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Discussion Starter · #1 ·
I'm trying to restore an '83 1100 Spectre to as close to original as I can get it. I was lucky enough to find this bike already in pretty good shape, and with used parts from eBay and new parts where available I've gotten it pretty close.
The problem I'm trying to track down now is that while it idles OK (after warming up), it runs pretty rough between about 1,500 and 2,500 RPM.
I had the carbs rebuilt by someone in the SE part of the country I can't remember anymore, and when they came back I balanced them and got the idle mixture set correctly (it took a lot of digging to find out the proper setting for the idle mixture).
I'm not sure where I should be looking. I'd welcome any suggestions.

Tire Wheel Land vehicle Fuel tank Vehicle
 

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There's no real "setting" for the idle screws, you have a starting point, and get the bike to smooth out, and then you're there. The idle circuit contributes to the total fuel used by the motorcycles. It can be a real P.I.T.A. to adjust. I would have a set of carb vacuum gauges to watch the sync, and to see what's doing what. Nice looking bike. I always though with lower bars, maybe even flat bars with risers, they would look really slick. If you ever get rear ended, that back rest will be a real horror. You could get a much loower pad for the passenger, that wouldn't drag the both of you down the road with the car. I was working at a Kawasaki dealership in 1983, and we always adised people to get the lower back rest possible. IMHO :)
 

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Discussion Starter · #3 ·
There's no real "setting" for the idle screws, you have a starting point, and get the bike to smooth out, and then you're there.
The idle mixture screws are set at the factory and access plugged. You're not supposed to mess with them. When I got them back from the rebuild I saw that the plugs had been removed, probably long before I sent them off. Because you're not supposed to mess with them there's little (i.e., no) information on adjusting them. I saw numerous posts recommending starting at ~4 turns. I tried that, but the problem is with 4 carbs it's really difficult to tell any difference tweaking one of them. It ran "OK", but the choke was driving me crazy - once the bike got started it would immediately rev to ~4K RPM, but if you reduced the choke to compensate the bike would die.
I finally found a note, I think in a KZ1100 shop manual (the same basic bike was also used as a "cruiser" with wrap-around fairing - with radio/speakers - and hard bags) that said to set the idle mixture adjustment at 1-1/4 turns. I did that, and it made a HUGE difference. I tried minor adjustments, but again, with 4 carbs,.... I left them at 1-1/4 turns.
Balancing the carbs with the idle screws is something entirely different. I have a homemade jig to watch the vacuum levels, and it's not that difficult.
I'm doing this labor of love because I had one of these that I bought new back in '83 (mine was an '82, very minor differences) that I really loved. It came straight from the dealer with a KG sissy bar/luggage rack. I was extremely lucky to find a period correct KG sissy bar/luggage rack that's almost identical to what my '82 had. It was pretty rusty, but cleaned up nicely. The only difference is that I this one won't fit with the rear grab bar on and I know my original had both. The tall backrest was ideal for strapping things like backpacks, sleeping bags, etc., to.

As an aside, there's a very small red switch on the left control cluster, next to the horn/turn signal/high beam switches. I can't figure out what it's for :-( If anyone has any ideas, let me know.
 

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Those idle screw plug screws were a government requirement. We had a bag of the at the shop, to put back in after popping them out. A spark plug reading at idle after runing will tell you if the bike is rich or lean. The reason I say use sync gauges is in the event that there is an rpm change, it's easier tosee than hear. I usually lean the bike, the go back a half or quarter turn back to rich to make the bike right. 1 and 1/4 turn is a good starting point. K and G made a back rest that came up to the small of your back. I usually mounted a tank bag on the rack. I made my own back pad for my passenger, it's only 6" inches tall. Your bike sounds like your hitting a lean spot. The bikes made in those years were very cold blooded. You could raise the needles on the CV Carbs one notch. The little enrichment will give you much needed fuel. I had to do that for my GS750ES '83, and it has no flat spots at all. I believe at 1500 your off the idle circuit. I try raising the needles one notch (if the carb needles allow for that) and see what happens. It sounds from what your writing a lean condition exist, raising the needle will give you more fuel and probably take care of the rough spot, that or fatten the idle screws all the same amount of turns, or partial turns. . IMHO. :)
 

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Discussion Starter · #5 ·
Thanks. I may try adjusting the idle mixture. I could try raising the needles, but that would entail taking the carbs off the bike and taking them apart, which is a PITA (but still something I should do, just to check that the the rebuild put them back right.) The 1-1/4 turns was indeed from a shop manual for the KZ1000/KZ1100 - the 1100 series were covered as an appendix, and had fuel injectors, so it specifically referred to the KZ1000. But it's the same carbs. And the note was region-related - the US was N/A, but for Canada and all other regions it was 1-1/4 turns.
I'll probably get it back on the lift and check the timing advance first. I'd need to do that before messing with the carbs anyway.

As an aside, there's a very small red switch on the left control cluster, next to the horn/turn signal/high beam switches. I can't figure out what it's for :-( If anyone has any ideas, let me know.
I figured out what this was. This is the emergency flasher switch. So I have either a blown fuse to find or a flasher relay to replace.
 

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That bike is too old to be fuel injected. They are probably CV carbs. If you let the bike idle till it's nice and hot, then take out a spark plug, the color of the plug will tell you if it is too rich or too lean. It should be a tannish color, but very light tan. It shouldn't be dark at all, that would indicate rich, or oil coming from somewhere. ;)

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Love the plug chart. I have never heard of doing a plug read at idle. Do you need to start with new plugs? Will running it at speed then letting it idle for an extended time invalidate the readings.
 

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Wow, that bike was really ahead of it's time. I remember them being finished off so well. I learn something new every day! That's why a manual, or checking out for yourself is best. Thanks!

What does the D.F.I. do? My 1973 Mercedes 450SL fuel injection shortens or lengthens the length of the injector spray, it is port injected. It does nothing else. It even has a dial with a clicker built in so you can "lean" or "enrich" the intake by lengthening the spray duration. The controller for these cars is located in the upper passenger foot well, if I remember correctly, counterclockwise shortens the length of the spray. It uses 4 points in the distributor to send the signal the the control box. It's mounted to the side of the distributor with two bolts. ;)
 

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That is so weird. Partzilla shows the 1982 KZ1000 and 1100 to have carbs.

Found some interesting info in an older thread.
 

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That is so weird. Partzilla shows the 1982 KZ1000 and 1100 to have carbs.

Found some interesting info in an older thread.

Kind of surprised the heck out of me too. ;)
 
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