Craigslist Project Bike: Tear Down and Carb Cleaning

Hell For Leather, How To -



Problem solved, turning the air screws a half turn made a tremendous difference. Hot or cold, under load or at idle, the bike had awesome throttle response and great pull.


At this point all that remains is some fine tuning, as under hard load from around 3,000 rpm to 4,000 rpm the Suzuki falls on it’s face, but quickly recovers. Some of our old-timer mechanic friends chimed in and they believed this might be an issue we have to live with as our Suzuki has one of the first electronic ignition. It’s hard to dial in this ignition as that’s the point the timing advances. We may try to re-jet the bike and play with timing to get it perfect, but for now, we’re satisfied.

We still had electrical issues as the headlight would cut out occasionally and the turn signals don’t work. Those issues will fix themselves as we plan on rewiring the bike anyway. Now that the bike was running great, braked and steered properly, we’re able to start the fun part – tear down.


We also did a compression test using an auto-parts rental tool to make sure we had good compression on all four cylinders. It’s tight!

Tear Down
We took our time, took notes and had plenty of boxes, sandwich bags and markers. Luckily, the main harness and front harness are plugged into each other with specific plugs that you can’t mess up when reinstalling. For the rest of the pieces we traced wires back to their origins, taking video notes on phones and leaving marked tape on wires.

The engine required the removal of six mounting plates and a couple bolts. We laid the entire bike over onto our Craftsman bike stand and then lifted the frame out from around the engine. Now, we’ve begun prepping the frame for paint, removing any unnecessary brackets and cleaning up sloppy factory welds.

The engine will receive spray-bomb, high-temp engine paint, but needs a heavy cleaning. We covered the intake and exhaust ports and scrubbed the engine with Home Depot pipe-cleaner wire brushes and Purple Power cleaner. We used our Harbor Freight grinding wheel with a cheap wire brush to tackle any area it would reach. We found some smaller brass brushes designed to work with electric screw drivers at the swap meet that we will also use before painting. The better the prep, the better the final paint.


Next Installment
We picked up a new front end off of a Suzuki RM250 with inverted forks for cheap off of Craigslist. We also found a mono-shock swing arm from a dirt bike along with a Triumph seat and a CB750 tank that needs restoration. In our next installment we’ll show how to restore a gas tank and properly space a swing arm. The new pieces are an odd-ball combination, but we have a few ideas in mind that will make for a cool bike.

  • Innis O’Rourke

    Glad you guys went to check out Gsresources. you cant go wrong there. I’m looking forward to part 3

  • Jesse

    Better suspension and brakes, wrapped around a characterful classic engine? Now I’m intrigued.

    • Jesse Kiser

      wait… brakes?

      • Jesse

        I’ve got an 83 GS450 in my barn. Any brake upgrade is better. :)

  • Lee Scuppers

    Enjoying this a lot. Will stay tuned.

  • Dotcuebed

    Article needs more pictures! And would it kill ya to post some video of the bike problems before you fix them? Context is everything.

    • Jesse Kiser

      I have more photos of the carbs and video of it running strong, but no video of it running poorly. Sorry about that. We will have a ton of photos for the next installment.

      • Dotcuebed

        Cool! Can’t wait to see a good build in progress.

  • Mister X

    Am I seeing duct tape velocity stacks in the lead photo, amazing.

  • CaptainPlatypus

    So glad to hear that I’m not the only one who makes about five mistakes a minute working on bikes.

  • robert stone

    how about an ’82 1100 maxim? just picked one up, and am in process of getting it going [been sitting for 6 years]. Am interested in carb/exhaust upgrades.. I tried SIGMA JETS on a 650, and had nothing but headaches. After 13 removal/part swaps it still ain’t right, and don’t want to go through THAT again

  • Armando Domingos

    Ha! Just saw my name in this… Thanks guys!

  • MrBill

    Okay, just saw this rebuild article. And right now I’m screaming at you guys. You started off wrong here. First thing you do before anything is check the valve adjustment on these bikes, you just DO. Then you can do your compression checks and you can tear into the carbs, I would HIGHLY recommend going back to the stock air box. CV carbs regardless how good you are at mechanics, just work better with the stock air box. If you go to a pipe and use a K&N stock style replacement air filter, tuning the carbs is sooooo much easier. One thing you need to do when rebuilding these carbs is get a new set of o-rings for it. NOT THE CARB REBUILD KITS. You can get the complete o-ring set from Robert Barr has spent the time to assemble these kits. Only gaskets you may need are the fuel bowl gaskets, they can be had at dealers. AND we at GSR recommend using OEM gaskets and maybe just maybe a new set of fuel needles and seats.. Look at the CV tutorial listed at GSR and follow it just like it is, NO short cuts. As for the carb boots, get new ones, believe me it is worth it, while at it get the OEM clamps, nothing works better.

    Now the electrical system, here is what you do. Inspect, clean, replace any and all corroded/burnt connections. Check the fuse box, check the connections inside, if it ain’t tight then replace. Here is the biggie, Stator and R/R unit. These bikes use a shunt type RR unit which is pretty much junk. 90% of us on GSR have switch to a SERIES type RR like the Compufire and or the Polaris-SH-775. Why? go to GSR website and read all about it. Then you’ll know why. By cleaning up the electrics, new stator, Series RR and a new AGM battery or something better then the ole wet plate acid batteries, you can pretty much clean up 99.8% of the electric woes associated with the GS series bikes. Just remember, this is what we say on GSR, you just got a 30+ year old bike that needs 20 years of maintenance. I know the 80-81 GS750Es inside and out. Just a last thought, you have the (shiver) L model you guys are working on. Not a very popular bike to most GSers. Though some like it…don’t know why lol.