Sounds like carbs may not be delivering fuel correctly to start and run.

Things to check on carbs:
• Idle jet clean? Clean and blow out with compressed air. It's a pin hole, so make sure it's clean and you can see through it.
• Remove idle mix screw as well as idle jet. Crap can get caught behind it.
• Idle circuit now clean?
• Remove enrichment plunger for each carb and clean out choke circuit
• Do all four enrichment plungers move when choke pulled?
• Check float level (floats might be non-adjustable) Low float level means lean idle mix setting
• Check idle mix screw setting and return to OEM (3 turns out from lightly seated)
• Check fuel flow from tank into a cup with petcock "on". Is it flowing or trickling?

Is the bike jetted? If so, are the needle clips in the recommended slots? Can you return the carbs to stock needles, main jet and go from there? It's often harder to diagnose carb issues with aftermarket parts in there that aren't working well for your setup. I say this because it might be hard to start due to being REALLY rich, even at idle. Adding the choke might make it impossible to start.

Good luck!
(BTW: Owned a '93 RR from 1993-2012)

 

Got her running boys, here's a clip, lemme know if you hear anything funny!

Thanks for all the help everyone, couldn't of done it without y'all!

I'll continue to post any updates

 

Good job John! Sound like it's missing on one cylinder in your video. A quick way to determine which cylinder isn't working is to pull each plug wire while it's running. When I had my 900RR, I was able to put a short piece of wood under the tank in the front, across the frame spars, and hold the tank up enough to reach the plug leads. Another way is to wet an old rag and within about 30 seconds of starting it up, touching each header pipe. The cold/cooler one is the miss-firing cylinder. Then it's a matter of verifying spark to that one. If good spark, it's likely a carb issue or an air leak around the carb boot.

 

Hey Brian, thanks for the input!

I was told in a previous post by my bud Tony that I should check the cylinders to make sure they're firing. I donno how you guys can tell just by hearing the bike in a low quality video, but good on ya!

So now that I can get the bike running consistently I am finally able to check which cylinders are firing, and I did. Seems like two of the 4 cylinders are firing; only two exhaust pipes were hot. Too a look at my carb while she was running, the carbs on the dead cylinders weren't sucking air and the part you can see when looking down the carb air intake weren't moving(part shown in the attached picture). That's as deep as I've gotten into the carb so far.

I know for a fact I have a good park at all plugs. I just replaced the plugs and checked them all for spark.

Again thanks for the input guys.

 

John, that's good you narrowed down the cylinders with issues. Unless you're suspecting an issue with cylinder/piston damage from extended storage and rust (stored outside for many years), I would proceed with a carb diagnosis as the main problem. If you wanted to pick up a compression tester to confirm the motor is solid and without issues, you'd need to get one of these: https://www.amazon.com/Actron-CP7827.../dp/B0006V2BRS

Knowing that two of the carbs don't seem to be functioning properly, I'd pull the carb rack and disassemble the two you marked. The slides (where you put the red x in the pic) are vacuum operated, retracting up when the engine picks up revs. Remove the slide tops and check each slide diaphram for holes or tears. Also check the blow out the vacuum port under the diaphram in the carb body that feeds that area with vacuum. Lastly, check that the slide moves freely up and down in the carb. Any dragging will cause them to stick or react slowly to RPM changes, which will cause a lean condition at partial-throttle. If the two problem carbs check out with no tears/holes, and move freely, I would pull the bowls from each, and with compressed air and carb cleaner, thoroughly clean each port and passage. Sounds like there could still be some old fuel varnish or debris blocking a fuel passage or air bleed that's needed for the carb to pull fuel from the bowl through the idle jet.

Keep up the good work. You're getting there!

 

Hey Brian.

So I pulled off my carbs today and managed to disassemble one of the problem carbs. I did I full disassembly and cleaned everything metal with carb cleaner. The pictures attached are post cleaning. It appears everything is in order, to my eye, please let me know if you notice anything. Also, the slow jet is only supposed to have a tiny hole in it right? smaller then that of the head of a pin? because thats what I have after dunking it in carb cleaner and blowing through it.

One carb to go and hopefully I'll get her running properly! might just clean them all though, since I have them out.

Oh yeah, and when I have her running she idles quite high, around 3000rpm, obviously not normal, is this due to the loss of the two cylinders? Logic would lead me to believe she would idle slower because the two cylinders are doing more work...

Anyway, Thanks! and I'll post soon

 

Happy 4th John!

Your carb pics after cleaning look great. Yes, the idle jet is just a pin hole. Amazing that the tiny amount of fuel drawn through it at idle as enough to run the bike! If you hadn't, definitely remove the idle mix screw and clean out that circuit with cleaner and compressed air before reassembly. If not, crap will get forced into the passage and stick behind the needle of the mixture screw. Once that's done, complete the same R&R on the other three carbs and you should have a fully serviced set ready for use. The last thing I would check is air leaks around the carb intake boots. As they age, they get hard and after a few reinstalls sometimes don't seal around the head flange or carb 100%, even with a tightened band clamp. Easiest way to tell if you have a leak on any is to hit each with a shot of carb cleaner from all sides and watch to see if the motor gains RPM. They're not too expensive, $10 each or so. If you find one bad one, it's cheap insurance to buy four new ones and sleep easier. Also, do the float valve plungers on the end move freely and spring back? While restoring my current bike ('91 CBR1000F), which sat for many years without use, fuel varnish choked and killed two of them.

The high idle speed could be caused by one or several air leaks. If so, the new intake boots should resolve that and return your idle speed to normal. If no leaks are found, it can easily be adjusted by the idle speed adjuster under the carb assembly.

Brian

 

I have kinda the same issue but mine wont stay running at iddle unless i hold the throttle open a little or the choke.