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Discussion Starter · #1 ·
Can\'t rev past 9000RPM bad sputter help please.

I have a 98 GSX-R 750 that has 15 000 km (around 8000 miles) with a Hindle full system, K&N, TRE eleminator, +1 sproket in the back and the rest is stock. This weekend I was checking the bike over and I had a little leak comming from the tank so no biggie I just replace the stock gasket and no more leaks but now when I ride the bike, I can't get it to rev past 9000rpm. It feels fine from nothing to 8000-9000 rpm then it start's to sputter real bad and chercks and does not want to rev past about 9000rpm. I was thinking it was maybe a spark plug so I got some new ones and gapped them to speck and checked if they where firing and everything checks out. The only thing I did wrong when I was changing the gas tank gasket (the one between the pump and the tank) was that I forgot to install that little metal plate that goes between the pump and the tank could that be the problem (I'm thinking maybe it grounds the pump or something) but I didn't touch anything else. I really need your help as I really don't know what to look at next and I don't feel like taking it to the stupid dealer for them to charge me way to much to not even find the problem. Thanks for your help and no it didn't do that before I touched the tank and yes I already checked the lines to the gas tank and they look fine. Again thanks for your help you guys are the best.

[ 09-26-2002, 03:22 AM: Message edited by: Zomby ]
 

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Re: Can\'t rev past 9000RPM bad sputter help please.

The only thing I did wrong when I was changing the gas tank gasket (the one between the pump and the tank) was that I forgot to install that little metal plate that goes between the pump and the tank could that be the problem (I'm thinking maybe it grounds the pump or something) but I didn't touch anything else.
<font size="2" face="Verdana, Arial">I used to have extra parts too when I worked on things.

I can't help with your problem but I would suggest putting the plate back in and see what happens
 

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Re: Can\'t rev past 9000RPM bad sputter help please.

Mine did the same thing a few months ago in May. So I took it to the shop and they told me that the cam timing had jumped about two teeth causing the problem. After the was cams were adjusted, the problem still went on. Come to find out the spring on the kick stand was stretched, so when the bike hit about 8-9K rpm the kickstand would fall slightly from the vibrations in the bike. This may not be your problem, but sometimes the simple things is the answer. Just put the bike on the rear bike stand and run it to about 9,000 rpm while looking at the kickstand to see if it falls. BE CAREFUL WHILE BIKE IS RUNNING ON REAR STAND!!!
 

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Re: Can\'t rev past 9000RPM bad sputter help please.

Sounds like cam timing to me...

Also, does it only have the problem in gear?? Can you rev up with no load?

John
 

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Discussion Starter · #5 ·
Re: Can\'t rev past 9000RPM bad sputter help please.

No it does it while in neutral to. You see what's funny about this is before I touched the gas tank, the bike was fine. Take off the gas tank to change the gasket and the first time I take it out, come to the corner of my street, take off in first and at 7000 rpm I give it some gas to pull a nice wheelie and it started jerking on me. Would the cam timing jump just by starting the bike up to move it around in the garage and to check for fuel leaks after I replaced the gasket? When I reinstalled the gasket and pump, I forgot to install that little metal plate that goes in between could that be causing my problem? Like I said the bike runs just fine from 1000 rpm to 7500 - 9000 rpm, after that, it just sputters and jerks (to bad my girlfriend doesn't have that problem hahaha). GSX-R Freak, can you tell me or show me a link that would explain how to check the cam timing??? I work on cars for a living so I know what I'm doing when it comes to mechanics, just not on bikes
so please help me out, I really don't want to take it to those idiots at the dealer.
 

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Re: Can\'t rev past 9000RPM bad sputter help please.

Well yes the chain can jump on its own... Normaly when the motor is shut off it would jump if the CCT is bad.

To check, pull the right side plastic off, There is a case cover with two silver caps on it... Take them off. In the larger of the two there is a 14mm bolt and you need to turn that clockwise till you see the TDC mark in the other whole.. There is a grove in the smaller whole to like up the TDC mark with. Once you are at TDC then you can remove the seat and lift the tank, Remove the air box and then take the TBs and move them down as far as you can. Remove the valve cover. You will need a mirror to check the cams. but if everything is correct, on the ex cam the number 1 and 3 should be level with the side of the head, and the arrow on the #2 should point to a pin on the chain. that is pin 1 and you need to count 15 pins back and that should be were the #3 arrow point from the IN cam.

If they dont line up then you have a problem. Remember that if the motor is on the ex stroke then you will be 180* out of time.. so turn the motor over to TDC again..


John
 

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Re: Can\'t rev past 9000RPM bad sputter help please.

Dude, start with the simplest fix. Put that metal plate back in and see if that was it??? If not, then you can start lookin elsewhere, but if it ran fine right before you took parts off, chances are its in that area... my.02cents.
 

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Discussion Starter · #8 ·
Re: Can\'t rev past 9000RPM bad sputter help please.

Thanks guys.

GSXRFREAK, I'm going to look at the timing this afternoon and I'll let you know.

outcold, the first thing I'll do is put that plate back on before I do anything so don't worry and I'm thinking the same thing, if it was fine before I played with the tank, chances are the problem is comming from that.

I'll let you know if I find anything.
 

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Re: Can\'t rev past 9000RPM bad sputter help please.

i havethe diagrams for the timing sprockets/chain if you want me to post a hi-res scan of em for ya...

email me if you neeed any info form the OEM manual

esemes
 

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Discussion Starter · #10 ·
Re: Can\'t rev past 9000RPM bad sputter help please.

Thanks for the offer eSeMeS1K2K2 but I went to my dealer and got them over there. Well bad news, the cam chain did jump on me and it jumped 2 or 3 teeths (not sure yet) but both the cams jumped the same amount of teeth wich I find very bizare. I'm starting to wonder if the guy that had the bike before me just didn't know what he was doing with it or maybe he thought that if he advanced the cams, he would get more power. So I checked the timing and both cams have exactly 15 pins apart but when I'm at top dead center, I can't get the 1 and 3 to line up on the exhaust cam so what should I do (GSXRFreak)??? Is it possible that both cams jumped 2 teeth (or 3, hard to tell right now) at the same time?
 

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Re: Can\'t rev past 9000RPM bad sputter help please.

Normaly one cam will jump and other will just go with it... Just retime the cams and see if she starts... It is a very common problem... If it will start up after that then I would get a Manual adjuster for it. Did the bike run when you got it? I think you said it did.. And if it did then the guy before you didnt do this.. it is the bad CCT.

Anyhow... You need to pull the cam caps, the torque for the cam cap bolts is 7ft lbs and the order to tighten them should be printed on the cam caps..


John
 

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Discussion Starter · #12 ·
Re: Can\'t rev past 9000RPM bad sputter help please.

Yes the bike was running when I got it and it still ran before I checked the cam timing so that's why I don't know if it was like this before. I rode it all summer with no problems and it was taken to red line on a daily bassis but it just started doing this a couple of days ago so maybe it is my cam timing. I'll put them back to stock and see if the bike runs good after that. If it does, I'll get a manual CCT. I'll let you know. You think that by jumping 2 teeth that a valve would have hit a piston? (I hope not!!!)
 

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Re: Can\'t rev past 9000RPM bad sputter help please.

It could but I have seen them jump like 4 teeth and not hit... So I dont know... It is hard to say...

You would know right a way if even one tooth off... Trust me... Also, it is very common of a problem, so it isnt you.. lol

John
 

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Discussion Starter · #14 ·
Re: Can\'t rev past 9000RPM bad sputter help please.

Well I'll let you know how the engine is when I get the call from the dealer. I'm getting it checked to make sure everything is fine and if not, well I'll come back to you for some more info and opinions. It was running fine when I took it to the dealer so I'm hoping the engine is fine.
 

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Discussion Starter · #15 ·
Re: Can\'t rev past 9000RPM bad sputter help please.

Well the dealer checked my timing and I did set it correctly so that's good (thanks GSXRFreak for the pointers) and everything is fine now. I'm going to do a compression test later so can anyone tell my how much psi I should get with it. Remember it's a 98 with 8000miles.
 

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Re: Can\'t rev past 9000RPM bad sputter help please.

Well you should worry more about them all being close to the same... i think the min spec on the bike is like 158psi or something like that.. but your bike will be in the area of like 130 ish...

John
 

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Discussion Starter · #17 ·
Re: Can\'t rev past 9000RPM bad sputter help please.

OK well checked the timing to make sure I didn't hit anything when my cct went bad and here's what I got: 1 at 160, 2 and 3 are at 165 and 4 is at 175 so that's pretty good right??? (please tell me it's fine
 

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Re: Can\'t rev past 9000RPM bad sputter help please.

DID you check the compression with it at WOT as you crank it? Also how many compression strokes did you let it make?

There is a BIG jump from 160 to 175..
But if you didnt count the same number of compression strokes that would be why.

If you did everything correct then you might have a problem with the #1 cyl... It is a bit lower then the rest.

John
 

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Discussion Starter · #19 ·
Re: Can\'t rev past 9000RPM bad sputter help please.

Well I think I let the others go on for a little longer so I checked them again last nigh and every thing is fine. There all between 168 and 175
and those where made with no throttle input. I think those numbers are kind of high though no??? I guess it would depend on how much compression cycles I let it go through right??? I let it go through 3 cycles (If I counted correctly, I was kinda drunk
(but don't worry I didn't ride the bike, just played around with it in the garage!!!)


[ 10-04-2002, 04:46 AM: Message edited by: Zomby ]
 

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Re: Can\'t rev past 9000RPM bad sputter help please.

Well you should check it at WOT and let it run 4 cycles. That is the standar for checking..


John
 
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