FZR 2KR WONT REV OVER 10000 WHEN IN GEAR

Hi Guys,
Names Jake Im New to the forum here I have recently become a owner of a 1988 FZR 250 2KR its non exup not sure if it was before hand as it has a custom exhaust from the headers back. Anyway bike is running fine sounds great but im having a issue getting the revs up the bike will rev to redline while in neutral but once ridding its as if I am hitting a limiter at just a tad over 10,000 RPM Ive heard this is where the power starts so im keen to get it sorted out, After reading the forums I have found other riders have had this issue when changing to pod filters but mine is running the stock airbox and filter. When I brought the bike it had been sitting for a year and took a few good open runs to clear er out and get number 3 cylinder firing up after this I thought it'd be a good idea to check the oil so I dropped it all out there was 800ml too much in there not sure if this would have caused any damage and god knows how long the previous owner was running it like this for it was a very dirty color so I'd say it has been a fair while.
Anyway I have planned to run some injector cleaner through the fuel, ill be checking and gaping the plugs checking the tank vent tube for blockage and making sure the pilot screws are set at 3 turns out,
Is there anything else I should be looking into checking or any tests I can do to isolate the cause.
Thanks.

 

Overfilling could fail the head gasket. You'd be pouring white smoke out of the exhaust if that were the case. Flogging the piss out of it may have cleared a partial blockage, but your carbs are still going to be varnished. Yank them off, clean them up, look for leaking vacuum lines while you are at it. It really sounds like you were just running off of the main, through some stroke of luck.

 

welcome, the early 2kr,s did not have exup so is probably stock exhaust.the vin will tell.i suspect carby clean needed.

 

Take off the carbies and open the bowls.

Careful with airbox boots and carby boots as they will be fragile or may even need replacing

 

Thanks for the replys I'm confident the head gasket hasen't gone like I said she runs and sounds fine theres no chugging flat spots or other funny stuff untill it hits the 10,000 mark, the exhaust goes from 4 to 2 then into 1, I thought they all were 4 into 1 ? Anyway ill definitely pull the carbs for a clean does anyone know what the float height should be ?

 

Ok so cleaned carbs checked plugs and leads, might be running a tad lean going off the colour of the plugs, brought a new battery as I thought I had a dud one as it wouldent hold charge after 2 days of use charged and installed new battery and went for a ride still wouldent rev past 10,000 stoped off at the shops and went to start er up again and got nothing the battery had been completely drained so off I went roll starting it down the road I had to keep the revs up when indicating as they wouldent work otherwise, so now im thinking it may be an electrical problem contributing to my rev problem , any suggestions or a process of elimination I can carry out to find the problem? I have very little electrical experience so I have no idea.
I will post pics of the exhaust system tomorrow. Thanks

 

Yep.

 

Sorry should have been more diplomatic - Welcome

Wouldn't bother with injector cleaner on a carby bike. Won't really do anything and if it does it's going to make the bike run crap as carbies are way sensitive on fuel/air ratios.

If you're struggling at high RPM, just think about how carbies work - a fine balance of fuel/air. If your air filter isn't completely blocked and you're getting good air flow, then the fuel mix into the air is your issue. I'd be taking the carby bowls off as has been suggested and cleaning the jets. Make sure you do more than just "blow" them out, use a needle from a wire brush and rub gently or a bristle from a tooth brush if it is really small. You don't want to hack them up but you need to physically clear any crap from them. Get a Litetek kit (@maelstrom may be tooting his own horn but it's worth the investment) and replace the basic seals. If the carby isn't too dirty chances are you won't need a full disassembly and rebuild but its probably recommended on an older bike anyway. I have some minor tuning to go on mine, but I only did a partial rebuild and have had a few hiccups but mostly she's running well.

And don't forget the pilot screws. They need cleaning too

Good luck, plenty of good advice around here (most of which doesn't come from me by the way!)

 

2kr non exup exhaust is 4 into a collector with 1 outlet to muffler.

 

Hey guys attached some pics of the exhaust system couldent be bothered taking it off again so just took a few along the length of the system pics 1 and 2 show under the bike where the header pipes have been extended and join into two single pipes as seen in pic 4 then these two pipes join to a collector just before the silencer. I have a new RR here but the one i took off was a 6 pin the new one is a standard 4 pin can anyone tell me which coloured wires are supposed to go to which pin. Cheers

 

I have 3 yellow wires coming from the stator 1 red wire I presume from battery positive and 1 black which is grounded to the frame. So five wires only four pins and no diagram.

 

Ok so got the rectifier wired up and took some readings with the multimeter and this is what I got.

Battery 12.5v
Battery at 4000revs 12.8v

Voltage at all combinations of white wires from stator 31v at 4000revs

No amperage between negative terminal and negative post.

 

Your battery voltage looks too low, both idle and while charging. To me that indicates either a buggered battery (possible) or stator problems.

I'm not sure the voltage measurements you took on the stator mean much, without further context. Try this:

http://2fiftycc.com/index.php?threads/howto-testing-a-motorcycle-stator.2052/

 

Doesn't disconnecting the speedo normally limit the revs? At least that's what I've read most bikes do.