Carb issues on 83 GS1100E

[chef1366]

You will have to rejet with the pod filters and the bore kit. I went with a Dynojet stage 3 kit.

http://www.dynojet.com/jetkits/motorcycle/suzuki.aspx

The instructions are usually on the lean side so go two steps richer on the needle and try the jets as instructed. They don't come with pilot jets but I'd go up one step on those also.

[distraction628]

why do you all recomend dnyo jet? When you can follow this guide.

http://www.motorcyclecarbs.com/Jetting_Rules_of_Thumb_W43C551.cfm

This has always worked well for me. Plus I don't like slide drilling, slides get spendy!!!
Just my 2cents worth

[oldschoolGS]

Take a look at the bottom of the above page. Needle selection is critical and affects the bike throughtout the entire range. The needle is critical in three areas: taper, diameter, and clip position.

Sure you can replace jets easily, but what you pay for in a Jet Kit are the adjustable needles and a baseline setting that will prevent a lot of headaches. Place a set of aftermarket and stock needles side by side and the difference in all three areas is noticable.

You can shim stock needles with small washers, but you cannot make changes to the needles taper or diameter. Thats why most people buy jet kits. Aftermarket needles are engineered for each specific model and differ from the stock needles in all three areas.

BTW, the above chart is for Keihin FCR's but the principles are the same for CV carbs (they are just not as adjustable as the FCR's).

Good Luck, Ed.

[distraction628]

But you can shim needles to a point. When I was taught we ran dyno and AF meters test and beleave me unless you where racing you would never know the difference. now this is all based on CV carbs. I bet if you took a bike and tuned it the way I do and then tuned it with a jet kit I bet that it would be so close with in 2 to 3 %( which usally means 1-2 hp on bikes under 100hp . Yes there are some carbs from the factory that where set up to run on the leanest side it could and I bet only a full jet kit could help.
I have even retapered needles, fun stuff but it takes time and a lot of trail and error. But once you get it it's so well worth doing it the old way, but it's not for every one. Just my 2cents worth.
Happy new year.
Kevin

[KEITH KRAUSE]

why do you all recomend dnyo jet? When you can follow this guide.

http://www.motorcyclecarbs.com/Jetting_Rules_of_Thumb_W43C551.cfm

This has always worked well for me. Plus I don't like slide drilling, slides get spendy!!!
Just my 2cents worth

If it has worked for you, that's great. But Mr.Zanders suggestions such as "2 jet sizes for individual filters (pods)", which would equal an increase of 5 (each step = 2.5/Mikuni, so 2 x 2.5 =5), isn't even close in my experience. A STEP is 2.5, a SIZE is 5 with Mikuni. He only refers to a size, which he says equals 2.5.
In my experience, pods, even cheaper "Emgo" types, require at least 3 sizes larger (15) or more with Mikuni jets. His suggestions would have very lean results.

[chef1366]

I've tried jetting per Mr. Zanders and it was really lean. I would consider that just a starting point to get the bike running and to do plug chops. That is the only real way for us home mechanics to jet is reading plugs throughout all carbs circuits.
I tried with K&N pod filters, 4-1 Kerker to jet without the Dynojet kit but I always had a stumble off the needle circuit. I did not have an adjustable needle and had to use shims. I feel I got it as close as I could. With the Dynojet I got it to run right with the first install. I did have a buddy who already had a dynojet installed and I used his jetting sequence.
So I have to agree the needle was the part of the kit that made it worth the money.
I wouldn't even begin to know how to taper my own needles.

[brgmiata]

Thanks for the advice. I also noticed that there are fuel stains on the outside of the carburetor now (as if they were flooded). Is this telling me anything like maybe the needle valve is not shutting the fuel off into the float bowl? Or maybe just leaky gaskets? Do the jet kits typically come with new gaskets?

I have not done much with these before.

Thanks.

[chef1366]

The jet kits do not come with gaskets. I'd suggest buying K&L rebuild kits which come with gaskets, new idle mixture screws, float needle and seat with some o-rings. They also come with jets but I use the dynos. They also come with pilot jets but I'd clean and use your old ones unless you have to step up on them and then I'd only use mikuni jets.

georgefix on Ebay is where I got my rebuild kits. Also if you put new float needles and seats in you need to check and adjust your float adjustment.(very important)

[brgmiata]

Got the Dynojet kit and started the job. I am unimpressed with the lousy directions. In the instructions in step 1 it states: “…Using the drill bit provided (DD#32) enlarge the slide lift holes (Fig A). Do not drill the needle hole…”

OK, what’s what? The needle hole I assume is the center hole the needle is in. There are 3 other holes. 1 that goes through and aligns with a small hole in the carb body when assembled. The other 2 are not through holes but are used to align the plastic needle cap. Which ones to drill? All of them? How deep? Why do these have to be drilled at all? 2 of these holes align the plastic needle cap, and on is through. Does this significantly change the slides damping?

Please advise.

[bonanzadave]

This is not the Big Blue machine is it ? Try it with the airbox cover back on. The inlet air hole on my stock airbox is not much bigger than a quarter.

[brgmiata]

No. I just got a dynojet kit after a 80mm overbore on my GS1100E with pod air filters and stock exhaust. The kit states to drill the holes as I stated, but is not clear which holes. I will have to contact dynojet. Nothing ****es me off more than lousy instructions...

[Dink]

Got the Dynojet kit and started the job. I am unimpressed with the lousy directions. In the instructions in step 1 it states: “…Using the drill bit provided (DD#32) enlarge the slide lift holes (Fig A). Do not drill the needle hole…”

OK, what’s what? The needle hole I assume is the center hole the needle is in.Correct There are 3 other holes. 1 that goes through and aligns with a small hole in the carb body when assembled.This is the one you want The other 2 are not through holes but are used to align the plastic needle cap.ignore these Which ones to drill? All of them? How deep? Why do these have to be drilled at all?the jetting allows the motor to respond faster, this needs to be balanced up with slide response 2 of these holes align the plastic needle cap, and on is through. Does this significantly change the slides damping?Yes but in a good way!

Please advise.

Hope this helps
Dink

[brgmiata]

Thanks Dink and Chef1366. Hope this works....I never like performing irreversible ops unless there are plenty of spares....

[chef1366]

Actually I've reversed this procedure by filling the drilled ports with JB weld and redrilled it to the proper size.