'80 GS250t- carb rebuild, now idles great, Boggs w/any throttle

[jdvorchak]

Seems you are out of ideas. I'd be temped to treat this like any new to me bike. Realizing that it's not running good I'd pull the carbs apart and dip them. Treat this just like you've never seen the bike before. Remove all of the carb parts, you can, and clean it like a bike that's been sitting for 5 years.

At this point you think you got an idea about what's wrong and that preconceived notion could cloud your judgement.

[MatBirch]

Seems you are out of ideas. I'd be temped to treat this like any new to me bike. Realizing that it's not running good I'd pull the carbs apart and dip them. Treat this just like you've never seen the bike before. Remove all of the carb parts, you can, and clean it like a bike that's been sitting for 5 years.

At this point you think you got an idea about what's wrong and that preconceived notion could cloud your judgement.

Welp- can't disagree with you. I have the first one back stripped down and in the dip. The can is heating on the wood stove in the shop.
Starting over! Yay!

[MatBirch]

On the plus side, I have long been fighting with my wife's 550 a bit as well. Once I get this licked, I'm gonna tear back into those carbs as well. I bet didn't do as good of a job as I thought on those either, and this episode is giving me good direction...

[jdvorchak]

This last summer I worked on a GS1100 for a guy and he brought it to me saying the carbs needed to be cleaned. I test rode it and yeah it was only running on 2 or 3 cylinders. I didn't want to just pull the carbs because that would cost the guy more money he didn't have. So I started at step one and checked for spark while running a compression test. Found that #1 and #4 had no spark. Started looking and found that one of the primary wires to the left side coil had come out of it's crimp on connector. A PO had put aftermarket coils on it and didn't do a great job of crimping on the connectors. I redid the crimp on connectors and he left with a smile on his face. For the first time since he'd owned it, it was running on all 4.

I guess the moral of the story is when you're baffled go back to the basics.

[MatBirch]

Ok-
I pretty well have the problem figured out. The passages under the diaphragm are plugged SOLID! One goes to the choke circuit, one goes to the pilot screw circuit. Both snake their way through cross-drilled passages and change direction deep inside the body. I cannot get anything through those passages around the corners. What can I do to get through these passages??? I have now dipped in Berryman's twice, once for about 6 hours, once for 24 hrs.
I know I can get it if I pull one or two of the press fit block off plugs. I'm nearly willing to buy an ultrasonic cleaner. It would have to be the Harbor Freight one due to price and availability. I'm just not real confident that it will help much.

[JJ]

Yes, I think an ultrasonic cleaner, along with wire and compressed air would do it.

[jdvorchak]

At this point I think you have one more option and that is to squirt PB Blaster or similar penetrating oil, into the passage. Let it soak an hour or so and use compressed air. I've had good luck with PB on such items and it will penetrate to the clog. Just keep the PB away from rubber parts. It eats rubber.

The sonic cleaner would have a good chance of working and having one would be a handy thing.
Good luck and hope you get it sorted out soon.

[Wallowgreen]

As you say, the capillary passages are drilled during the manufacturing process and consist of a number of intersecting straight sections. Necessary but redundant external entry points for the drill are then sealed by pressing brass balls into the body. I agree, it will be difficult to coax anything through those passages and I've not heard of anyone removing the ball plugs then successfully refitting them.

Do persist with the cleaning and make sure you can squirt cleaner spray through those passages before you rebuild but my experience has shown there is a point (at least for me) where it's just quicker and easier to look for a set from a running bike and go from there.

Good luck!

[jdvorchak]

I agree with Wallowgreen there comes a time when a new set of carbs is warranted. But I am the type that would, once I got a working replacment, try to drill out that brass ball, finish cleaning them just to see if could be done. I would think that JB weld and a small machine screw would plug that hole back up nicely.