First Carb Job RE-Done (GSX1100G)

[JMHJ]

I finally got it all tolerably squared away I think. I changed all the O-rings (except the pilot screw ones) this time, including those for the intake boots, and reinstalled them this weekend.

When I first started it though, it would immediately die when I tried to take the choke off. I thought I was in for it again, but I just didn't have the idle adjust screw set right. I'd also forgotten to tighten the clamps on all of the intake boots.

I synched them today as best I could - the middle two carbs pull slightly less vacuum than the outers, and I couldn't make that change with the 3 adjustment screws that are available, at least with the small changes I was making to them - that seems to be by design.

I didn't fine tune the pilot screws, but I opened the outers up to 2 1/2 turns from 2 and it seemed to increase the rpm. The inners were hard to get to (on the underside of the carbs), so I just opened them up to 2 1/2 also with the bike off. It starts very easily and seems to run pretty well like that. 2 3/4 was the most I found any of them turned out when I first removed the factory plugs and checked.

I went ahead and changed the oil AGAIN just to be sure about no gas in that. I've got an old truck with a worn out motor that I may run that through, lol.

Thanks to all for the suggestions, etc. from several weeks ago when I started on this. And thanks again to R. Barr for the o-ring kit... I was able to adapt some from the kit from their intended use to a different use on my specific carbs.

 

[JMHJ]

Just a little update here, and some laughs for the guys who know, and told me how to do it right.

Well, I ended up with a bit of a lean spot in the 1/8-1/4 throttle area. I put a few hundred miles on like that then parked it. I got the Radio Shack washer kit this week ( http://www.thegsresources.com/_forum/showthread.php?t=192957&highlight=shimming+jet+needle ) and tried a little needle shimming before going the pull the carbs again route.

After doing the propane trick to check for air leaks, I added two .81mm x 10mm shims (one at a time) to each needle. Any hesitation/roughness is now virtually gone. That really made a distinct difference; I'm not ready to call it 100% perfect yet though, so I may try one more washer to see what that does. The spot I'd say may need help yet is below 3k rpm, so it may be that motor just isn't happy there - downshifting is noticeably different than with my 850 (it has to be done at higher speeds to stay smooth). I put 80 miles on today and looked at the 1 and 4 plugs a bit ago - they have a light brown hue (which seems just right to me). They were more white when I have looked at them before.

As far as I know, the things I didn't do "right" yet are a full 24hr dip on each carb, and an actual best idle adjustment on each pilot screw (they're all at 2 3/4 out). Oh, and I didn't use new pilot screw o-rings; all the rest are new, but not those. I'd like to have but can't afford finger adjustable screws from here: http://www.factorypro.com/prod_pages/prods17.html . Y'all probably don't have much trouble adjusting them from above.

At any rate, I feel like I'm really close to having it completely sorted out. I've certainly learned some stuff. I've got brake pads and cam cover gaskets ordered (the ones I didn't change after a valve adjustment). The bike is definitely growing on me, and although I'd probably prefer a chain drive, I think it's a from now on keeper if don't run into any financial straits .

 

[jbthomp]

I'd like to have but can't afford finger adjustable screws from here: http://www.factorypro.com/prod_pages/prods17.html . Y'all probably don't have much trouble adjusting them from above.

80$? Wow i think i'll just stick with my pocket screwdriver for that much lol.

 

[JMHJ]

Yeah... these are quite hard to get to from below though, and keep track of how much you're turning them; especially when the engine is hot (there are some oil lines in the way for one, and what looks to be an alternator).

The accessible idle speed screw that's further down on that page is cool too, though not nearly as necessary.

 

[JMHJ]

So I've added a third washer to the needles, just to see what happened. It didn't hurt anything on the low end, but I feel like maybe I lost some of the WOT performance; it's still way powerful, but maybe just a tad less than with only 2 shims.

It's very rideable like it is, but I want to be sure it's 100%. The only mod is a K & N air filter.

I may end up pulling the carbs again, say after this riding season, and doing the extended dip thing on all of them, or maybe investing in an ultrasonic cleaner instead.

I feel like I'm still learning this bike too... I checked last night, and 5k on the tach equates to about 78mph; on my previous one (850), 5k was 65mph. Taking low speed turns in second (which equates to 2k or below sometimes), I feel like this one is lugging a bit, though not in danger of actually stalling, but having to use 1st for 90-degree turns is completely foreign to me too, so...

 

[chuck hahn]

Be easy on the oil withn the K&Ns...too much and its like the choke is partailly on.

 

[JMHJ]

It was on there when I got it, and I haven't looked at yet; probably should have, but it's kind of involved getting it out. I don't think it has that many miles on it.

The bike ran good today; I didn't get on it hard but all the low end stuff seemed nice. It pulled on through the 90-degree turns from as low as 1500rpm in second. Coming off of an 850, I'm used to being able to do low rpms w/o any problem.

I'm going to have to pull the carbs again since I'm just now seeing some slight gas seepage... from the bowl gaskets I would think, since I replaced all the other seals (I can't see it, but there is some on the idle adjustment screw when I mess with it). I'll probably order them tonight from Sirius. And maybe look at their ultrasonic cleaner too; I think I saw one on there for $60.

Oops... they do a carb cleaning service, not sell the machine. I know nothing about those, but that sounded awfully cheap.

 

[JMHJ]

Haven't changed anything yet (edit: except for pulling the carbs again to change the float bowl gaskets, and pilot screw o-rings while I was at it) - I'm riding it just like it was - 2 3/4 out on the pilots and 3 needle shims (thickness? don't remember right off). I have to warm it up for 60sec or so on partial choke, but it runs good after that and gets 31mpg or so. It got high 30s before I shimmed the needles, but that helped the part throttle (0-1/4 or less) roughness problem. I'm not prepared to call it perfect, but it's very rideable.

The pipes are just slightly golden near the motor which worries me a bit, as I wouldn't think it would be lean at all now. I may try fiddling with the pilot screws again with the manometer hooked up before I pull a shim to see if 3 were really necessary.

 

[GSX1000E]

30-31 mpg???? I regularly ride over the suggested speeds and manage a pitiful 42mpg.
What have you done wrong with it??? My fuel mixture screws are 7/8 of a turn out BTW.

 

[JMHJ]

30-31 mpg???? I regularly ride over the suggested speeds and manage a pitiful 42mpg.
What have you done wrong with it??? My fuel mixture screws are 7/8 of a turn out BTW.

I had to shim it up because I didn't soak the carbs all night, lol. I don't know really. The screws were set at from somewhere over 2 to 2 3/4 turns out from the factory.

Given the engine size and bike weight, it didn't seem too out of line to me. My 850 got around 35 (and stunk a little in the later years I had it), but I didn't build that one, lol. Somebody else screwed that one up, if in fact it wasn't tuned just right. I've never seen more than around 40 on any of the three inline fours I've had besides my current one (750, 850, 700).

 

[Nessism]

I'm not familiar with the GSX1100G, but on the early GS CV carbs the thickness of the spacer on top of the clip is what determines needle height. You might want to check the carb rebuild tutorial linked in my signature and on Cliff's website to see if your carbs are similar, and read the details about adjusting the needles. Please disregard if your carbs are different and this comment doesn't apply. Good luck.

 

[robertbarr]

Yeah... these are quite hard to get to from below though, and keep track of how much you're turning them; especially when the engine is hot (there are some oil lines in the way for one, and what looks to be an alternator).

Yep, those are good fun. I finally bought one of those hokey 'Ove Gloves' that they advertise every seven minutes during the Christmas season.... it still takes one bare hand to feel the screw slot, so you get burned about 38 times while you're in there.

 

[GSX1000E]

You might find some help with your carbs here: http://www.gsx1100g.us/
IIRC, the factory setting on the mixture screws calls for 5/8 of a turn out, uses a 1.2/210 air jet and 30 pilot jets with a 120 main jet.
What have you got in YOUR carbs?

 

[JMHJ]

My carbs have a little nylon donut that goes down into the slide and that the clip sits on when the needle is all the way in, with a larger brownish spacer on top of the clip that the spring goes on. I added the washers between the donut and the clip.



I know it virtually got rid of the lean spot I had, but I'm not sure that was the right way to do it. It got rid of some of the gas mileage too, lol.

 

[JMHJ]

You might find some help with your carbs here: http://www.gsx1100g.us/
IIRC, the factory setting on the mixture screws calls for 5/8 of a turn out, uses a 1.2/210 air jet and 30 pilot jets with a 120 main jet.
What have you got in YOUR carbs?

I started to go on there last night, but their registration process is through facebook, which I don't do anymore, so...

I know my mains were 120. I'm pretty sure they hadn't been into before, so the rest of it should have been stock too. The pilots were out way more than that (factory plugs still in place).

I could only get out two of the air jets. I buggered the other two a bit, and just left them in as they were clear. I can only hope I got no shavings down the hole from the slot stripping. I know they'd probably come out with an EZ out, but I didn't have replacements for them at the time.