Fork oil capacity

Anyone know for '83 XJ750 Maxim?

 

FORK OIL:


Unlike motor oil or gear oil, fork oil's major purpose is not lubrication.....rather, it acts as part of the suspension system, providing both damping and rebound control functions. The different "weight" or viscosity of fork oils allows you to modify the ride and handling characteristics of your bike in a fairly simple way.

And yes, it IS a lubricant also!

Although many people----including, uneblievably, Yamaha itself----recommends the use of engine motor oil as a substitute for fork oil, this is not a very good idea. Engine oils (or any multi-viscosity oil) uses additives and detergents that, while wonderful in for their intended purposes inside an engine block, tranny case, or rear drive unit, are not such a good idea inside forks. Forks operate at a much lower temperature and temperature RANGE than engine and drivetrains do, and thus do not need all those additives. And fork oil also tends to contain higher percentages of molybdenum disulfide and anti-foaming agents than engine or gear oil, both of which are very important to proper fork operation.

As a small example.......most motor oils are of a multi-viscosity nature (such as 10W30) which change their viscosity in relation to their temperature (thin when cool, thicker as they warm). A very necessary and useful feature for an engine, where you do not want your oil thinning out as the engine warms up. Not such a good idea for your suspension----unless for some reason you WANT your handling characteristics to change (get stiffer) as the forks heat up!

Proper fork oil levels and scheduled change intervals are important for fork performance and fork part longevity.....water contamination, as well as particulate wear will accumulate in fork oil, and since there is no oil filtering mechanism within your forks, the only way to get the grit and gunk out (before it chews up your oil seals and slider bearings!) is to change your fork fluid regularly. Yamaha recommends a fork fluid change every 10-15,000 miles or every 2 years. If you just bought a used bike, we recommend you do a fluid change as soon as possible, because just like other routine maintenance tasks (besides engine oil changes), this is one that has very likely been ignored for the last 10-12 years!

Fork oil capacities and recommended weights are as follows. The amounts listed are per fork tube:


XJ550 Maxim: 272cc or 9.20 fluid ounces. 10W fork oil.

XJ550 Seca: 230cc or 7.78 fluid ounces. 10W fork oil.

1980-81 XJ650 Maxim and Midnight Maxim: 262cc or 8.86 fluid ounces. 10W fork oil.

1982-84 XJ650 Maxim: 278cc or 9.40 fluid ounces. 10W fork oil.

1982 XJ650RJ Seca: 236cc or 7.98 fluid ounces. 10W fork oil. Fork oil level is specified as 400mm (15.75") below the top of the tube without the spring installed, forks fully collapsed.

1982 XJ650LJ Turbo: 238cc or 8.04 fluid ounces. 10W fork oil. Fork oil level is specified as 180mm (7.09") below the top of the tube without the spring installed, forks fully collapsed.

1983 XJ650LK Turbo: unknown.

1985-86 XJ700 non-X: 383cc or 12.96 fluid ounces. 10W fork oil.

1985-86 XJ700-X: 389cc or 13.16 fluid ounces. 10W fork oil.

1982 XJ750 Maxim: 257cc or 8.69 fluid ounces. 10W fork oil.

1983 XJ750 Maxim and Midnight Maxim: 257cc or 8.69 fluid ounces. 10W fork oil. NOTE: owner's manual states that the fork oil capacity is 278cc (9.40 fluid ounces). It is unknown which measurement is correct.

1981-83 XJ750 Seca: 309cc or 10.45 fluid ounces. 20W fork oil.

1983 XJ750 E-II Seca or 1984 XJ750RL Seca: 286cc or 9.67 fluid ounces. 5W fork oil. Fork oil level is specified as 168mm (6.61") below the top of the tube without the spring installed, forks fully collapsed.

1983 XJ900RK Seca: 286cc or 9.67 fluid ounces. 5W fork oil. Fork oil level is specified as 164mm (6.46") below the top of the tube without the spring installed, forks fully collapsed.

1982-84 XJ1100 Maxim and Midnight Maxim: 210cc or 7.10 fluid ounces. 10W fork oil. Fork oil level is specified as 210mm (8.27") below the top of the tube without the spring installed, forks fully collapsed.

IMPORTANT NOTE: the above fork oil VOLUMES are for use only when using the stock fork springs. The use of aftermarket performance front fork coil springs will change those volumes, since aftermarket springs are thicker than stock----and thus displace more oil. Using the stock oil fluid VOLUME with aftermarket fork springs is a sure way to OVERFILL your forks, with the very real possibility of blowing out fork seals.

Unlike with your engine oil, where a bit too much or too little oil volume in the crankcase is not really a significant concern, with fork oil, too much or too little can cause real problems (too much oil can result in blown oil seals and a stiff, harsh ride, while too little oil volume results in excessive foaming, a soft mushy ride with possible bottoming, and erratic fork performance and lots of front end "dive" upon braking).

A better way to determine the amount of fork oil that is needed and necessary is via the measurement of the fork oil LEVEL within the tubes.....sort of like measuring the oil level with a dipstick. Yamaha does not specify this level for all models; and in any case, if using aftemarket springs, the factory oil level recommendation is not always useful. The maximum oil level should be 5-1/2" (140mm) below the top of the inner fork tube, measured with all internal fork tube components installed EXCEPT FOR THE SPRINGS, and with the inner fork tube fully collapsed into the lower (outer) tube.

In order to be as accurate as possible, we recommend the use of a suitable measuring device, such as the HCP1728 oil level syringe listed further below.

And finally, the fork oil viscosity can be changed from the factory recommendations to give a softer or firmer ride.......the lower the viscosity, the thinner the oil, and the softer the ride (i.e. 5W oil is thinner than 10W which is thinner than 20W, etc.) In this regard, you would certainly be correct in thinking of fork oil as a suspension "tuning tool"! Note that a thicker oil viscosity will have much more effect on the fork "rebound" characteristics than it will on the fork compression dampening function.

 

Thank you very much Len!

You have been an amazing help in getting parts and supplying info!
:wink:

 

for an 83 seca 750 thats 10.94 fl oz per fork tube right.

 

Yea is that for both fork tube or 10.45 fl oz per tube?

 

yesum

 

thank u

 

yesum

 

I thought you were confused over quantity, you asked about 10.94... cool

 

Yea my fault i mis remembered the quantity.

 

No worries at least you're sorted, not like the poor guy with a hacked up wiring loom that's tying my head in knots in another thread!

 

yea no question is a stupid one when it comes to motorcycles, any of them in my opinion.

lol is that the "turning over but not cranking" thread, sounds counter-intuitive if you think about it to much ROFL. i was gonna chime in but yea im not a fan of electrical stuff. I can figure it out but i choose not to if i dont have to lol. anyways yea i just noticed you joined march 1st and your red lining already HOLY CRAP SON! Im assuming your not bike isnt up and going yet

 

lol I know, I noticed it flicked over to red liner when I posted on eco's thread a while back now, post whore or what Nah, well bike's running sweetly just Godawful weather so no playtime...

Yea that thread's the one. I know, it didn't sound right, I thought before I read it maybe the starter was spinning but not engaging like with synth oil or something... I like to get my head round chewy electrical stuff IF the wiring is as the manufacturer intended, not when there's relays with direct battery lives & earths bolted to coils etc :cry:

May have figured what the P/O did with it now but not 100%, really when it gets that bad you need to see it in person.... Hey anyway I best shuddup 'bout that, this is a fork oil thread lol 8O

You're right though, it's better to ask the question than get oil everywhere or have pogo-forks

(hmm, think I just about pulled it back round there haha)