound like a complete idiot haha. so what i have is: Main - 92.5 Bleeder 50 Pilot 15, and the needle on the 3rd clip from the bottom. i know that stock for my bike is Main 80 Bleeder 40 pilot 15 . is there a general rule of thumb with 4-1 headers and how many sizes you increase the jets by? i am leaving the lid on the airbox and using a regular filter so the only change would be the header. thanks for your help, and sorry for the confusion:o
Click to expand...

Okay, so back to your original question - what's the right carb set up?

It's hard to say because every pipe/air filter combination is a bit different. So, I'd start with

Main 92.5
Pilot - 15
Air - 2 turns
Fuel - 1 turn
Needle - 2nd clip from the bottom

Then, do some plug chops and see what you have going on

The not revving issues generally points to air leaks, but could possibly be overly rich. Your plugs don't lie, get out your plug wrench
 
"Usually, the valves on these bikes tighten up, and you have to go 2 or three sizes DOWN on the shims."

OOPS! i meant down, i making all kinds of mistakes today!

well before the valve adjustment i could rev to the redline with no staggering, and i sealed my airbox and installed new intake o-rings and the boots don't have any cracks and are still fairly flexible. before i pulled the carbs yesterday, i would rev and then a few seconds after returning to idle, the left carb would pour gas from the overflow tube. for a few seconds, but only when on the sidestand. my floats are also quite a bit off so that could be part of the problem, i tested the float valves and they werent sticking. i didnt have this problem before though.
can i do accurate plug chops without riding? its snowing pretty heavily here and will be for a few weeks so i cant take it anywhere anytime soon.
 
No, but you can clean your carbs properly and put in new O rings

Plugs chops under load only

If you can get a Colortune, that would get you close
 
i have one soaking as we speak in carb dip and i just ordered a new set of o-rings for the carbs since i fouled a few up taking them off to clean. i saw a carburetor sync kit at Harbor Freight, so ill see if i can pick it up next time im in that area. one thing that scares me is that the bike smokes. its all white and smells strongly like gas, not oil. could an overly rich condition cause this somehow? i know when i cleaned the carbs the first time it stopped for the most part
 
If the HF set is a set of vacuum gauges ?? Don't buy them. If it has the stock air box & filter Just the pipe IT is too rich from 80 maybe go to 87.5 . Get them cleaned, air box sealed good filter Adjusted as sugested. then see what the plugs say.
Also make sure you have 12 volts at the coil...
 
i hear you on the harbor freight thing, usually they have a bout 90 percent junk stocked at all times, but for small things you dont use much it can be a good resource. ill try the smaller jets. Big T suggested the 2nd clip up on the needle, does that sound about right as well?
 
Hoggystyle said:
i have one soaking as we speak in carb dip and i just ordered a new set of o-rings for the carbs since i fouled a few up taking them off to clean. i saw a carburetor sync kit at Harbor Freight, so ill see if i can pick it up next time im in that area. one thing that scares me is that the bike smokes. its all white and smells strongly like gas, not oil. could an overly rich condition cause this somehow? i know when i cleaned the carbs the first time it stopped for the most part
Click to expand...

Is your oil overfilled?

Like with gas?
 
it was even before i did the valves. i changed the oil and filter and it reeked. i think some found its way back in though bc my floats were all out of whack. i do think i overfilled with oil though. the bike came with an aftermarket oil cooler so i was trying to compensate for that and dumped too much in
 
ok so i got the carbs dipped and sprayed out with carb cleaner. i ordered some 87.5 mains from jetsRus, now i just need to figure out the needle clip postion. ive heard that usually you only need to raise the clip one notch, but i dont know where the starting point is. with stock carburetors, in your experience, where is the needle usually?
 
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