www.zxrworld.co.uk

Finally a dry day so I got the bike out for its first run and I'm a wee bit concerned.

Can someone please tell me expected RPM at 70mph when in 6th. When changing from 5th to 6th today I noticed no change in RPM or corresponding engine noise. I quickly headed to the motorway, sat at a constant 50mph and changed between 5th and 6th and back again. Although the bike seemed to be changing gear the RPM seemed identical. I cant remember the exact RPM but when I took the bike up to 70mph in 6th (I double checked I was definately in 6th!) it was screaming.

If anyone can give some expected RPM's for certain speeds in 6th gear it would be much appreciated before I take it to the garage to get checked out.

Thx.

could be your clutch slipping mate. have you checked or changed the oil recently?

Had a full service september 05 and has only covered approx 200 miles since. Unfortunately I couldnt get out on it today as the weather is absolutely terrible up here, who would live in Scotland eh!

do you know what oil they used on the service?

Castrol GPS. Would you recommend something else for the future?

reason i ask cos if you use fully synthetic oil it can make the clutch slip, Gps i believe is synthetic based, not used it myself so can't say regards performance? i always used shell.

Ive used GPS since my first ZXR. Cant say ever had any problems with slippng clutch.

that eliminates the oil then

Thx guys, still scratching my head though

Might be that there was the wrong oil in it before you bought it and contaminated the plates?

Personally id get it up on a paddock stand and take it up on each gear on tick over, youll definately know if its gone up a gear as the wheel will go faster.

Off the top of my head, 70mph is about 6-7krpm.

At 50mph the difference between 5th and 6th is probably less than 500rpm anyway. you could try it again at 70+.

I'm not really buying the clutch slipping theory, but if you want to find out I guess you'd be more likely to notice it accelerating hard above 10krpm. Again off the top of my head a standard geared bike redlines somewhere between 50 and 55mph. Find a quiet straight road and launch it, if you run out of revs before you hit 50 then maybe it is slipping.

All of this is a bit academic anyway until the weather improves enough for you to ride it

D

with the bike on the paddock stand, dont start it. Click it into 1st and then turn the back wheel forward and click up into second, keep going until 6th and see if they click in okay and with ease. you'll hear it click into each gear. Then try it wirh the engine started, as ROB B said, up on the stand with it ticking over and go up the gear box and see if you can hear it clicking into each gear. at tick over speed you will notice a differenace in the wheel speed as you click up. This might help you figure out if you have a problem.

If it does appear t obe an issue, then it might be a) Clutch, b) gear box issues.. then its time for the garage to look at it....

Many thanks for the replies folks. I'll let you know how I get on soon as.

yeah i think deviant hs got it spot on with the RPM thing.
i have noticed that the speedo corresponds with the tacco. i.e. 40mph is 4000RPM as is 90mph is 9000RPM.

6th at 70mph is 7,000 rpm mate

6th at 40mph is 4,000 rpm

thats with the sprokets i have(dont know what they are), and depends on what sprockets your running, and rember the sp had close ratio box