1979 GS750e Boiling fuel?

[Northern Mike]

I'll admit off the hope, know enough about carbs to be dangerous...

Now that that is out of the way, picked up a 1979 GS750e last Friday. Been cleaning it up the past week, and just put the temp plate on it and insurance to get the safety done.
In the driveway, it ran reasonably fine. The guy I bought it from mentioned when I got there that he had ran seafoam through the bike to clean the carbs. This was a 3 hour one way drive to get the bike. When I got home and opened the air box, I found the air filter soaked and sticky (thick blue crap).

Anyway, cleaned and dried the filter, and on the road this morning for the first time. From the house, ran good. After about 20 minutes of mix hwy and city, I noticed huge hesitation around 2K RPM, as if I'm running on 3 for a instant or so. Limped home and checked it over.
New plugs are fairly black, not the tan I was hoping for.
Pulled the air breather and noticed a fair bit of moisture in and around the intake tubes.
Started the bike with breather box cover off and noticed the #1(?) carb was smoking/steam from intake.
Hard to tell if it reduces with RPM or if the other carbs are sucking it in.
Here is a short video I took of it.

Thoughts?
I'm guessing the jets may be gummed up but as I stated in the beginning, know enough to be dangerous, not enough to own my own bike shop.

[SocialAnomaly99]

Could that maybe be steam coming from the crankcase vent(the tube that runs from the valve cover to the top of the airbox)?

[Northern Mike]

Could that maybe be steam coming from the crankcase vent(the tube that runs from the valve cover to the top of the airbox)?

That is very possible. I should have considered that, but with the hesitation appearing after being run for 16km as per the trip meter at around 2k RPM, I had thought it may be related.
I'm going to be going out tonight with the wife for a ride (just got her bike put together, safetied and running like a top). Will do some hwy running so it can clear out all the junk and hope the wife doesn't have to go get the truck to pick me up.
Until the hesitation started, the bike ran really good and strong. Not use to the inline 4s any more as the bikes I have been working on the last couple have all been V twins. kind of missing the low down torque feeling but do like this bike much better then a cruiser.

Other then plugs, new oil and running a fresh tank of good fuel through it, any other suggestions before I start poking the carbs? Have a new air filter on order as although I did get this one mostly clean, I feel it is still a bit tacky from that blue crap (guessing seafoam).

[Brendan W]

Sooner or later all us noobs have to deal with this...................

http://www.thegsresources.com/_forum/showthread.php?171846-Top-10-Newbie-Mistakes

[SocialAnomaly99]

Not sure that the "blue crap" is Seafoam. Seafoam (the seafoam I use anyway) is clear. I don't know what that blue crap could be. The hesitation could unfortunately be a thousand different things. Could be valves, carbs, electrical, all kinds of stuff.

[Northern Mike]

Sooner or later all us noobs have to deal with this...................
http://www.thegsresources.com/_forum...ewbie-Mistakes

Thank you for the link. This forum will be a great tool for me as each bike has it's own funny corks.

Not sure that the "blue crap" is Seafoam. Seafoam (the seafoam I use anyway) is clear. I don't know what that blue crap could be. The hesitation could unfortunately be a thousand different things. Could be valves, carbs, electrical, all kinds of stuff.

I've never used seafoam. I've always stayed away from additives other then fuel stabilizer in a full tank when storing for the winter.

As for the hesitation, it's only after warmed up completely. Warm it up a bit in the driveway before leaving, and it runs fine. It's not super warm here (15'C), but after a bit of riding, it starts, and only around that low RPM, even when cruising at a constant speed in town, ~2500RPM is where it starts running rough. Below or above is fine.
I would have gone straight to the sparkplug wires as the owner before the one I bought it from (less then a year ago), had changed the wires to yellow NGK 7MM wires, but I would have guessed it would have ran like crap until it was warmed up, then ran better. The long shot (probably not the issue, but catchy subject) of boiling fuel is kind of how its acting.

I did note, the previous owner only put ~1000km on the bike in the year he had it and the tank was almost empty when I got it. Going to hope its junky fuel and it clears up a bit before doing the orings and adjustments.

[Northern Mike]

Really quick update...
Ran it about 50km now, half and half hwy and in town. The hesitation is lessening a bit, but is still there. New plugs in #1 is still pretty dark, but not as bad as previous. #2 and #3 plug look good and #4 is a hair darker then I would like (did previously swap #1 and #4 after my first ride to see if I could save the plug from being fouled).
Can definitely say I'm falling for this bike. Will update once I go through a full tank of fuel. Hoping it just needs a good flush of fuel through it and some mileage.

[SocialAnomaly99]

Nice. That's good news. Grab another can of seafoam and run it with your new tank of gas. The stuff works very well. Add some to your crank case too if you're doing an oil change in the near future.

[Big T]

Well, you can rule out boiling fuel

The Newbie thread above will point you to:
valve adjustment
carb synchronization
mixture screw adjustment

as starting points. Since you don't know when/if those 3 things have been done, I'd start there

Since 2 of your plugs look good, you're 1/2 way there already!

[Northern Mike]

Since 2 of your plugs look good, you're 1/2 way there already!

Love the optimism.

Was planning to go after the carb adjustments first as they are the easiest to do without pulling the bike apart.
The valve adjustment will be coming. The valve cover (?) has been off in more recent times (not the last year) as it has a newer gasket on it with the bracing still needing to be cut off.

May be a bit optimistic myself in hoping I can get it running strong enough to make the summer, then do a full tear down over the winter. With hopefully a new shop to work out of, I'm going to put my composite fabrication to the ultimate test while rebuilding both motors on our bikes.

[Brendan W]

Cleaning, bench sync and baseline adjustments maybe but I wouldn't attempt getting the carbs in step until the valves were checked. No point if the pots are sucking the wrong amount of air.

[Northern Mike]

Cleaning, bench sync and baseline adjustments maybe but I wouldn't attempt getting the carbs in step until the valves were checked. No point if the pots are sucking the wrong amount of air.

The bike did come with a service manual. Will have to sit down with it tonight and a few beer to review it.
Valve adjustment would almost make sense given everything else.

[Brendan W]

The bike did come with a service manual. Will have to sit down with it tonight and a few beer to review it.
Valve adjustment would almost make sense given everything else.

In case you haven't yet found it http://members.dslextreme.com/users/bikecliff/
I would have a look in at the valves fairly soon. The clearances are small and many have left it too late and burned a valve.

[Big T]

In case you haven't yet found it http://members.dslextreme.com/users/bikecliff/
I would have a look in at the valves fairly soon. The clearances are small and many have left it too late and burned a valve.

Mike, go poke around in that site. You'll find both a factory service manual for your bike and the correct way to check the valve clearances and a lot of other stuff, the accumulated knowledge of this site, as it were.

[eil]

Other then plugs, new oil and running a fresh tank of good fuel through it, any other suggestions before I start poking the carbs? Have a new air filter on order as although I did get this one mostly clean, I feel it is still a bit tacky from that blue crap (guessing seafoam).

That "blue crap" is probably air filter oil and it was supposed to be there. It's tacky because the foam filter will only catch very large particles, the oil catches dirt and dust as well.

Go to the links that Brendan W posted, clean/adjust the carbs the right way, re-oil the filter, and the bike will probably run great.