99 ZX6R Knock and vibe

[Gregorious77]

I got my ZX6R before christmas and have been having a few little issues.

First it has a K&N and race can.

It has a dynojet kit fitted but it has been back firing through the carbs and had a vibe and a slight knock and was lean so I decided to strip the carbs for a clean up.

The main jets are the ones for the stock can and are too small 126 and 130, instead of 128 and 132 for race can.I raised the needle a clip to richen mid range incase it was pinking.

I have put the stock can back on while I order some jets but it is still poping back through the carbs now and then normally when I open the throttle a tiny amount after deceleration, the needles are still raised 1 clip.

the engine has a knock only on acceleration which I can feel and hear but not once the induction starts roaring so its not very loud, I can feel the vibe on decelleration but cant hear anything.

Is likely to be a rod, mains or something else? is a cam knock noticable on this level?

milage is 10,000 miles so not high.

There is a crank with rods on ebay for 60 quid 6000 miles, but onviously no garentee that its not also fucked.

upon a search of the web everyone says these engines are noisy and rattle but that does not seem right to me.

Any suggestions are greatly appreciated.

[lorenzo]

Have you had it on a dyno? To be honest I've no idea what to suggest in temrs of diagnosis, but if you take it for a simple fuelling run you'll know fairly cheaply what your fuelling's like and it the carb settings are just a red herring and you should be looking at the engine or electrics. Which reminds me, in the past, mainly on suzukis, I've had an issue that sounded similar to yours, which was a combination of a fairly flat battery that hadn't survived the winter, and unsync'd carbs. The flat spot with the little pops was due to a bad spark and the unsync'd carbs made the timing chain rattle a bit at lower revs.

[buster]

I've a 2000 model 6R and used to be a member of a 6R forum* and these engines are bullet proof, bad fuelling is probably the cause.

Try these guys for advice http://www.ninja6zone.com/forums/homepage.php

*Only reason I left was the proliferation of american slammed/stretched 6R's and therir owners taking over the site

[Gregorious77]

I am going to phone dynojet today and get the correct jets. I have balanced the carbs already, it was the first job I done along with oil, filter and sparks.

The battery may be on its way out as the headlight dims when the brake light comes on at idle. that would explain why it pops when I open the throttle after braking I guess.

I phoned my local dyno centre and he quoted around £140 for fueling setup, does that sound a bit pricey.

[Gregorious77]

My local shop have a dynojet dyno and quote

Dynojet Initial Set Up

During the machines initial set up it will be run up to ascertain its base settings with regards to fuelling and ignition settings.Corrections and adjustments will be then be made to remedy any anomalies during its first run to establish a base line for further improvements.

£52.88

I would not let them touch my bike though.

[lorenzo]

Yep, i agree with Mille, it's not a bad price and you might, if you shopped around be able to save perhaps £30 or something, but to be honest, I'd be looking at recommendations of a job well done rather than trying to get the best price. It's pointless paying £100 if you have to go back to the £140 place 2 weeks later because you're still not happy.

Where abouts are you? There's a place in Runcorn I use who're great, and they're pretty cheap too, £120 I think.

[millerich]

While we're talking Dyno centres does anybody have any experience of JHS in Bristol? BiL is getting a Remus can for his VFR and I suggested a fuelling run after fitting it just to see if everything was hunky dory. That would be his closest Dyno centre.

[millerich]

Thanks Millemille. I think we'll give them a try then. If nothing else it'll worth it to hear his 800 and my 750 singing on the dyno.

[rndnick]

Sorry Gregorious77 for the slight thread hijack but www.timblakemoreracing.co.uk also in Bristol did my Dyno run, £30 for a run & print out with some helpful advice from the operator.

[Gregorious77]

The dynocentre come recomended so I am happy with £140 Doubletake Motorcycles in southampton

[Gregorious77]

Just need to find the cash really due to imenent baby arrival!!

[blow_away]

Sorry Gregorious77 for the slight thread hijack but www.timblakemoreracing.co.uk also in Bristol did my Dyno run, £30 for a run & print out with some helpful advice from the operator.

+1 for Tim Blakemore. JHS is great at what they do, but nowhere near as sociable.

Also +1 sorry for the hijack

[fran9r]

I got my ZX6R before christmas and have been having a few little issues.

First it has a K&N and race can.

It has a dynojet kit fitted but it has been back firing through the carbs and had a vibe and a slight knock and was lean so I decided to strip the carbs for a clean up.

The main jets are the ones for the stock can and are too small 126 and 130, instead of 128 and 132 for race can.I raised the needle a clip to richen mid range incase it was pinking.

I have put the stock can back on while I order some jets but it is still poping back through the carbs now and then normally when I open the throttle a tiny amount after deceleration, the needles are still raised 1 clip.

the engine has a knock only on acceleration which I can feel and hear but not once the induction starts roaring so its not very loud, I can feel the vibe on decelleration but cant hear anything.

Is likely to be a rod, mains or something else? is a cam knock noticable on this level?

milage is 10,000 miles so not high.

There is a crank with rods on ebay for 60 quid 6000 miles, but onviously no garentee that its not also fucked.

upon a search of the web everyone says these engines are noisy and rattle but that does not seem right to me.

Any suggestions are greatly appreciated.

On the 9, the needle jets are pressed in. The dynojet needles wear them, which wears the needle jets...which you can not replace. I'm guessing the 6 is the same, but if they are replaceble a set of needles and needle jets would sort it. If they arn't, new bank of carbs. I would suggest the spitting through the carbs is due to over, not under fuelling. This can be checked by dropping the needles and see if running is improved.

The ram air pipes can also affect the part throttle response -trace the float bowl vent line to the front of the bike, making sure no kinks/splits are allowing pressure to escape.

I am going to phone dynojet today and get the correct jets. I have balanced the carbs already, it was the first job I done along with oil, filter and sparks.

The battery may be on its way out as the headlight dims when the brake light comes on at idle. that would explain why it pops when I open the throttle after braking I guess.

I phoned my local dyno centre and he quoted around £140 for fueling setup, does that sound a bit pricey.

Dynojet stuff and correct jets should not be used in the same sentance! The headlights on mine dim when returing to idle, it's nothing to worry about. I would check the plug gaps are correct, but generally if it's running OK at high revs they will be OK.

[Gregorious77]

Got my dynojet jets today and fitted them, turns out the ones in the carbs were the right numbers after all I just missread one but I think they maybe counterfeit!

I know this sounds strange but I saw this link when searching for the right jets linky and just putting the proper ones in has made a world of difference even just to cold start.

old jets are stamped rough and do not look like the ones I received today.

Jets look the same but not the stamping on them.

Think ill take some pics and email dynojet uk.

Fuck knows if the needles are ok but a quick blast showed a lot more pull on the ass cheek dyno.

will know for sure the difference once I ride to and from work tomorrow.

need to do another balance though, not sure my home made balancer is super accurate.(was ok on my fazer)