I put my bike in the shop to get it back cost of $352. and running worse.I originally had popping on deceleration.They put new plugs in and adjusted the fuel air mixture screw. Today I put in a K&N air cleaner and cleaned the carb. Today I also put carb. 6 signma jet kit in too.Well I looked to make sure they replaced the plugs to find out that #1 and #2 was new condition no evidence of it firing. In cylinder.#3 and #4 were black.I took all out and spark test each wire got a blue spark on all four. It is a 1998 CBR900rr~~ANY HELP WOULD BE APPRECIATED !!

 

Before you tinker on this any further, you might want to brush up on some reading. Have a look at this link.https://cbrforum.com/forum/showthrea...ht=carb+tuning
If all 4 wires have a spark and seem to be a very strong spark then fuel would be a strong culprit. Just be sure all carbs are working in unison and properly synchronized.
If that shop released the bike running in an even worse condition and charged you for it, be sure not to do anymore business with them.

 

I will never do business with them again( American Warhorse)!!But thank you for the carb cleaning tips link. That was very useful. I already went through the carb. this morning and I used 4 cans of cleaner and compressed air.The carbs were not that bad,but the air/fuel mixture screw had a little carbon on the tip.Which the shop should of cleaned instead of just adjusting.Before I put the tank back on though I need to find out why the 2 cylinders are not operating

 

Not to sound like an a$$ or anything, but sounds like you threw too much at it at one time. If it was running like crap, shouldn't have installed that filter or jet kit. First gotta get it up and running good before doing any more mods. Make sure 1,2 are firing by spraying some water on head pipes after it's been running a couple minutes. If pipes on 1,2 sizzle, they are firing.
Where is everything set on the carbs? (what size mains, how many turns out on fuel screws, where is clip on needles?). Does it have full aftermarket exhaust? What part of the country are you? Tuning carbs is delicate work. The tiniest of changes can have big impact on how it runs.

 

I ordered the carb. kit and filter before I knew the 2 cylinders were not working.The region is Scranton PA.The stock main jets are 120.Today I put a 125 in the outside 2 and a 127.5 in the inside 2.I turned the air/fuel mixture 2 turns out.The needles have 2 washers seeing they don't have the e-clip.The jet kit suggested all of that.I had cleaned the old plugs about a month ago before it went to the shop.They were not that bad and they all were the same light brown,therefore I had not expected to find the 2 cylinders not working.I have a bolt on Yoshimura- RS3 muffler I put on last month too.The compression is 185 psi on #1,2,4 and 180 psi on#3

 

What year is it? If it's an older model with fuel pump...(just for ****z n giggles) unplug connector going to fuel pump relay and use jumper wire to connect black wire with blue/black wire going to pump (not 100% sure on the blue/black color, don't have a manual with me at work.). I've worked on a 900 doing similiar thing and turned out relay was going bad and caused misfire to plugs. It's a long shot but worth a try. Internet troubleshooting is far from being an exact science. It's alot easier with bike sitting in front of you LOL.

 

1998 cbr900rr

 

First get it warm and try the spraying water on header pipes. (Don't try to touch them quickly. No matter how fast I've tried that I always ended up with scorched fingertips LOL)

 

I put it all back together tonight.I noticed the spark plug wires were on the wrong spark plugs(that the shop that charged me all that money had done).And it sounds a lot stronger.I will test ride tomorrow.I borrowed my neighbors heat gun to check the exhaust.The #1 and#4 were in range of 400+ degrees while #3 and #4 were in range of low 300 degrees.I don't know maybe I have to tweak the air/fuel mixture screw on those carbs.I will ride for about 5 miles tomorrow then take the plugs out to check them I cleaned them real good.So combination of cleaning carbs. and putting spark plug wires where they belong might of solved the problem.

 

Good grief!! Yeah, that'd definitely do it LOL I think I would avoid that shop from now on. A 2 coil ignition system is about as simple as you're going to get. If you get plug wires mixed up, you need to stay the heck away from motorcycles...period. Hopefully plugs will all look the same after your test ride. If they all have light brown/cream color, you're good to go. Install the filter and then do another plug check. If they still have that color and bike pulls cleanly cracking the throttle at around 4K rpm's, I wouldn't even fool with jet kit. You won't see any gains from it. If plugs are all clean looking (like they were brand new) then install the kit and tune from there.