Motorcycle Forum banner

21 - 32 of 32 Posts

·
Registered
Joined
·
26 Posts
Discussion Starter #21
I think all the plugs were similarly black, but ill have to check that again.

How would the fuel get into the oil? I guess if fuel got into the oil that would make the oil level too high. And the fuel would thin out the oil right?

The little plungers attached to the floats seemed alright, but those cant cost that much i might as well replace them. I read the manual but I am still a littl confused on how to check/adjust float height. Ill go read it again. Are the needles adjustable or would I jsut need to replace them. I didnt see any damge to the needles themselves or the plunger rubber.

The petcock does not have an off setting, its a vacume system.
 

·
Super Moderator
Joined
·
12,597 Posts
How would the fuel get into the oil? I guess if fuel got into the oil that would make the oil level too high. And the fuel would thin out the oil right?

I read the manual but I am still a littl confused on how to check/adjust float height. Ill go read it again.

The petcock does not have an off setting, its a vacume system.
Fuel gets into the oil by: Carb overflows and raw gas is sucked into piston. It runs past rings into crankcase. Yes, it thins the oil !!!

Float adjustment is often done by bending a tab on the float mounting arm and the measurement is usually made with the carb OFF the engine and upside down.

OK, here's one more idea for locating which carb is causing the problem.
Do the carbs have overflow tubes (a little nipple sticking down from the float bowl) ? Consult the manual to see for sure.

If so, figure out how you can hold it up straight for a while (center stand, wheel jack or a buddy). Remove hoses from overflows (if there are any) so you can SEE the individual nipples on each carb. Put petcock on PRIme and watch the bottom of the carbs. The one(s) in trouble should start leaking gas out of the overflow after a minute or so. Have something under the carbs to catch the gas. Put back to ON to stop the flow.
NOTE: Bike should ***NOT*** be running when you do this!


Remember that this may be an actual float failure. Brass floats sometimes develop leaks and sink instead of floating. Other types of floats can lose boyancy too.

At some point, you're gonna want to check that petcock to be sure the vacuum shut-off is working........but you may find that out while doing the above.
 

·
Registered
Joined
·
26 Posts
Discussion Starter #23
I couldnt find overflow tubes on the carburetors. There are drain valves but thats a screw.
I found out that the hoses that attach to the engine under the exhaust pipes is the PAIR system. This is the air supply. I wonder if the PAIR valve could be malfunctioning? This is right above the engine too, when it heats up some could this mess up something?

I can scan a few pages from my manual if you would need to check that out. I think i understand from the manual how to adjsut the floats.

The floats are plastic by the way. I can take them out and submerge them to see if they take on fluid.
I guess I have to take the carburetors off again... Ill do that tomorrow morening after i get off work.
 

·
Super Moderator
Joined
·
12,597 Posts
I couldnt find overflow tubes on the carburetors. There are drain valves but thats a screw.

I wonder if the PAIR valve could be malfunctioning? This is right above the engine too, when it heats up some could this mess up something?

I guess I have to take the carburetors off again... Ill do that tomorrow morening after i get off work.
On my Zuki, the drain tube and the overflow tube are one in the same (the one tube serves both functions) but I have a different model. An overflow is an open tube that extends through the bowl to a level ABOVE the normal fuel level. On mine, the drain screw drains into the bottom of said overflow tube.
You should be able to verify this when you have the bowl(s) off.

If I understand the PAIR valve correctly, it is not likely to be the problem.

At this point, if "I" were in your situation, I think I'd just get new needles and valve seats and replace them all while the carbs are apart and probably new floats too. (unless you find the floats badly out of adjustment).
 

·
Registered
Joined
·
6,850 Posts
Just remember the plug tip not the surrounding area is where you look for correct running. Check out my post re the Suzuki GS450e for more info on mixture.
 

·
Registered
Joined
·
26 Posts
Discussion Starter #26
I went to the suzuki shopw and talked to the service manager. I described the problems and what I had done,
He was sure it was the float needle. He told me they get kind of expensive. Its only about a centimeter long though. Stupid expensive specialized parts.
He said they are rbber tipped and he said if they get damaged just a little bit they can leak. When i inspected them the rubber seemed intact and didnt have any significant deformation. To my knowledge they have never been replaced, he said they like to replace them after about 5 years. He said if i brought the bike in they would synchronize the carburetors and everything. Told me parts and serivce could be about $400.
The needle float needles could be as much as $200 fo a set of 4 or less depending on the type.
I can replace the needles but i cant synch carburetors if they need synchronizing.
Do i really need to synch them?
 

·
Premium Member
Joined
·
20,860 Posts
That sounds like a complete load of BS. Check with Blade here before you do anything. $200?!! You could buy new carbs for that! Plus, it's probably a one-hour job to swap them. $200 for labor is a major reaming.
 

·
Super Moderator
Joined
·
12,597 Posts
He said its a 4 hour job to clean, replace the seals and needle and whatnot, synch and everything and it would cost about $400
Given shop labor rates today, that is probably a realistic quote.
Don't forget to change that contaminated oil !!!

If you do the carb work yourself, the sync takes an hour or less on most bikes so that would run you about $80. If it seems to run good, the sync is a desirable thing but not really necessary.
 

·
Registered
Joined
·
2 Posts
Wow all this old post seems to me just like the 2001 Suzuki gsf 1200 Bandit that I just purchased with 21175 miles on it and for $500 because the guy who sold it to me told me that he never could get it running properly and last time he try two years ago the bike let him stranded and pushing...well here I am everything been described plus more. I am Costarrican and had always worked in dirt bikes plus some raptors 700 here in the USA but this 4 in line carbs and this bike my respects. First I got a new battery, take carbs apart and clean and adjust jets and floats (all four were leaking gas) there was 3 gallons of gas mixed with oil in the engine, also the depurator pipe valve was filled with oil gas stinky mixture, set the mix screws at three turns as the manual says, float height at 14 mm to achieve the liner issue, new standard spark plugs, new high flow oil filter, new air filter, new gas petcock rebuilt kit...put everything together and bike fire right up didn't even need the choke but I did notice that it was a lot of black grayish smoke that irritates your eyes pretty fast and bad but anyways I thought well I need to ride this bike to maybe clean out everything and warm it up.
 

·
Registered
Joined
·
2 Posts
The bike runs fine but then I notice it was kind of bogging so come home pull the new spark pugs apart and they were cylinder 1 burning fine and all the other other 3 cylinders really black carbon fouled so I set the mixture screws to 3 and 1/4 of a turn, check the TPS and mount two new ignition coils from another Bandit well the bike didn't improve much except that now all the 4 cylinders seems to be carbon fouled but luckily and thanks to the clear gas filter I was able to check than when the bike start kind to bog it was because less fuel was going to the carbs and when it stalls it was because the fuel completely stopped (mmm very interesting) I do notice that bike had get a Yoshimura exhaust installed but jets were the same manual specify for the carb but anyways bike is extremely rich even at 3 and 1/4 of a turn plus sparks carbon fouled but now I have to figure it out also a gas delivery trouble, gas is fresh the superior quality with 1oz of sea foam per gallon (is sea foam the trouble?) I also found a gas cap valve system totally clog that I take a part and clean really well thinking that that was the solution of one of my troubles but not gas just stop getting in to the carbs when hot more probably and I also have found out that if I put air in to the thank thru the gas cap breather hose I activate the gas flow again and can ride fine until it happens again. About the carbon fouled sparks I even perform a cylinder compression test, they all were fine 135 psi, 140 psi, 150 psi and 145 psi in that order. Now I am running at 3 and 1/2 turns in screw mixture and bike feels great and sounds amazing while stills getting fuel, eliminate this in line filter that the manual actually suggest to install but I realized the petcock already have two filters that were in perfect shape but still running with 4 black carbon fouled spark plugs and a bike that let me stranded any time but not for too long now because all I have to do is removed the set put my finger in one of hoses and blow air thru the other a bingo I get fuel in my carbs to keep going...but really don't know why this bike is doing that I will appreciate any suggestions or how the person that start this post solved his trouble. I haven't sync the carbs but I did got the tool already...but don't think that will solve my issue!
 
21 - 32 of 32 Posts
Top