My son bought Murdo's 93' ZZR250 so he could ride something now, while we still work on the GSF250 Bandit.. Took it for a test ride and about the only thing I didn't like was the amount of vibration that was coming through the handlebars at anything over about 70kph. Insane amount to the point where my hands were numb and tingling after 15-20 minutes on the bike and my hands didn't return to normal for about 30 to 40 minutes. I realise everyone has a different idea of the feel of vibration in their bikes according to what they are used to.. for me - my VFR has zero vibration unless I am in the upper reaches of the RPM scale. Same for my GSX1400. Both bikes are very smooth. anyway. I set about trying to get rid of the vibration on the ZZR as I knew that if I didn't, then my son would not be wanting to go on long rides - I certainly would not want to ride the bike, so would hardly expect him to. For those interested - the result was extremely successful - hence the following write up.
Original bar end is a solid bar of aluminum.. but when you have the tools and a workshop... anything can be fixed..
I cut the curved part of the bar end off. Making the bar 235mm in length. Then drilled a 3mm hole for about 3cm down the middle of the bar end. Then drilled down the same hole with a 5mm drill bit. The 3mm hole being used as a pilot hole. After that I threaded the hole with a M6 x 1.0mm tap. Getting around 2.5cm of useable thread I would think down the hole. This was the size of the screws I had to hold the bar ends on. The bar ends were originally from my GSX1400. I have since put even heavier ones on the 1400 as I changed the handlebars to Renthals and found the heavier weights on the bars were better for vibration reduction. The OEM GSX1400 bar ends weigh about 325 grams from memory.
For a little more vibration reduction I also made up some foam rubber spacers to put in-between the top triple clamp and the mounts of the clip on bars. The bar ends would be removing the majority of the vibration, but I think having these will also help a small amount and every little bit counts.
I then had some thick rubber washers (thanks Bunnings) which I then installed between the bar end and the clip-on before tightening up the high tensile phillips head screw into the clip-on to hold on the bar end. This is the end result.
Went for a test ride and the difference is like night and day now. As level from 1 to 100. 100 being totally stock before this mod - call this maximum vibration 0 being no vibration at all. I would now say that this mod - the vibration level is now between a 5 to 10. from a totally stock level of 100. I can still feel the smallest amount of vibration in the bars - but it is nothing like it was before. Before the mod, even lightly lifting my hands off the bars (not hanging on)the vibration was still felt. The mirrors were also to the point of useless as well. Strangely the heavy bar ends have also had a positive effect on the mirrors. Whilst still a little blurry at speed - at least now, I can tell that there are cars coming up behind me from a fair distance away as well. Before - I had no idea what was behind me. hmmm, might buy some lead weight or stainless steel weight and mount them on the inside of the fairing on the mirror mounts to see what that does. Next step will be to remove the grips and put some dual compound gel road bike grips on, similar to what I have on my other bikes - I think that will then be the best it can be. Anyway, hope this is helpful to someone as I'm sure it can be done on other bikes that have solid clip on bars. To be able to install some bar end weights. As the bike is really quite comfortable now and I wouldn't hesitate to take if for a long ride now - especially once I get some dual compound gel grips on.
Nice work there. I never thought the ZZR had much vibration through the bars, but then I ride a couple of big singles so my perspective would be a bit different.
I was surprised by how much vibration was coming through the bars on the ZZR. My hands were numb after riding for an hour. My arse must have felt sorry for them as it started to go numb shortly after that! As Murdo said, it's probably seems worse depending on what you're used to riding.
Totally agree. My VFR is unbelievably smooth. No vibration at all through the handlebars or footpegs. I've test ridden v-fours before when I worked in my brother's motorcycle shop, building the bikes out of the crates when they were delivered. But never owned one until now. Heard so many reports of the engine being almost vibration free, now that I own one, I can only agree. The 1400 is smooth, but does have the tiniest bit of vibration between 2500-3000rpm, which equate to around 80kph in 5th. With the 80 kay zones around parts of Tamworth, it became noticeable as the VFR has nothing with regards to vibration. That said - I did an oil change the other day on the 1400 as I wasn't happy with the synthetic penrite I put in it. Change to Fuchs 10w40 semi-synthetic (nice price from SupercheapAuto). Made quite a difference to engine smoothness, gear changes etc. Hence when I got on the ZZR, for me it became "un-rideable" for any long distance highway riding, with the vibration through the handlebars. But as mentioned, I'm used to the V-Four, so will compare everything else I ride, to it.
Strange on the comment's of the ZZR 250 as i was never aware / heard of the vibration's. Purchased a new 1994 ? GPX 250 (as it had a lower seat height over the ZZR ) and that was super smooth to ride.
Agree. I am not an expert on the ZZR250, but I did ride a mate's GPX250 years ago and I definitely don't recall it having issues with vibration either.
Well, the vibration through the bars on the ZZR would be akin to holding onto a braun electric toothbrush only 10 times worse in vibration. Reading on other forums, there have been other owners who have complained about the vibration in the bars at highway speeds. Around town - there is nothing to speak of. But as soon as you went over 70kph and from 80kph upwards it got progressively worse. As mentioned, its like a braun toothbrush only 10 times worse. After only a 15/20minute ride, my hands were almost numb and were left tingling for about 30 minutes after I got off the bike. it may also be the result of the fact that Murdo had the heads bored out for the new pistons/rings - so is now a 265cc.. who knows. Fact is, the bar end weights cured most of the issue. I think once I install some dual compound gel road bike grips it will be that little bit better again. But as we mentioned before, it depends on your own perspective according to what you ride. Murdo didn't think there was any vibration. But said his other bikes are big single cylinder bikes. I'm used to riding a V4 - known to be super smooth - literally no vibration at all. Like sitting on the bike without the engine running. Being that is what I am used to probably makes me over sensitive to any vibration I feel through the handlebars.
I purchased the GPX 250 for a work bike , my main ride was a 1976 BMW R90 (big twin) so i was yous'e to vibration's. But the first ride on the GPX blew my mind how smooth it was and how nice it was to ride. I'm aware that you've fitted bar end's to help cure the vibration's , the carbi's are in sync though ?. No offence meant to your mechanical knowledge , but if the BM carb's was out by a smidgen it could be easily felt , especially with Dellorto's. Just a thought.
Not sure Blue. I ride other bikes too and the ZZR numbed my hands and my backside faster than anything else I've ridden lately. I rode it to Bendemeer with the VJMC Coffee crew, so maybe I was in the "vibration" speed zone. It certainly handled and braked well. It's great that you found an easy upgrade to resolve the issue. Well done.
Murdo told me that the carbs were sync'd not long ago. So didn't bother to re-check yet. I'm also going to loosen all the engine mounts at the same time and re-torque them. Doing this made a difference on the 1400. While I'm at it, I'll check over the carbs again. I've noticed that my digital vacuum gauge is a lot more accurate than analogue gauges and can make quite a difference. Probably do this in the next day or so while I'm off work. I first tuned the GSF250 with the manual gauge. But really wasn't happy with the tune, thought it could be better. Next day I connected up the digital gauge and sure enough, the vacuum was still out when the manual gauge indicated it was OK. In case anyone is wondering, yes each of the 4 manual gauges have been calibrated to read the same/evenly. The digital gauge allows me to be way more accurate and achieve a finer/more exact tune. Frankster - I agree with the seat, it's a little firm for my liking. But will see how my son goes with it on a long ride. If he doesn't like it, I'll go see the "Chair Man" here in Tamworth and buy some softer seat foam off him and re-modify the seat.
As you've mentioned , no harm in checking the carby sync. The tool that i yous'e to use back in the day's was called a twin max , this gauge has only one needle , so it will quickly tell you if one carb is working slightly harder than the other. In the end i could balance it by ear / feel. Murdo is a perfectionist with his work , and honest to his word !.
(not so) Quick follow-up. My son and I checked all the engine mounts torque settings and they all needed some adjustment. So loosened them all off and then slowly did them up a little at a time to make sure it was all evenly done to torqued specs. Also added some dual compound grips and some heavier bar end weights. Also changed the oil to a semi-synthetic 10w40 and a new oil and air filter as well. Went for a quite ride out on the highway and it made quite a difference. Before all the work above, there was a lot of vibration also in the right footpeg - even with motorcycle boots on to become really annoying after a few minutes. The left side wasn't as bad - about 1/2 as much as the right side. Handlebars with the previous weights still had some vibration, but way better than with no weights. Now, the left side footpeg is almost vibration free and the right side footpeg is about 1/3rd of what it was before. Handlebars are also way better again with the heavier weights and new dual compound grips. I have some foam over-grips to try next.... another day. Then reading a post on this forum about the fuel filter issues of not flowing properly. I had previously noticed the fuel filter on the ZZR was only ever 1/2 full and was wondering if it was causing some issues with fueling or not. So bought some fuel hose and removed it. Didn't see the point of having it there anyway as the filter that is built into the fuel tap is so fine that no junk would get through it anyway and besides, the ZZR didn't have an external fuel filter anyway according to Kawasaki online parts microfiche. While the tank was off, my son then rebuilt the fuel tap with new O-rings as it had started a slow weep. Whilst I didn't get a chance to test ride it, the bike seems to rev a lot better now with just the fuel line and no external filter. Next job will be to play with the vacuum balance and also the idle screw mixtures. I think there is still something not quite right somewhere as at times when you give the bike a rev, it will drop to idle - no problems. Then other times - maybe the 3rd or 4th rev-up, the engine dies down to below idle at around 700 revs and whilst it doesn't stop, it struggles for a bit and then slowly comes back up to idle. When the engine comes down from higher revs sometimes it drops normally and other times, it is a bit slower to drop to idle as well. Also the idle adjustment is overly sensitive. Just a very slight turn can see it idle at say 1100rpm - but a touch (and I do mean a very small amount of turning the adjustment here) more and then it goes up to 1500rpm - doesn't seem to want to sit at around 1200-1300rpm at all. I'm wondering if there is a vacuum leak on one of the hoses or the idle screw mixture needs some adjustment. Also using the choke just makes the engine not start. Or if the engine is running (cold) and then turn the choke on - again the engine just dies. Had this problems with the GSF250 when I got it running and had to completely clean out the carbies choke circuit to get it working properly. Also took out the gauges as the bulbs had all blown - went for a ride just before dark and could barely see the gauges. Modified the seat as well and cut out the foam that Murdo put in and replaced it with some foam I bought from Greg at the "Chairman" here in Tamworth. Reshaped the seat to the way my son liked it and then restapled the cover back on. Now just need to try and take the rear end out this weekend to get to the rear shock and adjust it to be stiffer as whilst my shock spanners can get into the space, there is not enough space to adjust it up to the next adjustment notch. Dumb design that is by Kawasaki.. Might also need a new temp sensor as the temp gauge barely moves at all and the fan comes on when the temp gauge is reading about 1/4 up from cold.. which obviously is not right... as I can feel the heat coming off the engine so its not reading the right temps on the gauge, but at least the fan looks to be coming on at the right time.
