Mikuni Carb Teardown and Rebuild - GS550 Cafe Racer (Part 103)

[@shaunholbrook8575]

i bought some viton o rings, and cut the plastic/rubber to the second "bump" back to the inner metal. then slid two o rings on ,each side, perfect, no leakage

[@UrbanMonkTV]

Great tip! Thanks for watching and for sharing that here for the benefit of others who may read these comments.

[@johnbaird7925]

I found that ta fuel filter, simmular to the one shown in your post, restricted the gravity fed fuel to the catbs.

[@UrbanMonkTV]

Thanks for watching. I still have the one in the video on the bike and have not had problems with the engine showing any signs of fuel starvation. How did you observe the restriction you experienced?

[@bluehazeboy]

Top job, all the best for you & your family, I bet you were surprised how dirty the carbs were, considering how good you cleaned them previously

[@UrbanMonkTV]

Thank you. 🙏 One could take the position I didn't clean them well previously. 😄

[@bluehazeboy]

Urban Monk TV I too have a ultrasonic cleaner' & no matter how much you clean by hand, you couldn't match the ultrasonic cleaner,a great piece of garage kit,

[@UrbanMonkTV]

@@bluehazeboy Agreed, now that I've used it. Can't wait to use again.

[@romacthingstodo]

Hey. Your videos have been a massive help and encouraged me to try everything myself. Been a non mechanic. I also managed to fully rewire the bike. 77 GS550. last night completely tore carbs down with the help of your video and getting a lend of a sonic bath to clean them. Could you advise on the jets please. Going to run pods and a 4 into 1 exhaust. Was thinking 97.5 main and leave the other at 50. Close to sea level here in the north of uk. Summer max temp generally low 20s. Thanks in advance. Rob

[@UrbanMonkTV]

Sorry for late reply. KZbin doesn't do a good job of notifying me when comments are posted. I'm running 95s currently and I'm happy with them. I think your choice of 97.5 is a good one. It's certainly in the same ballpark with my choice. I'd be interested to know your thoughts after running them a while. Maybe I'd increase mine, though Mr. Kortan is running good with 95s right now. Hope this helps!

[@romacthingstodo]

Hey there just an update on the jets. I've had the 97.5s in a couple of months now and running well. Left the other jets standard at 50s but raised the needles by 1 notch. Little popping on decel but think this is more to do with the exhaust and I can live with it quite happily. 4 into 1 with a medium length can. Cheers

[@sawoski]

Greetings from finland! How many turns is original adjust for that air screw bottom of the carburetor?? Service manual don’t give help with that one, it only says ”do not disturb the screw shown in the photo” ..thanks allready

[@UrbanMonkTV]

I started at a couple turns out from seated but then adjusted each individually with Colortune. I have a video of that later in the series. Hello from Los Angeles!

[@liferider2089]

Hi Enjoy vids,got a gs550e that now has a 650 top end :) Do you know the paint code as I have damaged similar cream colour? Thanks either way.

[@UrbanMonkTV]

Thanks for watching! Just for clarity, are you asking me for the color I used on my cafe racer? The cream with the green stripes? I ask because it was not an original Suzuki color.

[@TheRealPhilipK]

Question... at 13:04 - you mentioned that the choke was all corroded. I also noticed that the choke cannot be removed unless you pulled all the carbs apart. Is it possible that "corrosion" is part of the Pine Sol dip from your previous video?

[@UrbanMonkTV]

Yes, I think that may have been the case. Once I took them apart and cleaned individually the action became smooth and the bike is running well now.

[@allisonsailsandcanvas]

"Don't force it there Randy" PTL

[@jacksonmehoff4963]

I need to replace the fuel inlet "T" and the connectors between carbs. Any help on how to get them off the mounting bar? Or where to get new pieces. 78 gs1000e. Doing 2 of them right now

[@UrbanMonkTV]

I'm sorry, I had responded to your question many days ago and now see that my response did not post for some reason. To get the three fuel rail parts out (T and 2 straight unions) you must take the carburetor bank apart (separate the 4 carbs). I have a video on how to do that. You can find new aftermarket replacements on eBay from this seller: www.ebay.com/itm/284272769290?hash=item422ffa390a:g:ocIAAOSwx6lafgvc . But In my case I was able to use my old ones with some Permatex 2A fuel resistance gasket sealer and it has been working for me. Be sure to check often for leaks if you go that route. Hope this helps. Thanks for watching.

[@SkyWasYellowSunWasBlue]

Great videos. Appreciate the detail! I picked up a gs750 1980 model and the starter button does nothing when I jump the starter the motor spins great with about 125psi per cylinder but it won't start! It has spark and fresh fuel bottle fed from an aux tank. Any suggestions on how to get it to start. Please and thank you!

[@UrbanMonkTV]

Are the plugs getting wet?

[@SkyWasYellowSunWasBlue]

@@UrbanMonkTV I haven't checked all of them but I know one of them was...

[@UrbanMonkTV]

@@SkyWasYellowSunWasBlue And, if you put a 1/2 teaspoon of oil in the cylinders, does the compression increase. Also, is the spark a good hot spark and timed well? These are hard starting cold engines and compression, fuel, spark and timing need to be working g reasonably well to get going. Once they warm up their easy peasy.

[@SkyWasYellowSunWasBlue]

@@UrbanMonkTV so I just checked them again and one of them shocked me pretty good in the process! When I had number 1 cylinder out it actually shot some questionable looking fluid out of the cylinder..like a rusty gassy smell fluid??

[@UrbanMonkTV]

@@SkyWasYellowSunWasBlue ok, So that tells me you could have clogged idle fuel circuits in one more carbs. Carbs may need cleaning. Of course nothing in my diagnosis is for sure given I'm observing from my armchair here, but at the end of the day, if an engine has proper timing, fuel, spark and compression, it has no choice but to run.

[@michaeldamico5174]

Is that a normal gap on the slider on the pod filter side? I’ve always thought for bench sync that light should just barely get through. My 78’ 550 bank has the same about 3-5mm gap on it without any idle/throttle cable attached and idle screw all the way out. Is there another way to lower them?

[@UrbanMonkTV]

Thanks for watching and for your question. I haven't touched those carbs in a few years so I'd have to revisit these myself to get an answer for you. What I can say is at rest, the sliders should not be held in place at idle by the cable position. The individual sliders themselves have adjustments for that idle position height. Hope that makes sense.

[@24jhs]

What brand and model of ultrasonic cleaner do you have in this video?

[@UrbanMonkTV]

Thanks for watching. Brand is generic. Model is 230HTD. I got mine from eBay. Works well for one carb at a time.

[@24jhs]

@@UrbanMonkTV Thanks so much.

[@jsturgess3456]

Did you check to see if the small pilot jet bottom holes were clear after cleaning? although I have cv carbs on my gs 550 this was the source of my carb problems, had to use a very thin wire to poke them through even after cleaning them several times!

[@UrbanMonkTV]

Yes. Yours absolutely right those need attention. 👍🙂

[@emmaperry2103]

I'm brand new to motorcycle maintenance and I've accidentally broken a piece in the carburetor. I'm so new to this that I don't even know what it's called, nor can I find the name in the manual. It's the only brass piece that isn't removed after you've taken all the removable pieces out of the bottom... it's a skinny brass tube with a few tiny holes in it. Is this replaceable or have a screwed myself? I hope you can figure out what piece I'm talking about! thanks

[@UrbanMonkTV]

Don't worry. No biggie. Sounds like you are describing the needle jet. Sometimes called an emulsion tube. You could find a used on eBay. I wouldn't be afraid of used as they don't wear out. Otherwise Jets-R-Us can sell you a new one. Call them for help finding the correct one. Good for you tackling this yourself! Edison made 1000 light bulbs that didn't work before he made one that did. Thanks for watching!

[@jerryking1434]

Midrange bog..doesnt want to accelerate ..or accelerates slowly if you can find the sweet spot

[@UrbanMonkTV]

Are all four cylinders firing? If so sounds like something is clogged in one of the carb circuits. Jets and emulsion tubes all clear?