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Hi, new owner to an 82 model GPZ 1100. I am not so happy with the front end. It feels soft and unstable. Wobbles when crossing the white line or any unevenness on the road.
I wonder if anyone has some advice? What pressure should I have in the air valve?
Any comments appreciated!
Cheers:biggrin:
 

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Good Day Monkeyboy! I also have an '82 GPz1100. First things first...if you don't already have one, buy the Kawasaki Heavy Industries shop manual...available used on eBay and I think there has been at least one reprint by Kawasaki. Expect to pay between US$15 and $40. Well worth it. Now, to answer your question, do the easy things first, check your tire pressure ...change your fork oil (275cc for each leg), you should be running between 6 and 8 lbs max air pressure in the forks...do NOT fill the air valve with a high pressure system (like at a filling station air machine)...use a hand pump. If those don't cure your issues, then you might be dealing with worn out springs...hard to say.
 

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Hi, new owner to an 82 model GPZ 1100. I am not so happy with the front end. It feels soft and unstable. Wobbles when crossing the white line or any unevenness on the road.
I wonder if anyone has some advice? What pressure should I have in the air valve?
Any comments appreciated!
Cheers:biggrin:

Fork air pressure is not going to cure your ill handling, air pressure simply adjusts the bikes' ability to firmer or softer absorb impacts. Jack the front of the bike so the front wheel is off the ground. Pull the front tire up and down to see if you have any play in the front end. If you do now you need to check the steering stem bearings, and / or the front wheel bearings. FYI, I only weigh 155 lbs, and I have my forks and shock set at only 5 psi, my GPz handles perfect...
 

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GHOSTRIDER
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Good Day Monkeyboy! I also have an '82 GPz1100. First things first...if you don't already have one, buy the Kawasaki Heavy Industries shop manual...available used on eBay and I think there has been at least one reprint by Kawasaki. Expect to pay between US$15 and $40. Well worth it. Now, to answer your question, do the easy things first, check your tire pressure ...change your fork oil (275cc for each leg), you should be running between 6 and 8 lbs max air pressure in the forks...do NOT fill the air valve with a high pressure system (like at a filling station air machine)...use a hand pump. If those don't cure your issues, then you might be dealing with worn out springs...hard to say.
Welcome to the forum Monkey Boy! Mcdroid gave some good advise here! While you have the front tire off the ground, grasp the forks at the axle and shake the forks fore and aft to check for free play or rattle in the steering head stem bearings, there should be zero play in the steering head! If there is slight play in the stem assembly a simple adjustment (tightening) will eliminate the play. Motorcycle front ends can be very sensitive to road conditions and those conditions are magnified if the harmonics and balance are not dead nuts on. Maintaining equal oil levels in each fork tube, wheel balance, tire condition and steering head bearing adjustments as well as equal air pressures can ruin a riders day! You really need that manual Mcdroid suggested because it depicts procedures,tools,torque specs and levels necessary for maintaining your bike. Good Luck and Merry Christmas!
 

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I just fixed a few issues like this on my 82 kz1100b2, the steering bearing were dry as a bone, and were in pretty bad shape, so I changed those with a new set of all balls brand steering bearing kit (if anyone needs one let me know, I accidentally ordered 2 for some reason). that made the biggest improvement to my handling. Next I changed the fork oil and fork seals, I went with a slightly heavier fork fluid since it is a heavy bike (I think 15w). the last thing not to over look is a old tire. old tires can wear weird and cause strange handling issues.
Also, when you have the forks apart, check the fork slide bushings, top and bottom for wear, they should have a black coating on one side of them, it they look copperish, replace them. Mine were totaly shot, and I need to order some for the next rebuild I do.
 

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I'll go ahead & suggest getting new progressive fork springs & maybe new rear shocks.
This will be just a waste of money if all's Monkeyboy has is bad/ mis-adjusted steering stem bearings. You ALWAYS systematically check the simple things first before going extreme....
 

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Eddie Lawson is God!
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What? A derivative of the J model handling poorly? Say it isn't so. Kawasaki discovered handling with that bike, so something's wrong. Air is the answer to the question nobody asked. You don't need it. First, lube/replace the steering head bearings, Reassemble the front end. After adjusting the steering head bearings to the Kawasaki factory manual specs, get yourself an HD Dyna Superglide manual and perform a "Fallaway Adjustment" This adjusts the S/H/B PERFECTLY. Now slide the tubes out of the steering head WITHOUT DISTURBING IT. Dissasemble and clean the fork legs, replace the fork seals with Kawasaki OEM only. Take the original thirty year old fork springs and relocate them to the trash can of your choice. They're JUNK. Install Race Tech or Progressive Suspension fork springs. Fill fork to recommended level with 10wt (If you're a sprite) or 15wt (If you're a fast fatso like myself) fork oil. I use HD Screaming Eagle Heavy.
Now reassemble the whole deal. Replacing the tire if necessary. If you have a death wish, run a Maxxis or Cheng Shin. If you have something to live for, Metzeler or my preferred Bridgestone BT45 V. Did the puking fork soak the brake pads. You know what to do. Good.

You think you're DONE. You haven't looked at the BACK. Disassemble/lube the swingarm pivot bearings. Take the screen door guides Kawasaki called shocks, and make them join the fork springs. Replace them with ANYTHING that fits, and is NEW. Anything is an improvement. Adjust the chain until the swingarm pivot and the rear axle is parallel within ONE millimeter. Anything bad, tire, chain and sprockets is GONE.

It's a free old POS NOW, in her day, she'd outrun a Ferrari.
 

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I keep all my air cooled muscle bikes suspension's BONE STOCK. Why? I'll get less speeding tickets that way. Air cooled chassis headshake is like a speed warning device that kicks in at 45 mph... :mrgreen:
 

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GHOSTRIDER
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I keep all my air cooled muscle bikes suspension's BONE STOCK. Why? I'll get less speeding tickets that way. Air cooled chassis headshake is like a speed warning device that kicks in at 45 mph... :mrgreen:
My brother in laws H1 would head shake with the key in his pocket!:eek:
 

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Navy Vet Search & Rescue
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get yourself an HD Dyna Superglide manual and perform a "Fallaway Adjustment" This adjusts the S/H/B PERFECTLY.
I don't think I'm going to be buying an HD service manual just for making this adjustment but it would be interesting to see what this is since I've seen you speak of it a few times.

P.S. Ratvespa that "skivvies" comment sounds suspiciously like a current or former Navy man. :lol:
 

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Eddie Lawson is God!
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A tapered roller bearing needs a certain amount of preload. It provides the correct friction so the steering head isn't rattling (Because it's too loose, and causes headshake) or too tight (causing stiff steering and a weave). Basically, it involves disconnecting the clutch cable (Because it imparts enough force to affect the measurement) propping up the front of the bike until the front wheel JUST clears the ground (with the bike level) and by tapping the front wheel, determining how tight the bearings are. You'll find this in a manual for an HD with a skinny front tire. NOT a Springer Softail.

The first time I did this in a Japper shop, they came UNGLUED. Now this is my method for adjusting ALL head bearings. For bikes with fat front tires, I do it like a Road King.
 

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you are correct,I have a 06 dyna streetbob that has front tire wobble, returned to dealer and told me it was normal, I said I dont think so, they claimed they checked fall away 2 times, still have a wobble if I take one hand off grips, I told them this and they said you should not ride with your hands off grips , I got a Z1 that I can ride with no hands............I presume it may be a bad tire, original dunlop...............from all these posts I really never thought about unequal amounts of fork oil , bad springs ect , thanks for the insights, the harley is just a garage dust collector, the battery tender and the bike are great friends lol
 

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Snugging up on triple tree bearing prelaod is an old skool trick to minimise headshake on motocross bikes. Tried this on my KX500 which has nasty headshake in certain circumstances, but the tightening was not enough, I eneded up buying a steering stabilizer, and that was the end of it..
 

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GHOSTRIDER
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A tapered roller bearing needs a certain amount of preload. It provides the correct friction so the steering head isn't rattling (Because it's too loose, and causes headshake) or too tight (causing stiff steering and a weave). Basically, it involves disconnecting the clutch cable (Because it imparts enough force to affect the measurement) propping up the front of the bike until the front wheel JUST clears the ground (with the bike level) and by tapping the front wheel, determining how tight the bearings are. You'll find this in a manual for an HD with a skinny front tire. NOT a Springer Softail.

The first time I did this in a Japper shop, they came UNGLUED. Now this is my method for adjusting ALL head bearings. For bikes with fat front tires, I do it like a Road King.
My "79" Kawasaki service manual outlines this very procedure. What you touched on in an earlier post and what doesnt get discussed much is the relationship between the rear wheel and swing arm and the front forks and wheel. Not many riders take the time to fully understand the dynamics involved therein. Im all ears when it comes to this subject because although it is a narrow band of expertise, it is very deep! Jeff Saunders helped me realize some of those "at speed" dynamics between tire,wheel,forks and head stem. I still ask myself why these brand new late model rockets still need $800 Steering stabilizers? Ive taken every step to tune my frontend and she gained a noticeable amount of stability at higher speeds, but when I roll out of the throttle after 9000 rpm in 5th gear, its game on because when that rear end unloads, it goes into a slow motion side to side wave good bye(well over 100mph) to whatever I just blew away:eek: I expect its related to the fact that my bike is a shaft drive and not a chain drive. Ive replaced the swingarm bushings with roller bearings and grease zerts to no avail. She loves getting up to speed , its the slowing down she dont like! Any insight?
 
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