GS250 idles but won't rev

[Zwaylo]

Hi, this is my first post. I recently bought a really clean 1980 gs250t and am having issues with it. I cleaned the carburetors and now the bike runs. The issue I am having is that the bike starts easily and idles but will not accept throttle. The bike will rev by pulling the choke in and out but that is it. I assume this is a fuel mixture problem, is there an air/fuel mixture screw? Any help is appreciated. Thanks

 

[Dave8338]

Welcome abord! You're correct on a fuel ratio problem, you need more fuel. Have you torn the carbs down and cleaned them, replaced all the orings? If not, do your bike a favor and park it until you do. It is the only way you will get to run right and until then...you're just beating a dead horse.

BassCliff will be along to role out the Red Carpet and get you up to speed with all the needed links and such.

Again, WELCOME to the GSR. Your bike thanks you for coming here first! :-\\\

 

[Zwaylo]

Yeah I tore the carbs down and cleaned it, all the jets were very clean and there was almost no fuel residue in the carbs, however I did not replace the seals in the carb. Thanks for the welcome!

 

[Larry D]

Welcome !!!!

It sounds like you may have an air leak. How do the connections from the airbox to the cylinder head look ? Is the airbox itself sealed well ?

 

[Zwaylo]

I just double checked the seals between the airbox and the cylinder head and the airbox itself and they all are sealed well and are like new.

 

[Calvin Blackmore]

I just double checked the seals between the airbox and the cylinder head and the airbox itself and they all are sealed well and are like new.

you removed the carbs and checked?
a visual inspection witht he carbs mounted will not reveal anything.

the orings get brittle and hard and fail to seal properly over time.

new ones are plump and pliable

 

[Zwaylo]

Yes, I had the carbs off this morning to clean them. Before I reinstalled them I checked the boots between the carbs and the head, and the boots between the airbox and the carbs. Both were soft with no cracking present.

 

[Larry D]

I just double checked the seals between the airbox and the cylinder head and the airbox itself and they all are sealed well and are like new.

Here's a pic of the boots off my GK. As you can see, the orings are squashed and useless. Also the airbox needs to sealed well. Most here use the appropriate weatherstripping found at a local hardware store. You can't tell until you take them off. Which can be difficult, once you get them off, replace those silly phillips head screws with some socket head or hex head bolts.

Email or PM Robert Barr and see if he has the orings for your carbs and the orings for you intake boots.

http://www.cycleorings.com/

 

[Zwaylo]

That is a good possiblilty, I did not check the seals between the boots and the cylinder itself. I'll work on pulling those off. Also, I noticed that one of the seals is torn between the left side carburetor and the airbox. What all seals should be replaced do you think? The bike hasn't been on the road since '88 so it wouldnt hurt to install new seals

 

[BassCliff]

Greetings and Salutations!!

Greetings and Salutations!!

Hi Mr. Zwaylo,

Sorry I'm a little late with my "Howdy!"

There's a lot of information in the two links below. Knowledge is power.

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

 

[Zwaylo]

Hi BassCliff, thanks for the welcome! I have attached a pic of my 1980 gs250. The bike has 3762 original miles, which I picked up for $500 last week. I'll begin reading through your links to more familiarize myself.

 

[Larry D]

Nice, nice bike !! Looks really clean....for 5 bills...good job !!!

That's the best thing you can do. Spend a few days reading through Cliff's site and here and educate yourself some. You'll realize that regardless of size, most of these older bikes need the same maintenance to keep them running well.

 

[Calvin Blackmore]

Hi BassCliff, thanks for the welcome! I have attached a pic of my 1980 gs250. The bike has 3762 original miles, which I picked up for $500 last week. I'll begin reading through your links to more familiarize myself.

beautiful thats almost show room condition
did the PO keep it in his living room?

 

[Zwaylo]

Thanks! Ya it is pretty much in showroom condition, with the exception of one tiny dent in the tank which should pop out easily. The inside of the tank looks brand new too. The previous owner actually kept it in his finished basement for the last 20 years.

 

[BassCliff]

Hi Mr. Zwaylo,

Wow! That is a great looking bike. Congratulations.

Thank you for your indulgence,

BassCliff

 

[exbellicus]

I'd get that sucker running well and turn her around to the ebay collectors!

 

[Zwaylo]

I thought about that too, what are these bikes worth in good shape?

 

[Dave8338]

That is sooooooooo purdy, I... I think I'm going to tear up.

Sweet score!

Keep it, care for it, and enjoy it! Let someone else sell a collector bike! :-\\\

 

[Wallowgreen]

Bloody site better looking than ours at the mo

Just done the carbs on the '80 250T we're working on, like Larry said, get a set of standard BS o-rings from Robert at cycleorings.com. You'll have some spare but everything you need is in the set. As for the intake boot o-rings, it wasn't clear to me what size to get so I went with OEM from the parts list and measured them before I fitted them so I would know if there was a next time. I'll have to look around and find the measurement to post it up later.

Somebody, think that was Larry too, mentioned the airbox. I don't think you have much to worry about there. The airbox on these machines are not the same as larger GS bikes. They are an enclosed box except for the intake at the top, the boots to the carbs and the breather. Check the filter element is in good nick, by preference change it, and the seal strips on the lid under the seat. Other than that, I didnt' find anything else to worry about with ours other than the mice living in it of course.

I've been gathering some spares for this machine so give me a shout if you need something, never know, I might just have one.

Good luck with getting her running.

EDIT: beware the clutch push rod oil seal !!!

 

[Zwaylo]

Thanks for the good comments everyone! Just ordered new intake boots, o-rings for the intake boots, and the rubber o-rings that connect between the airbox the carbs. Are there any others that I should replace too?