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Hello folks... new member here. I recently picked up a 1981 GPZ550 project (practically free, in a trade) and I could use a little help/info figuring out some things that have me confused. I've worked on lots of dirtbikes and Harleys since I was about 12 years old (I'm 32 now), so I know my way around motorcycles pretty well - BUT I have no experience with a GPZ like this one. The bike is in pretty rough shape but carbs are clean and it's mostly complete (minus airbox, seat, and misc other items). The guy I got the bike from knew pretty much nothing about it... he got it in non-running condition and sat on it for 5 years or so, and lost interest in the project. Being an unknown motorcycle the first thing I wanted to check was if the engine even spins. Since I didn't have a battery in it, I decided I would try to spin the engine manually by putting it on the centerstand and using the rear wheel with the bike in 1st gear (with sparkplugs removed). I could not get the wheel to turn in either direction. Removed rear caliper to be sure it wasn't causing resistance, so thats not the issue. Also removed the chain, and wheel spun freely with chain removed, so I ruled out bad rear wheel bearings or seisure on the axle as a cause. Shouldn't I be able to spin the motor in the way that I described? On every bike project I've messed with in the past I could check if the engine spun just like that - with the rear wheel suspended you can turn the motor in 1st gear using the rear wheel. I figured my basic test would work on the 550 just the same, but not getting results? Tried shifting it into 3rd to rule out a possible problem with 1st gear, but the bike won't go into 3rd. It will only shift into 1st or neutral. Tried spinning back wheel or pulling clutch in and out while pushing the shifter upwards to get it into 3rd, still no dice. When my tests using the rear wheel didn't tell me anything, I decided to put the bike in neutral and momentarily hook a spare bike battery directly to the 2 terminals on the starter solenoid. This resulted in healthy, fast, normal sounding cranking of the engine. Engine spun freely using the elec starter. So... now I know that the engine is not seized and that all cylinders at least make enough pressure to blow my finger off the hole (haven't measured actual PSI in each yet, one thing at a time). Okay... so back to the trans. If I now know that the engine spins... what does it mean that I can't turn the rear wheel with the bike in 1st gear? Can someone put their GPZ on the centerstand in 1st gear and see if they are able to turn the motor? Also what about it not shifting into gears other than 1st and neutral? Does this mean that the trans is damaged, or is this normal behavior for a GPZ that isn't running? I know my old Harley Panhead (with engine not running) will freely shift into 1st and Neutral, but won't shift into higher gears unless I play with the clutch or spin the back wheel (I guess this helps get the syncros aligned). I'm ready to jump into this project, but don't want to go through the trouble/expense of getting it running if I can determine right now that there is a trans problem. A trans problem would essentially render the bike worthless to me, as I haven't got the time or patience to rebuild a transmission. It would be cheaper to just dump it and move on to the next project bike if thats the case.

Anyway... hope that my post makes sense, and any input greatly appreciated. I'd appreciate any info, or suggestions as to what other basic tests I might perform to let me know whats going on with this thing. Thanks in advance.

If the rear caliper and wheel arent seized, I would put the chain back on and rock the bike back and forth to try and run it through the gears. see if that does the job. Have you checked/changed the oil yet? if the bike has been sitting for a long time you never know what gunk is lying in the crankcase. I think Harleys have seperate engine/gearbox units but the Jap bikes are all in one.Whatever is in the crankcase is in the gearbox and the clutch. Pull the drain plug and see what comes out. .
Enjoy.

Hi. My 550 ltd has a positive neutral finder, so unless you are moving, it will not shift to 2nd. makes it super easy to find N when parking it, but a pain to do what you're doing. I also just got a parts 550 and tried the SAME think you are doing. I could not for the life of me get I to spin. I took of the right front cover (the timing advance is under there) and put a wrench on the crank and turned it over by hand to make sure it was free. it was.

Look for member Loudhvx - he has an AWESOME 550 site and has links to some manuals there.

In the future if you want to slowly turn the engine over (with the transmission in neutral) you can use a wrench on the large nut on the right hand side of the crankshaft. It's located under the small right engine cover where the pulsing coil is. Ed

Great info, thanks guys. I was convinced the trans had been trashed but glad I took the time to chexk it out and ask questions. I'm gonna clean/benchsync the carbs, change the oil, put in some new plugs, hookup my test gas resivoir and see what she says. I love bringing these old neglected things back to life. Last project was a 78 cb750 SuperSport. It sat outside in a guys backyard for 7 years with no airbox and the carb bowls open. Took me exactly 30 days to breathe life back into that relic. Hope my luck is as good on this GPZ. if all goes well mechanically, I've already got my build all planned out. Thinking rigid frame board tracker with twin 19" harley mags front and rear and a gsxr inverted front end. All parts already on hand, was just waiting for the right machine to come along. Thanks again guys, much appreciated.

Heres a link to Loudhvx post. All the manuals and carb stuff plus the warnings are in his sig. 81 was the best year for the 550. A good carb clean she will probably start right up. Glad to see another one saved

www.kzrider.com/forum/11-projects/597736...motorcycles?start=20

It is usually much much easier to turn the engine over by rotating the tire with the transmission in top gear, 5th or 6th gear, not first gear.

If you're gonna chop it, I'll trade you my 81 550 lTD straight up

I've never ever seen a 550 gpz in person, and I'd love one.

Kawasaki has a feature preventing shifting from neutral to higher gears. The counter shaft must be spinning to shift up. I got a call from one of the members with this problem. He was frantic. He was going to split the cases again but told me everything looked good insde, twice, he had just done a complete overhaul and wants to put the thing back together. I assured him I've been there too. After all these years working on these things, I try to shift up, then remember this feature. I plug it back into the bike and it works fine.
Steve

With the extra compression of the Gpz, I don't think I've ever been able to turn the motor over in first gear except when bump starting. Even when bump starting, if the engine is warm, the rear tire will often just skid. I have to jump onto the seat while releasing the clutch. It's much easier in third gear. And if you are turning by hand, you will probably have to go to 6th gear to make things easier.

As Riturbo said, there is a ton of 550 info on my site. Check the carb site, especially, and of course get all of the manuals (there are several). Before doing anything with the valve cover, read the valve train warning. That will save some broken parts, hopefully.

If you play with the shifter and rock the bike back and forth, you can sometimes get the bike into second gear. After that, all of the higher gears are available.