Carb/intake boot o-rings

[Tower18]

Hi all,

I'm having huge issues trying to track down what I believe to be an air leak. I've got big time RPM creep when the bike gets hot. The revs will rise to anywhere between 3000 and 4500 rpms (depending on how hot it is) and just sit there unless I hold them down with the clutch.

Through reading, I've heard that there's a pretty good chance this is caused by a bad o-ring on the intake boots. Okay, fine, I ordered some new ones. Well, I'm completely unable to remove those damn screws. I tried dremeling a big slot into them and using a slotted screwdriver, but it just started chewing up the screw like it was butter.

Any ideas? Anyone from Chicago want to come by and help a helpless GS250 owner drill out some stuck screws?

[jbs80106]

Good question!

This is one of my planned winter projects so I'll be waiting for an answer too! Are you replacing both the rubber tubes that go on either side of the carbs AND the o-rings? My 650 had the same issue when I first go her, the PO said to just set the choke a bit more open to solve the problem. It eventually went a way but since returned when I had to remove the carbs to access my starter.

Good luck!

[Tower18]

I am trying the o-rings alone first, and will replace the boot set if necessary. They look mostly okay, and are still pliable, so I'm hoping to not have to.

Opening more choke doesn't work for me, just makes the idle race even higher.

[Nessism]

Use some vice-grips to get a grip on the outside of the outer screw - turn to loosen. After you take out the outside screw, rotate the entire boot counter clockwise to break loose the inner screw. Worked like a champ for my bike.

[Dave8338]

Use some vice-grips to get a grip on the outside of the outer screw - turn to loosen. After you take out the outside screw, rotate the entire boot counter clockwise to break loose the inner screw. Worked like a champ for my bike.

...and if simply rotating the boots does not work, use a block of wood 1x1 about a foot long and at the flange portion of the boot, where it meets the head, tap on the block of wood in a counter clockwise rotation, you may have to repeat the process but they will come loose. (now there's a run-on sentence if I've ever written one) :-D

[Tower18]

I don't understand how vice-grips would help...the screw has a rounded head...nothing to grab.

[Dave8338]

I don't understand how vice-grips would help...the screw has a rounded head...nothing to grab.

Get a good set of the genuine Vice-Grips in the needle nose variety. There is just enough of the head to get a good bite on. Keep in mind...you're going to have to CLAMP down on the heads of the screws. The teeth in the vice grip should leave gouges in the screw head and almost flatten it a bit. It works...I and many others have used this method. Once things are removed, you'll replace the those trashed screws with a fresh set of allan head bolts (stainless won't rust). :twisted:

[82Shafty]

I'm glad that my 1100 had allens instead of pan head.

I've used brake cleaner to locate hard to diagnose air leaks... I must warn you it is highly flammable!!!!!!

You may also use propane to locate a leak or I have even used soapy water in a little spray bottle.

Are you north side or south side?

[82Shafty]

Worst case is cut the head off and remove the boots... heat the screw area up and use vise grips to lock onto the stud portion.

[mortation]

I had this issue on some of my boots to. I cut the head off of the bolt to pull the boot off which released the pressure, clamped some vice grips on to the stem and rolled it out.

When you replace the bolts dont go with allen either. Use Flange head hex nuts. The look pretty and they ALWAYS come off lol.

[Tower18]

I'm glad that my 1100 had allens instead of pan head.

I've used brake cleaner to locate hard to diagnose air leaks... I must warn you it is highly flammable!!!!!!

You may also use propane to locate a leak or I have even used soapy water in a little spray bottle.

Are you north side or south side?

N/NW Side, Western and Lawrence.

I'll try the vice grips thing as mentioned, and look into just sawing off the heads.

[Matchless]

There are many ways to loosen those screws. I have used an air impact wrench with a "Japanese Philips" bit (bit from the impact screwdriver) and it seems to work most of the time. You can also cut the sides off the screw head with the Dremel to give a more flat surface for a small spanner to grip or for the vice grip. The last resort is to cut off the head carefully. It is easy to damage the rubber due to a slip or while cutting the screw.
For removing the screws many people weld up a Japanese Philips bit to a T handle and can then put enough pressure to turn the screws without it slipping easily, but you must have a perfect fitting bit and good condition slots on the screws to start with.
I have found that with stubborn screws you always need to use the screwdriver with the longest handle to minimise slip. Using a short handle virtually guarantees a slip and messing up of the slot.

[Tower18]

Speaking of using the screw with the longest handle, how do you guys remove the airbox? I can't seem to figure out how to do it without removing the rear fender, etc., and this really limits the room in there. I don't know how much room is on the larger bikes, but it's quite cramped in the 250.

[t3rmin]

I've got those screws out using a well-fitting bit in a 1/4" socket in a ratchet. The ratchet gives the needed leverage and gives you room to push like heck while turning to keep the bit seated. I find short, hard turns break the screws loose the best. But if you've dremeled the screws you're a little beyond this, so I guess this is advice for next time (of course you'll have replaced them with allen screws by then, right?). Good luck.

[Nessism]

I removed all four boots on my '79 using the vice-grips on the screw method - took less than 10 minutes. I learned to use this method after struggling to get at the screws using an impact and/or shorty screwdriver. The vice-grips give lots of leverage with the only tricky part being getting a good grip on the outside edge of the screw.