d1 front sprocket torque values

[David Richard]

hi im in the uk and we have a well established called haynes manuals that cover many things and they list a front sprocket torque at 90 ft lb and i have a kawasaki book that say 72 ft lbs ,that book is for a c1 model now i think the heavy industries know their bikes but thats quite a big differance in values it just makes you wonder why .the reason i ask is that when you attempt to undo a nut from the factory how bloody tight do they do up to .i used a air rattle gun but had to borrow a mates bigger compressor .i remember a member here a couple of years had a 6 ft bar on the 27 mm nut and it still held on leaving him to cut it off ,thanks any thoughts dave

[Eddie]

Hello,

Personally I would always go with the factory manual, if they don't know who does! Haynes are good but i have come across inaccurate info before on other bikes. I know what you mean about the nut, i had to borrow a monster air gun to get mine off my 1100, i think they do have a self tightening nature as you use them.

Cheers eddie

[hugojose]

I have a 750 C1, and have a Kawasaki factory manual, and also a Haynes covering the 750/550 w/out saying years.

Yes, the Kawasaki manuals says it is 98 NM or 75ft-lbs for the front sprocket nut.

The Haynes says it is 125 NM or 92 lb ft.

Personally, I think is a mistake. Don't see any reason as to why this nut would be as tight as the clutch inner basket nut. Additionally, it has this locking bent plate on it to secure it. The Factory Manual is meant for dealer mechanics, ....-Haynes tries to make it user friendly for the owner, but they copied most of the data and diagrams from the Factory Manuals, no need to reinvent the wheel, but some mistakes get by

....by the way my Haynes says the torque for the 550 front sprocket nut is 10 NM or 7.5 ft-lbs, ........of course is a typo. I think they meant to say 100 NM, which would about right.

I have no problem getting this nut (or the clutche's) out, with an inexpensive electric impact gun capable of 200 ft-lbs.

[David Richard]

thanks for your replys lets hope we can use them a bit this year

[gazzz]

I have a 750 C1, and have a Kawasaki factory manual, and also a Haynes covering the 750/550 w/out saying years.

Yes, the Kawasaki manuals says it is 98 NM or 75ft-lbs for the front sprocket nut.

The Haynes says it is 125 NM or 92 lb ft.

Personally, I think is a mistake. Don't see any reason as to why this nut would be as tight as the clutch inner basket nut. Additionally, it has this locking bent plate on it to secure it. The Factory Manual is meant for dealer mechanics, ....-Haynes tries to make it user friendly for the owner, but they copied most of the data and diagrams from the Factory Manuals, no need to reinvent the wheel, but some mistakes get by

....by the way my Haynes says the torque for the 550 front sprocket nut is 10 NM or 7.5 ft-lbs, ........of course is a typo. I think they meant to say 100 NM, which would about right.

I have no problem getting this nut (or the clutche's) out, with an inexpensive electric impact gun capable of 200 ft-lbs.

I suppose Haynes is correct about Zephyr 550 sprocket BOLTS. The thing is that 550 has no sprocket' nut. Its sprocket is secured by two 6mm bolts. So 10Nm seems to be correct torque for 6mm bolts. Take a look at page 5-17 of Haynes manual.

And Haynes is not entirely wrong about 125Nm for the front sprocket. It is well known that Zephyr 750 engine is a direct descendant of KZ650 and KZ750 engines. And it is well known that the furthest development of Zephyr 750 engine is ZR750 engine. And while the earliest factory manual for KZ650 states 7.5-8.5 kgm (which corresponds 74-83Nm), factory manual for ZR7 states 125Nm (and even 127Nm in 5th edition dated by the year 2005). ZR7 front sprocket nut' part number superseded part numbers of Zephyr 750 and KZ650 sprocket nuts.

My Zephyr 750 is equipped with a 4th set of chain/sprockets. Every set lasted around 30K kilometres. Nut is still original and every time I tightened it according to Haynes manual. There were no issues with it.

[Freddy]

There are many inconsistencies between the genuine factory manual and Haynes manuals. Always use the factory manual numbers, they will be correct.

In the case of the sprocket nut, it is 72 ft/lbs.

P.S. The reason it couldn't be undone with your impact gun, my guess, you were likely using a relatively inexpensive 'single' hammer gun. These things struggle to even undo a tight car wheel nut. A professional grade 3 hammer impact gun will spin of a 72ft/lb nut effortlessly even using a small capacity compressor. It will because it'll have it done with just a couple bangs before the small tank pressure has a chance to drop. The gutless gun will chew lots of air struggling going nowhere, hence why a bigger capacity compressor worked.

I originally bought a budget gun and sockets in a plastic case. The sockets and case were well worth the price, the original gun is now a paper weight.

[David Richard]

hi thanks for that freddy i went to 75 ft lb but eddie made a good point about them over time self tightening over time and i always bend 2 tangs back over the nut

[gazzz]

Decided to add the latest version of Zephyr 750 Factory Service Manual to my collection. Part number for manual is 99924-1138-03. Printed in 1997.

It arrived today. And guess what? Just as I expected, it states 125 Nm for the front sprocket nut.

Haynes manual was printed in 2000. So now we all know that Haynes information about the front sprocket nut torque is correct and up to date.