77 KZ1000 fouling plugs, missing......

Last year I raised, or attempted to, my 77 KZ1000 from the grave and CAN NOT get the bike to run worth a flip. To make a long story short I am having trouble with getting the bike to run without fouling plugs, missing-sputtering, and generally not running worth a @$%%. I rebuilt the carbs, installed Emgo filters, installed a Vance Hines 4 into 1 header, replaced intermittent coils with a set of Dyna Coils and then took it to a shop whose owner is suppose to be a KZ Guru. He installed 120 mains and he supposedly tweeked it and I couldn't ride it over 50 miles without the plugs fouling. I replaced the mains with stock 107.5's, which I know now is probably too small and I've consulted the same mechanic and get blown off everytime. I live in relatively a small town where very few trusted bike mechanics exist. Where else to turn now but here. I'm completely frustrated, sunk a ton of money into the bike and I'd Love to ride it with a grin instead of try'n to limp it back to the house. And also have a problem with cylinders 2&3 not firing for about 3-5 minutes after the bike is started and cylinders 1&4 are keeping it turning over. I have checked for fire prior to starting the bike, on 2&3, and it's there. I realize that by downsizing the mains the air needs adjustment but I'm sure with the combo of air filters and header the 107.5's are too small. Anyone have suggestions, even a good place to start as far as pairing up the mains/air filters/header combo. Or do I need to focus on the pilot jets at this point? Thanks as always for the help.

I had the same problem on my 78. I spent a ton of cash and cursed the bike until I found out the compression was low. Check it out and do a leak down test.

tennacnightman wrote:

Last year I raised, or attempted to, my 77 KZ1000 from the grave and CAN NOT get the bike to run worth a flip. To make a long story short I am having trouble with getting the bike to run without fouling plugs, missing-sputtering, and generally not running worth a @$%%. I rebuilt the carbs, installed Emgo filters, installed a Vance Hines 4 into 1 header, replaced intermittent coils with a set of Dyna Coils and then took it to a shop whose owner is suppose to be a KZ Guru. He installed 120 mains and he supposedly tweeked it and I couldn't ride it over 50 miles without the plugs fouling. I replaced the mains with stock 107.5's, which I know now is probably too small and I've consulted the same mechanic and get blown off everytime. I live in relatively a small town where very few trusted bike mechanics exist. Where else to turn now but here. I'm completely frustrated, sunk a ton of money into the bike and I'd Love to ride it with a grin instead of try'n to limp it back to the house. And also have a problem with cylinders 2&3 not firing for about 3-5 minutes after the bike is started and cylinders 1&4 are keeping it turning over. I have checked for fire prior to starting the bike, on 2&3, and it's there. I realize that by downsizing the mains the air needs adjustment but I'm sure with the combo of air filters and header the 107.5's are too small. Anyone have suggestions, even a good place to start as far as pairing up the mains/air filters/header combo. Or do I need to focus on the pilot jets at this point? Thanks as always for the help.

You may be fouling plugs from oil seepage. Might be valve guide seals. I agree, first thing check the compression cold/hot. Check the plugs for oil, see if there is a bit of blue smoke on start up that goes away: that's the sign of bad valve seals.

Yep, valve stem seals. When were the last time they were changed? Low compression could contribute too.....chris3

are the plugs oil fouled or gas?

also have you checked the voltage to the new coils, also check the charging system to make sure its charging

tennacnightman wrote:

And also have a problem with cylinders 2&3 not firing for about 3-5 minutes after the bike is started and cylinders 1&4 are keeping it turning over. I have checked for fire prior to starting the bike, on 2&3, and it's there.

It could be those plugs are oil fouled and they need to have gas run on them to wash them enough to fire.

Try cleaning the plugs and then starting it and see if it runs good. That will tell you if it's the plugs.

BTW, mine was fouling plugs so bad I had to carry a spare set and a plug wrench for a while when it wouldn't start.. It was oil leaking down from the valve seals.

tennacnightman wrote:

Last year I raised, or attempted to, my 77 KZ1000 from the grave and CAN NOT get the bike to run worth a flip. To make a long story short I am having trouble with getting the bike to run without fouling plugs, missing-sputtering, and generally not running worth a @$%%. I rebuilt the carbs, installed Emgo filters, installed a Vance Hines 4 into 1 header, replaced intermittent coils with a set of Dyna Coils and then took it to a shop whose owner is suppose to be a KZ Guru. He installed 120 mains and he supposedly tweeked it and I couldn't ride it over 50 miles without the plugs fouling. I replaced the mains with stock 107.5's, which I know now is probably too small and I've consulted the same mechanic and get blown off everytime. I live in relatively a small town where very few trusted bike mechanics exist. Where else to turn now but here. I'm completely frustrated, sunk a ton of money into the bike and I'd Love to ride it with a grin instead of try'n to limp it back to the house. And also have a problem with cylinders 2&3 not firing for about 3-5 minutes after the bike is started and cylinders 1&4 are keeping it turning over. I have checked for fire prior to starting the bike, on 2&3, and it's there. I realize that by downsizing the mains the air needs adjustment but I'm sure with the combo of air filters and header the 107.5's are too small. Anyone have suggestions, even a good place to start as far as pairing up the mains/air filters/header combo. Or do I need to focus on the pilot jets at this point? Thanks as always for the help.

It sounds like me trying to rejet the new headers not realizing mine needed a valve job and was just running crappy in general.

I would recommend:

1) Do a cold/hot compression test on each cylinder.

2) Check the odometer.... if it's been 15k miles or more since the last valve job, valve seals are definitely suspect.

3) Check plugs for oil. If they are oil fouling, get a top end overhaul.

Post edited by: bountyhunter, at: 2008/01/21 16:47

I'm assuming that they are gas fouled. I can remove the plugs and they have a heavy build up of dry black carbon. Other responses I've received recommend a valve job done on the motor. The bike has around 28K miles and as far as I know there has never been a valve job done on the bike. When I put the bike up, about 20 years ago, it ran great. I realize one sitting for such a long time that it is hard on a motor. I suppose there could be many possibles with trying bring this bike back to life after sitting for so long. BTW no oily residue on the plugs at all. Thanks.

As far as I know the valve seals have never been changed. I bought the bike in 85 and have put about 5K on it myself. It now has about 28K on the motor. Hopefully I'm not looking at a full overhaul. Already spoke the mechanic/owner, I mentioned earlier, and he said they usually bore the cylinders out slightly and go from there. Quit expensive but sure would like to have this bike running great. What's cool about it is that about everytime I stop at a fuel station I usually count on spending sometime there because folks are wanting to know about the bike. Not that it's a exceptional bike but it's reputation in it's day. A good conversation piece. Thanks for the input. Any other advice is welcomed.

Post edited by: tennacnightman, at: 2008/01/24 13:47

Besides high mileage, time is your enemy. Motors that have sat for a long time tend to have the various rubber bits deteriorate or get very hard. Things you might consider are:

(1) Lap the valves
(2) Replace valve stem seals
(3) Replace all the rubber pieces associated with the cam chain/adjuster
(4) Check the stretch on your cam chain
(5) Check the tolerances on your cylinder bores

All this should be done after you check compression

tennacnightman wrote:

I'm assuming that they are gas fouled. I can remove the plugs and they have a heavy build up of dry black carbon. Other responses I've received recommend a valve job done on the motor. The bike has around 28K miles and as far as I know there has never been a valve job done on the bike. When I put the bike up, about 20 years ago, it ran great. I realize one sitting for such a long time that it is hard on a motor. I suppose there could be many possibles with trying bring this bike back to life after sitting for so long. BTW no oily residue on the plugs at all. Thanks.

Before addressing carbs, would assure: compression tests okay; valve clearances set to specs; ignition timing close as possible under the circumstances; fat blue spark. As known, even perfect carbs with perfect fuel cannot compensate for a problem with compression or ignition.

Then to carbs: Too high float level setting can cause excessively rich mixture resulting in quick plug fouling. If not already done, would perform the quick easy clear plastic tube test. Next guess would be to assure clean clear air passages in the pilot circuits.

Good Luck!

tennacnightman wrote:

As far as I know the valve seals have never been changed. I bought the bike in 85 and have put about 5K on it myself. It now has about 28K on the motor. Hopefully I'm not looking at a full overhaul. Already spoke the mechanic/owner, I mentioned earlier, and he said they usually bore the cylinders out slightly and go from there. Quit expensive but sure would like to have this bike running great. What's cool about it is that about everytime I stop at a fuel station I usually count on spending sometime there because folks are wanting to know about the bike. Not that it's a exceptional bike but it's reputation in it's day. A good conversation piece. Thanks for the input. Any other advice is welcomed.<br><br>Post edited by: tennacnightman, at: 2008/01/24 13:47

At 28k miles, I sincerely doubt there is enough cylinder wear to require boring. If it has never had a valve job, I would be shocked if it did NOT need one..... and if it is over 20 years old on the original rubber valve seals, the cahnces are they re hosed.

Check cold/hot compression and it will tell you if you need a valve job.

tennacnightman wrote:

I rebuilt the carbs, installed Emgo filters, installed a Vance Hines 4 into 1 header, replaced intermittent coils with a set of Dyna Coils and then took it to a shop whose owner is suppose to be a KZ Guru. He installed 120 mains and he supposedly tweeked it and I couldn't ride it over 50 miles without the plugs fouling.

Some thoughts:

Are the "emgo filters" pods or do you have the stock airbox? From what I read, pods are the spawn of Satan and can never be jetted properly on these bikes. If you have the stock airbox, you might want to try it.

If you are running severely rich in normal riding, it probably is not the fault of the main jets which control the mix almost entirely at wide open throttle and high RPM.

In "normal" riding the needles prety much control most of the action. Are the needles set too rich maybe?

Post edited by: bountyhunter, at: 2008/01/24 16:25