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Discussion Starter · #1 ·
Hi, new to this forum, hopefully will be here to stay (if I dont' get fed up of my bike first, but I have lots of patience)

I bought a raunchy RF900, the previous owner tried to mod it and I ended up getting a non working bike (cheap though!). The engine looks to be BONE STOCK, and has less than 10000 miles on it.

The engine turns over and starts but the carbs have a major problem. It seems to die beyond quarter throttle, even that 1/4 throttle doesn't sit right the engine constantly tries to die. If I give it gas it'll try (although very hard and terrible response) to muscle it out to about 4000RPM and beyond that the engine just dies.

I did read the manual, the repair diagrams, I cannot find anything wrong for the life of me. Has anyone had this problem before? I have 2 sets of carbs and they both do the same thing.

Input will be greatly appreciated from anyone that has experience with these bikes. I've only worked on V-Twins with single carbs so I'm a complete newb at this.

Thanks!
RJ
 

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Have you pulled the float bowls on both sets of carbs?

If all the jets are clear, it could be the fuel pump (or kinked fuel line), not keeping the float bowls full.
 

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Discussion Starter · #3 · (Edited)
OK, thanks. I used some carb clean without much luck. It seems to just die past quarter throttle.

If I open the bottom of the carb, would I be able to get to the float bowls? I checked the fuel pump, and it's pumping until the carb fills up, then it stops pumping. Not sure how that mechanism works but it seems to be a low pressure line that's only engaged until the floats filled.
 

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Discussion Starter · #4 ·
Is there nobody out there that can deduce a few possible issues from the symptoms given?

If not, what are some possible throttle bodies that may fit on the bike? I'm actually quite tempted to just megasquirt this sucker into working.
 

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Sorry,
I've been out of town.

Four screws on the botoom and you get into the float bowls.

You can then check the floats and seats and see if that is the problem.

Have you already checked to see that the slides open all the way and are smooth.

I only found one place that has F.I. you could install. If i remember correctly it was like $3000.00
Would be nice, but the the FI system would cost you more than what a running RF900 is worth anyway. But if you love the bike and what to keep it going, it would definatly fix your problem.
 

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Discussion Starter · #6 ·
Thanks for the reply, I actually just got another set of carbs, and the bike is acting the exact same way. So it must have something to do with my hook-up. I guess I've never understood carbs, I know they don't run correctly in different altitudes but I didn't know it was this twitchy.

I just finished converting one set of carbies into an ITB system :cool: so I'm just going to get some used Civic injectors and rig up a quick open loop EFI system while I try to figure out this carbureted mess Suzuki made :fight2:
 

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Okay, when your bike dies at 1/4 throttle, this usually means you not getting enough gas. Which tells me that it could be a few things. I am not real familuar with the RF900, but I am with CV carbs. Based on not enough information really as far as year, where the other carbs came from and how long the bike (carbs) has set and if they were left with fuel in them, here are some possibilities:

1. The throttle slides are sticking and not sliding freely
2. ports/jets in the carbs are blocked or partially blocked not allowing enough air, fuel or both.
3. vacuum leak in the carb that affects the throttle slides.

I would recommend taking the original carb bank and doing a complete tear down and boil out cleaning with a good carb cleaner like Barrymans B12 Carb cleaner. Estimated time should be about 2.5 hours plus to do it right. Replace all o-rings, gaskets, needle valve and seat. You might also want to replace the rubber part of the throttle slides, these do go bad.

Make sure of all settings, floats, air/fuel screws, etc.

If you can not able to or are uncomfortable doing the work, I can do the work for you. If you have any questions, feel free to call or email me. My info is in my signature.
 

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Discussion Starter · #8 ·
Hi, thanks for the reply.

I'm not really sure what's going on and why it's reacting this way as 2 sets of carbs did the same thing. I did tear one set down, give it a ***** and span, new o-rings, cleaned out the jets with air. It just did the same again. I'm almost entirely sure it's getting way too much air, but don't know from where or how my vacuum hook ups could be wrong.

On the 4 set CV carbs, is it very important that the carbs should be synched? I wouldn't mind if it ran crappy, i can probably tune it by feel from there to get it running decently enough.

It just doesn't even give the hint that it will even idle properly muchless run.
 

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Hope This Helps!!

I have a 94 Suzuki RF900R and have had it for over a year!!

One time when I first replaced the sparkplugs I did look to see where all the plugs went back to and the wires wern't marked either and when I would start my bike it wouldn't run right. It would start but woundn't run right because I had two wires right and two crossed.

Try checking that out if your wires arn't marked 1,2,3,4

Also when u take your bowls off you will see the floats and the floats are on a arm that is held inplace with a very small screw, when you take that screw out, and than pull the arm out which has the float on it there is a very small filter screen on that arm that you can't see til you pull the arm out!!

If that screen is clauged up at all on any of the carbs it won't allow you bike to run right either, it could even cause your bike to be fauling out.

Check these things and see if it helps you!!
 

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Same thing with my rf900

Hi, new to this forum, hopefully will be here to stay (if I dont' get fed up of my bike first, but I have lots of patience)

I bought a raunchy RF900, the previous owner tried to mod it and I ended up getting a non working bike (cheap though!). The engine looks to be BONE STOCK, and has less than 10000 miles on it.

The engine turns over and starts but the carbs have a major problem. It seems to die beyond quarter throttle, even that 1/4 throttle doesn't sit right the engine constantly tries to die. If I give it gas it'll try (although very hard and terrible response) to muscle it out to about 4000RPM and beyond that the engine just dies.

I did read the manual, the repair diagrams, I cannot find anything wrong for the life of me. Has anyone had this problem before? I have 2 sets of carbs and they both do the same thing.

Input will be greatly appreciated from anyone that has experience with these bikes. I've only worked on V-Twins with single carbs so I'm a complete newb at this.

Thanks!
RJ
Hey It sounds like the same thing that happened to me. I took mine in after i got tired of working on it. The guy working on it for ten mins finds that the fuelpump went out and when the tank is full it runs but as the tank gots low it dies off at around 4000 and dies altogether at a 1/4 tank. So id check that first and you should be able to hear it running if not thats it. I also had a vacume line off one of my carbs. Good luck. Don [email protected]
 

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Hey It sounds like the same thing that happened to me. I took mine in after i got tired of working on it. The guy working on it for ten mins finds that the fuelpump went out and when the tank is full it runs but as the tank gots low it dies off at around 4000 and dies altogether at a 1/4 tank. So id check that first and you should be able to hear it running if not thats it. I also had a vacume line off one of my carbs. Good luck. Don [email protected]
 

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I have a 96 RF900 thats having some kind of issue I'm assuming with the carb. It's idling high and it does fine up to about 65 mph. I still have more than half the throttle but when I increase the throttle past that point it starts sputtering and losing speed. I'm just learning bikes and am stumped. Any ideas or advice would be welcomed
Okay, when your bike dies at 1/4 throttle, this usually means you not getting enough gas. Which tells me that it could be a few things. I am not real familuar with the RF900, but I am with CV carbs. Based on not enough information really as far as year, where the other carbs came from and how long the bike (carbs) has set and if they were left with fuel in them, here are some possibilities:

1. The throttle slides are sticking and not sliding freely
2. ports/jets in the carbs are blocked or partially blocked not allowing enough air, fuel or both.
3. vacuum leak in the carb that affects the throttle slides.

I would recommend taking the original carb bank and doing a complete tear down and boil out cleaning with a good carb cleaner like Barrymans B12 Carb cleaner. Estimated time should be about 2.5 hours plus to do it right. Replace all o-rings, gaskets, needle valve and seat. You might also want to replace the rubber part of the throttle slides, these do go bad.

Make sure of all settings, floats, air/fuel screws, etc.

If you can not able to or are uncomfortable doing the work, I can do the work for you. If you have any questions, feel free to call or email me. My info is in my signature.
I have a 96 rf900 it's having issues I'm assuming with the carburetor. It does fine all the way up to about 65 mph and when I increase speed at that point if sputters and starts losing his feet. I'm just now learning bikes this is my first one any ideas or advice would be greatly appreciated. Feel free to email me at [email protected]
 

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Welcome to the forum.

The discussion you replied to is about 10 years old.
The original participants likely won't see it.

Is this bike stock or does it have modifications to the pipes and intake ?
Does the choke seem to work right ? It might be stuck partly closed.
Also those symptoms sometimes indicate a vacuum leak around the intake.

The first thing I would suggest is draining out all of the old gas that you can and putting fresh gas with a healthy dose of Berrymans B12 Chemtool. NO, Seafoam won't do.
 
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