Hey All, my buddy just picked up a 99' 900 RR. Got a couple of questions, im carb challenged.
1. The tach is stuck & revs backwards???
2. The bike stalls when u twist the throttle more than a quarter of a turn, But if you ring the throttle full, it intermitantly revs all the way up with a delay and sounds funky like its choking????
3. where do i start to fix this bad boy. it says on the odo. that it has about 4000+ miles on it. Where should i start to tinker to get my buddys new ride running smoothly. I tried to take it up the street and the bike stalled immediatley, it has fresh gas & new plugs, ANY ADVISE AT ALL WOULD BE EXTREMELY APPRECIATED. Thanks

 

The tach running in reverse is a new one, can't help you there but as far as the hesitation, it's deffinately dirty carbs and possibly impropper jetting. Start with a thorough carb cleaning and reinstall. You'll deffinately see improvement but if it's still not quite up to par, you may need to play with the jets a bit.

If you figure out the problem with the tach, please post it here.... It has me curious..

 

Run 89 Octane gas (the additives will clean up tarnish) for awhile in it. No matter what you will probably have to remove them and clean them up......I've heard that SeaFoam works but a GOOD cleaning is still in order.

The tach? WOW.......that seems odd. I can not say I've heard of that. Could the leads be hooked up backwards or shorting somewhere?
That would be my guess.
Take good pictures of the carbs as you work on them and do one part at a time so you dont get confused. There are lots of small parts in there. LOL.

 

your carburetors needs to be synchronized again dude........... this not going to be an easy job anyway.

 

You are going to have to sit down and have a few coffee's on this job..

A while back when money was very tight I had a 1980 Suzuki GS1000E. It was a nice bike and would often stutter and spit and run badly. One day I was out and met the original owner. He had had the bike for something like 20years and said he put an eggcup of Marvel Mystery Oil in the tank about once a month, and never had any carb issues.. I went and bought some of the stuff and put a swig in the tank. In minutes of use the thing sorted itself out and ran cleanly. Everything went south when I redid the heads and cams for a bit more power..but that is another story.

A couple of weeks later a buddy did the syncronisation (he wouldnt before because the carbs needed a "rebuild") and I rode the thing for a couple of years with no carb issues..

My Yamaha had similar symptoms and the Marvel oil didnt help one bit.. It had been sitting a whilie and I took off the rack of carbs and was amazed how clean and right everything was. After a few coffees and a lot of head scratching the fault eventually was traced to really crappy plug caps. Who would have thought - hours of messing around for an hours worth of work..

God only knows why your tacho is running backwards.. I would start there and see if unhooking the wiring for that liberates the motor..

CJ

 

Someone Proly switch wires on tack, or it shorted.

 

I recommend SEAFOAM to clean your carbs. It did a miracle on mine. Its about $7 for a pint and you can pick it up at most car care stores. Follow the directions and see the amazing results for yourself!!

 

Thanks Guys, I Made a deal with my buddy, So im doing the work on his bike at my house. TODAY IS THE DAY im starting to bring her back to life. Im about to go pick up some seafoam, im gonna pull plugs check for spark, check the airbox, clean the carbs, check the fuel lines, inspect the tach( i let you know when i figure that one out)) Once again,Thanks for the heads up, I dont ever deal with carbed bikes since mine is fuel injected. I'll post back soon when i get some results ( hopefully). BTW What is the best site for a free oem manual download, im having trouble with the post on this site that have links to downloads. i need a 99 900RR manual. THe MOM Is the best thing to have during an operation ( Motorcycle. Owners. Manual)

 

Heres where im at so far.....Got the bike running, took it out, But it almost feels like not all cylinders are firing. I seafoamed the fuel tank. Pulled the tank off found some cut hoses, replaced them. the air box wasnt seated properly on the stacks. fixed and cleaned the air filter. checked hoses for kinks/ damage/ I pull the combination assembly out and opened it up, I put the tach needle back on the left side of the little stopper, Connection was fine, closed it up , started the bike it didnt stall and didnt have delayed response. BUT the Tach is still going backwards. I also pulled off the muffler & checked for clogs, it was fine.

Long story short, the bike is running again, just lacks all *****. I pulled out the spark plugs, properly gapped em. BUT i noticed the plugs were colored REALLY light, almost White. THis either means im runnin to lean, or I got ignition issues. What should i do next ??ANYBODY FEEL FREE TO CHIME IN HERE. Im getting spark at the plugs, IS it possible that the ICM is done, or the Ign. Coils are weakened,??? I checked a ton of connections on the harness and everything seems to be fine. BTW when i pulled the air cleaner housing apart, There was Gas in it, a little puddle of it off to the side inside the box..WTF. Help Need SOME CBR MOJO WISDOM. Thanks Guys[:@]

 

i had a 1997 cbr 900rr and it ran like a v twin then i noticed the plug wires were on wrong so definately check that. when i first bought my bike the bike shot out flames turns out the vaccum line from the gas tank wasnt connected.the jetswere real dirty so i cleaned those and got the firing order right and the bike ran perfect for the whole summer make sure you adjust the idle screws