1981 GS 750e carb float sticking? Overflowing

[cmslevin]

Thanks for the advice phred, don?t know a good looking toyota nessism. The oil also had some gas in it before, we ran seafoam through it, with a new oil filter and no gas is getting in the oil. Starts up quick, idles at 3, a little bit is coming out the overflow tube underneath while it?s running, in addition to the one inside carb (only) that has the same little drip. Plan on starting it up today with the seafoam that has been sitting in it, and running it hard down the road, I don?t expect it to ?clear the crap out?, but can?t hurt. I also believe the carb(s) will need to come off, everyone here has been helpful, thanks.

 

[Guest]

You will not have much luck with Seafoam or carburetor cleaner. Listen to the good advise that has been given and soak your carburetors for 24 hrs. in carburetor cleaner. Replace the gaskets and O-rings and follow the rebuild instructions you can find on this site. There are no short cuts. You have gas leaking into your oil a possible bad petcock and many years of maintenance to catch up on. The GS series is tough runs, great until It doesn't. Park it, do the maintenance and it will run like a new bike for many years. Don't do the maintenance and you will never know why so many like these bikes. I took Nessism's advice and got the Toyota. '88 4runner I think they called it a beach runner back in the day. Will make a nice vehicle to trailer my bike to events. The last one, basically riding 4 days straight was a little rough on me since I've turned 70.

 

[cmslevin]

Thank you, I was hoping you would comment given you basically have the big brother to my bike, my dad actually had an 82 gs1100e. I ran it good and hard today and it’s the best I’ve ridden it so far, didn’t leak afterwards, we will check again tomorrow, but after we had the seafoam n carb cleaner through it, from lat night, it didn’t leak either. If we check tomorrow and see no gas going anywhere it shouldn’t, the idle will be the only issue, time will tell though, must be patient of course. Not really into nissans too much haha.

 

[cmslevin]

I do however want to make sure anything that controls the idle is correct as well, I have heard about the pilot screws. And how O rings may need replaced. What?s is your opinion on that?

 

[cmslevin]

I saw a link by nessesism about replacing O rings in the intake boots, but I believe my 81gs750e has gaskets instead, high idle, it seems like that may be the issue, all in all what does it require to replace those, carbs come off?

 

[tom203]

Sure, those old things might be leaking.. But maybe you got the idle stop screw turned way up to compensate for clogged idle circuits. Carb rack removal is in your future..might as well bite the bullet and listen to folks who have been down same road.

https://www.partsoutlaw.com/oemparts/a/suz/50d4007ff8700230d8b4e2c0/cylinder-head

 

[Darin Jordan]

I just experienced this. It's been about 6 years or so since a total rebuild, using K&S parts. At first thought Needle and Seat, but when I took the carbs OFF the bike and inspected, I found that the gaskets had swelled up and gotten wider, and that the #3 float was dragging on the gasket, holding it open.

Here is a picture showing the differences, with a new, OEM Mikuni gasket on the right.

 

[Darin Jordan]

Here is a comparison of the two. Not sure the K&S Gaskets started out this way. May have been a combination of too many float-bowl remove/replaces while working on getting the bike jetted (w/ PODs... yeah, I know... ), or maybe the high amounts of Ethanol in the fuel these days.

 

[cmslevin]

Interesting thanks

 

[Darin Jordan]

Here is what I found when I removed the float bowls:

 

[Nessism]

I just experienced this. It's been about 6 years or so since a total rebuild, using K&S parts. At first thought Needle and Seat, but when I took the carbs OFF the bike and inspected, I found that the gaskets had swelled up and gotten wider, and that the #3 float was dragging on the gasket, holding it open.

Here is a picture showing the differences, with a new, OEM Mikuni gasket on the right.

View attachment 54907

Crap aftermarket gaskets. All too common with aftermarket parts, particularly carb parts. Almost always inferior to OEM.

 

[leftlostcommonsense]

I understand the worry you have about carburetors. I'm new to bikes too and had never touched a carb on anything before digging into mine a few months ago when I got my bike that had set for 5 or 6 years in the weather. I read and then got right to it and didn't mess anything up, you can too. They are very sophisticated in their working but very simple in their build and a good read on how they work and how to take them apart will give you an idea as to what it takes. Then once you start and go to taking them apart you will see they are very easy to disassemble not to mention very simple devices. There is very little you can mess up unless you use extreme force or extreme ignorance. You found this forum so I'm confident you can pull apart carbs and remember how to put them back together. It's only natural to be nervous about something you've never done especially when it comes to something as misunderstood as carbs. They're literally 40 year old pieces of tech so they're not that sophisticated or technical though. Only do one at a time, take your time and for the love of GOD do it yourself. Don't trust your bike to someone else especially someone you pay to fix it because problems = money to them and they're not the ones stranded or hurt when things go wrong. Don't be scared, make it your b****...Be aware and ready to replace intakes too once you've pulled the carbs a time or 2 unless they've been replaced recently. At the very least you will need to replace o-rings if not the whole boots. I don't know what kind of shape your bike is in and I didn't believe it either when people told me this but expect to spend anywhere from 500-1000 to get the bike in perfect working condition that is not only safe but reliable too. Lol I had no idea how I'd be able to spend that much on a perfectly working bike in order to get it right but I found out pretty quick things that don't appear to have a problem really are the cause of your problem. Good luck

 

[cmslevin]

Thanks, thanks for the heads up on how conflicting, my bike is no longer leaking after I took it out the other day, not into oil, not from carb, not from overflow hose underneath, just a high idle right now. I was thinking possibly the idle screw, but we would never mess with that considering my bike at one point actually idled ok, and on my run yesterday it can to 1000 about 3 times.

 

[cmslevin]

It is just a beautiful bike, I won?t give up on it, and I definitely want to take the correct steps, which there are many tutorials online here that look helpful!

 

[cmslevin]

View attachment 54910 It is definitely not a hunk of junk, the reason it sat for so long before me was due to a previous owner who passed away. But that was two owners ago, it was road the year before I acquired it.

 

[Guest]

High Idle could be a vacuum leak at the head where the carburetors attach, the boots or another O-ring failing. Could be the vacuum hose to the petcock. You never will figure it out until you rebuild the carburetors replace the O-rings and gaskets, inspect your diaphragms for pin holes or cracks and establish a baseline from where the carburetors can be dialed in. Most of us started out wanting to ride but not wanting to learn what it takes to get one of these old bikes back in proper shape to ride. That just does not work and most shops do not have the expertise or will to put the time in to do the job right. You would not want to pay that bill anyway if they did. I knew nothing of the VM carburetors on my bike when I started but I can rebuild them easily now for very little. Take the time to learn and it will pay you back in the long run. (use factory parts)

 

[Darin Jordan]

Got her back together last night with the new, OEM, gaskets and needle/seat assemblies. Set the float levels to 22.0mm.

No leaks, and runs like a fine watch. No more float-bowl vent leaking!!

 

[cmslevin]

Happy rider

Happy rider

$600 later, from a shop with great reviews from friends and online and it is like day and night. Only 9k on it, this shop said the idiot that was in there before not only put the wrong size jets in there, but failed to even clean it thoroughly and put the necessary parts the bike required, into the bike.

 

[posplayr]

$600 later, from a shop with great reviews from friends and online and it is like day and night. Only 9k on it, this shop said the idiot that was in there before not only put the wrong size jets in there, but failed to even clean it thoroughly and put the necessary parts the bike required, into the bike.

This should be rule number one of the newbie mistakes, "Never trust anything from a Previous Owner".

 

[cmslevin]

Oh I didn’t trust much from the previous owner too much, figured the running aspect would be a little bit of a project, just recommend doing research on the places you take anything to. Because it wasn’t the owner that was in there, I suppose he could have been, but the 1st shop we took it to was a sham, and they were in the carbs.