Finally got to ride today! More questions now.

Hey all;
82 GPz750. Finally got her running good enough to take her out on the side streets today and see how she ran actually on the road, and it's pretty damn good. Finally got the vac lines all capped and deleted the one part that was recommended (per a posted pic that's all over the site). There's a squeak coming from somewhere while bike is rolling, but can't pinpoint location or describe it or anything. Will get a camera on board next time and post it to try to diagnos.

The main problem still having is cold starts. Need to use some starter fluid for that first bump. That's with the choke pulled all the way out. With the choke pushed all the way in, the bike won't even idle. It'll choke and die. Won't even turn over in that case. IF it does start, when I hit the gas, it sputters and dies hard.

With choke out and running, once it's warming up and idling pretty decent, it'll be at idle, and then slowly start going up in idle speed. But that stops once it's fully warmed. Any ideas on any of this?

Thanks!!

Sounds like your carbs are still clogged and dirty.

If with the choke off the idle creeps up you may have a vacuum leak. This may be caused by loose fitting vacuum caps on the carb holder synch ports (if your carbs have them) or by leaking carb holders.

You should check the carb holders for leaks. They will eventually develop tiny cracks in the mating surfaces between the holders and the cylinder head that can cause them to leak at idle. These cracks cannot be seen with the carb holders in place. I suggest you try the following. Get the engine warmed up and temporarily set the idle as low as possible without killing the engine (lower than 900 rpm if possible). The lower the better because with the idle very low the slides are nearly shut and the vacuum inside the carb holders is at its highest. Then spray carb cleaner around the carb holders, especially where they mate with the cylinder head and where the carbs attach to them. Carb cleaner works best for this test as it doesn't leave an oily mess with WD40 or evaporate so quickly that it is not drawn into the leaks as can happen with propane or starting fluid (ether). If the engine dies or reacts to the carb cleaner, you need to replace the carb holders. Carb holder leak related problems are noticeable at idle but generally don't have much impact when riding because the throttle is open. If you find you need to replace the carb holders soak the screws with Kroil for a couple days before attempting to remove them, and use JIS standard, NOT Phillips, screwdriver bits, and this will greatly improve the odds that you will not break or strip a carb holder fastener as so many have done. Let me know if you you need info on JIS bits, I have a good link for making your own at no cost. Ed

Thank you for the responses.

The carbs were rebuilt entirely and of course cleaned in the process. 99% sure that the carbs themselves are not the problem.

I just added all new vac caps on the carbs just today. Did the same when they were still connected as well as being capped.

I will give the test a try next time I can to see what results I get. To me that makes sense that it would cause the idle to go up, but with mine is only does that when it's warming up. Once she was at 100%, it never did the raising idle again. Seems that it would be causing an issue the whole time, not just in warmup, no?

Again, thanks!

The mating surfaces of the carb holders are rubber, so they may soften, expand, or otherwise change when they heat up, and this could cause the amount of leakage to change (if they actually are leaking). Ed

I will check the carb holders. Where can I purchase new ones of those? Only seen used.

Any ideas on the cold starts? Seems that when the choke is in, it should at least run but at high idle, not just entirely die out. Like I said, when choke is pushed in and I try to give it gas when it's trying to die, it just sputters and die.

Also, any idea where I can how the seat bolts down? I have brackets and nuts and bolts, but nothing seems to fit together.

PS... finally got the bike registered and plates!

Thanks!

david-b wrote: I will check the carb holders. Where can I purchase new ones of those? Only seen used.

Any ideas on the cold starts? Seems that when the choke is in, it should at least run but at high idle, not just entirely die out. Like I said, when choke is pushed in and I try to give it gas when it's trying to die, it just sputters and die.

Also, any idea where I can how the seat bolts down? I have brackets and nuts and bolts, but nothing seems to fit together.

PS... finally got the bike registered and plates!

Thanks!

According to Kawasaki.com the carb holders are still an "Active" part (see diagram below) so any dealer can get them for you. Partzilla lists them at $13.30 each.

find.partzilla.com/?r=t&q=16065-1132&x=11&y=11



Here's the seat diagram, but unfortunately it doesn't look like it's much help. Ed

Perfect thank you very much! I may just end ordering these anyway since they're so inexpensive.

As far as the seat, I have 27012 and 13019 (and all the bolts/washers) but it seems like those don't connect to anything either on the seat or the frame. I'll have to find some pics of how it all goes together.

Did some riding today again around the block. Started day off by changing spark plugs finally and that made a world of difference. Idle is much smoother and motor sounds healthier now.

When starting, she still didn't want to fire up on her own. I sprayed some starter fluid in and she fired right up then. And with the new plugs, great idle. No increase in idle speed or any change. When I push the choke in, she still dies out right away. So the bike will warm up all the way with no choke. Still weird with that!

I checked the boots, and didn't see any difference from spraying carb cleaner on them when warmed up.

Now I'm thinking... the previous owner hacked up the petcock so it's constant on. I installed a fuel valve between the tank and the carbs so I can turn the fuel on and off manually. Correct me if I'm wrong, but the petcock is vacuum controlled. So if while cranking, the motor produces some vac and would pump the gas. As is, the gas is just gravity fed. Does this make a difference?

Also on the bottom of the tank, whats the one nipple for the on the right side of it? Mines just open.

Have to make a clutch adjustment as I feel it's dragging some while in neutral. Will do according to the manual.
Thanks!

You are running Mikuni BS34SS carbs, are you not?
If so, go here and check the rebuild tutorial for Mikuni carbs. If they were not rebuilt using this procedure you need to start over. They are far different from the Kehiens that the rest of the Kaws use, and require an extremely thorough cleaning process to clean out all the tiny passages. Just spraying them out with carb cleaner does not work on these carbs.
And do not bother going to cycle-orings.com. They do not fit and he does not care (personal experience). You have to find your own Viton o-rings.
As a side note, the passages for your enrichment circuits (choke) are clogged. Only this procedure will clean them out. Just so you know.

That nipple is the overflow for the tank. It should have a long hose going back behind the engine in case the tank overflows.

+ 100 0n the carb clean. You should check the pilots as well as the enrichment circuit. It's been said before but with these it usually takes about three cleanings before you get it right.
You also may want to check the valve clearances. I know mine was very difficult to start when cold and then would run horribly for the first few miles. I had to blip the throttle at stop lights to keep it running. After the valve adjustment I rarely use full choke and it starts up and idles smooth at first touch. One more thing, you may want to check the jetting. If it has a 4 into 1 or a K&N these bikes will benefit from a jetting change.
Have you done a compression check?