• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Seafoam cause poor running?

Nessism

Nessism

Forum LongTimer
Super Site Supporter
Past Site Supporter
TGSR Superstar
My ?81 550 is a full time garage queen since I haven?t gotten the title business sorted out yet. It sat for a lot of years before bought it and needed the typical carb rebuild which I did about a year ago. I?ve been pretty bad about running it regularly so I recently dumped some Seafoam in the gas because the label says it stabilizes the gas. Shortly afterward doing this the engine started running poorly so I pulled the carbs and did a quick spritz out which took care of the immediate problem.

The bike currently runs good other than a hanging idle problem; rpm does not drop as quickly as it should and when blipping the throttle it tends to hang at about 2000 rpm. If I set the idle speed lower, it tends to go too low and stall ? can?t find a happy medium.

The carb boots are nice and soft and there are fresh O-rings installed so I don?t think this is a vacuum leak issue. Bike is 100% stock. I?ve check the throttle linkage closely and did a vacuum sync ? set the two inner cylinders slightly lower than the outers. Idle mixture screws are set at 2 turns (can?t detect any idle speed variation when adjusting).

My understanding is that a lean mixture leads to a hunting idle. I really don?t understand what has changed on the bike other than the Seafoam. Does it mess up the mixture that much to cause the problems I?ve described? I?m going to dump the gas this week and try with fresh stuff but any input is appreciated.
 
Just a thought. But I would run the tank of gas in it. The fill up with your regular brand. Give the sea-foam a chance to clean out the combustion chambers.

IMHO

Tony
 
Heck, everything I've put Sea Foam in has responed nicely within just a few minutes. The idle speed went up on the bike and my mowers have turned into grass eating machines. :)

It sounds like you have taken all the quick measures to make things right. Have you checked your plugs for possible mixture issues? If you haven't actually rebuilt/thoroughly cleaned the carbs internally, you might find your issue there. The float needles, seats, and gaskets wear and deteriorate with time and may need replacing. I've found that needles have been required on my GS every 30K miles or so as they can leak a little gas, raising the fuel level in the bowls and causing richness - even flooding the crankcase with gas 1 time.

Oh, if the gas in the tank is more than a month old - dump it and refill with fresh gas. Adding the Seafoam after the gas has already deteriorated won't do any good.
 
I’ve been pretty bad about running it regularly
Click to expand...

This is your problem. I use Stabil in the winter and run my bike at least every other week to keep the fuel moving. You will have less problems if you at least fire it over every once in a while.

~Adam
 
You may still have clogged idle circuits, making things lean. The SeaFoam may have loosened some crap which flowed downstream and clogged something...?

Also consider that lots of SeaFoam in the tank may change the fuel composition enough to alter engine behavior. I noticed this the other day using a bunch of water remover (alcohol) and MMO in the tank. Once I ran it through and put in fresh gas, the bike ran more normal. So although it had a good effect in the long run, while it was still being burned through, things weren't quite right.
 
The bike started to run worse after adding the Seafoam. I'm not sure if it caused the problem by loosening crud but I subsuquently pulled the carbs and sprayed them out with carb cleaner. Bike ran better but I can not get rid of the hanging idle - thus my reason for this thread.

I'm going to change the gas and see what happens.
 
Well I'm just suggesting maybe the SeaFoam knocked something loose that wasn't cleared by a quick spray out. Did you poke out the little idle holes in the throat? Spray hard through pilot jet, main jet, and air jets?

Just bouncin' stuff off ya. ;-)
 
If you get too much Seafoam to your amount of gas, it will run poorly. There may be some smoke though. If you pour it directly in the intake like I can on my M750, the motor will almost stall. Most likely, the combination of not 100% gas with a bit too much Seafoam in the fuel AND the crud being knocked loose is just making it a little grumpy ~

JM
 
Use it or lose it!

Use it or lose it!

Mr. Nessism,

Whenever I use Seafoam I like to put it in the tank just before a long trip when I know I will use most, if not all, of that tank riding that day or the next. Then I fill up with regular gas. Seafoam has always helped. I concur with Mr. t3rmin's speculation that debris may have dislodged and gotten stuck somewhere else. This could happen if you run a "Seafoamed" tank for just a little while. You have to run it for a good long time and let it do its "magic". \\:D/

Thank you for your indulgence,

BassCliff
 
Last edited:
t3rmin said:
Well I'm just suggesting maybe the SeaFoam knocked something loose that wasn't cleared by a quick spray out. Did you poke out the little idle holes in the throat? Spray hard through pilot jet, main jet, and air jets?

Just bouncin' stuff off ya. ;-)
Click to expand...

I removed the pilot jets and poked them through with a wire - none were plugged. Same thing for the mains. I didn't do anything with the air jets. Bike runs pretty well but has a hint of low speed leanness. Air filter is brand new as are the plugs.

Thanks for all the suggestions.
 
I'd take zuzu's advice and tell you to run at least a tank full thru the bike, but understand the title thing might make that a little hard to do. Drain, put the old gas in your car and refill the tank with Sta-bil-ized gas.
 
Nessism,

I've had similar issues with my 550. I see that you mentioned that your mixture screws 2 turns out. Accourding to this site, in the carb setting section, the factory settings are 3.5 turns out. This seems to be where mine are happiest. Perhaps your running a bit lean now which might explain the slow return to idle.
 
smagnusen said:
Nessism,

I've had similar issues with my 550. I see that you mentioned that your mixture screws 2 turns out. Accourding to this site, in the carb setting section, the factory settings are 3.5 turns out. This seems to be where mine are happiest. Perhaps your running a bit lean now which might explain the slow return to idle.
Click to expand...

Do you have a link to where you read 3.5 turns? I always that they were supposed to be in the 2 turn range. :confused:
 
Nessism said:
I removed the pilot jets and poked them through with a wire - none were plugged. Same thing for the mains. I didn't do anything with the air jets. Bike runs pretty well but has a hint of low speed leanness. Air filter is brand new as are the plugs.

Thanks for all the suggestions.
Click to expand...
Check your bands on the intake and airbox boots to make sure they are snug and also check the intake boot screw to see if they are torqued the same.It sounds like you may have a air leak.Also check your airbox to make sure it is sealed properly.Clean your plugs and air filter.
 
You may have a gunked up fuel filter - the seafoam could have washed all the resin and rust in your tank which made a beeline to your filter and gunked it up. Just my 2 cents.
 
Sounds like what mine did when I tried adjusting the mixture screws back to lean (1.5 turns out). My bike won't idle properly unless it's at 3 turns out!!

Not sure why yet :(
 
On a more positive note, I put some SeaFoam in the 700 and it's idling better today. ;-)
 
How old was that tank of gas youput the seafoam in? I would bet that you had a problem before the seafoam. if you pull and clean the carbs right the first time, you don't have to do it everytime you let the bike sit. There are thousands of people who winter their bikes for half a year every year for 25 years. Drain your tank clean out the petcock, if you have already cleaned the carbs twice, just take off the bowls and clean the float valve screens, replace your plugs and ride your bike.
 
Clone said:
How old was that tank of gas youput the seafoam in? I would bet that you had a problem before the seafoam. if you pull and clean the carbs right the first time, you don't have to do it everytime you let the bike sit. There are thousands of people who winter their bikes for half a year every year for 25 years. Drain your tank clean out the petcock, if you have already cleaned the carbs twice, just take off the bowls and clean the float valve screens, replace your plugs and ride your bike.
Click to expand...

Tank is the same age as the rest of the bike, 25 years. It's clean though so I'm not worried about that.

After reading though all the good suggestions I think the problem could be either the Seafoam in the gas has changed the gas's characteristics in some way or I have some debris in the pilot screw passages. I didn't get a chance to change the gas today but I will tomorrow. And spray out the pilot circuit while I'm at it. The carbs didn't look that bad when I had them off recently and the bike really does run pretty well. Last possibility is a vacuum leak but everything looks well sealed. Sprayed WD-40 on everything while the bike was running and nothing. Even tried the propane gas around the clamps and still nothing.

At any rate, I'll report back tomorrow after doing some more work on the bike.
 
You must log in or register to reply here.
Back
Top