New member introduction/gs1000g jetting

[Guest]

Hey everyone, I'm new to the forum, I've been reading info from here for a while now i thought I'd finally make an account since this website so much more useful than any GS Facebook pages.. recently picked up this 1980 gs1000g, the bike it self is super clean and I'm super stoked to own it. I have yet to find a spec of rust on this thing, its unbelievable how well it has held up over 40 years! I bought it from a guy in Dallas who bought it all the way up in Iowa as a barn find, literally. Ill be going back to a stock seat or maybe a custom one, ill deal with that later on! Right now I need to figure out this lean condition! The carbs were rebuilt but I believe they need bigger main jets. The bike idles smooth, fires on all 4 and drive ability is good but it is gutless and I can't get it above about 5k rpm at all. It back fires a bit and plugs are white/grey with about 15 miles on them. Has vance and hines 4 into 1 exhaust and dyna ignition on it. I've read stock main jets are 114, based off info from a couple other post i thought about trying a 125... I'd like some feedback though, I couldn't find much info on this, and tuning carbs is not something I've ever done. I've rebuilt a few on old four wheelers but that's about it. Any advice?

https://www.flickr.com/photos/188715436@N07/shares/ZS31c1

[Redman]

20200530_082634 by Joshua Haltom, on Flickr

[Redman]

Welcome to THeGSR, Josh.

I am not the one to have specific advise for your carb jetting. But can welcome you to TheGSR.

Good condition G there.
Yah, those seats maybe functional for some purposes, but just look like dont belong on that bike.

[Grimly]

Chrome tending towards purple on the header pipes is not good. Often a sign of weak mixtures on one or all carbs.

If you're thinking of selling that seat, drop me a PM.

[rphillips]

A V&H pipe won't make that much difference. I think there may be something, other than jetting causing this problem. A barn find, could the spark advancer be stuck & not advancing the timing as the rpm. go up? I don't know, but I'd wait for other ideas from folks that do this all the time, before going into the carbs just yet. Great looking bike, I bought one new in "80" even that same color, great bike, but back then I needed more speed & traded for a GS1100E. The orig. seats, on them things, were really good, I think as good as most any OEM seat I've ridden. Welcome, Congrats, good luck, & thanks for the memories.

[rphillips]

Also, that looks like a V&H "Sidewinder" pipe, it will drag very easy on right hand turns, be careful.

[Joshgs1000g]

Appreciate the complements, ill be willing to sell the seat in the next couple months. Its not for me, I have to agree it doesnt flow the bike very well. However that seat is in absolutely perfect shape...
Ill have to study up on the dyna Ignition to see how it works, it would actually makes sense that the timing is not advancing in the higher rpm range, Ill look into it, and hold off on messing with the jets.

[salty_monk]

IMGP1951D.jpgIt should have a mechanical advancer on it unless it's the dyna 2000 kit. Very easy to check. Take the cover off and twist it & check it springs back freely.

You can also put a strobe on it.

Who rebuilt the carbs? Did they replace all the O rings? Have you replaced the O rings on the intake boots & checked the clamps have some tension in them? Have you checked the same thing on the other side? Both sides go hard and don't seal so well. You could also check that there is a filter in the air box (if so is it a K&N?) and then check that the airbox sides are sealing (the foam goes bad, use door foam peel n stick) and the seal between filter cage & airbox.

Your idea of 125 is probably right if the filter is a K&N, you probably only need to go up five with a pipe. That pipe won't be doing you any favours (it's a drag race pipe) does it have a baffle in it? I'd switch to a Delkovic if you want a 4:1 at reasonable cost.

Have you checked the tank breather in the cap is free and made sure the petcock is flowing properly?

Are the plug wires in good condition? Sometimes if they are cracked you can lose some of the spark to a short on the head (run it in the dark, you'll see the sparks as you wiggle the wires around). New plugs?

Lastly - have you checked the valves are in spec?

I had that same bike. Ran it with a V&H 4:1 that wasn't the sidewinder. Also ran it with both an airbox & K&N and Pods at one point. With the airbox on I believe I used the 122.5 jets and raised the needle a bit, wound the pilots out. Ran great. I live at sea level.

[salty_monk]

IMG_0733.jpg

Dyna S3 twist the middle bit

[Rijko]

[ATTACH=CONFIG]61153[/ATTACH]

Dyna S3 twist the middle bit

Could you elaborate on that a bit, please ?
Do they twist the rotor part causing timing to go off ?