New to KZ's, lots of questions

Hi guys. I've come into possession of a 79 KZ1000 shaft that's not quite sorted out. This definitely seems the place for answers (I've tried using the search feature.)
I don't have a manual yet but its in route.

The bike has a 4 into 1 and pod's installed. I also have (i think) a stock airbox. I've been told the bike has a new top end. I recently put in new plugs and have a bright blue spark in all cylinders.

The bike will almost start with no choke. If I give it full choke it fires up immediately but runs at 4000rpm. When I drop the choke it rough idles at a hair over 1000rpm. I say rough idle because I haven't gotten number 3 to fire yet. I'm thinking that getting 3 to fire will even out the idle significantly. There's also a little random popping from one of the pods.

Last night I pulled the carb rack and dropped the float bowl on #3. There was lots of fuel in the float but without a book I wasn't sure if the level was right. I pulled the pilot and the main jet. Hit them with carb cleaner, blew them out. There had been a little gummy on the pilot so I was hoping that was it. Put it all back together and fired it up.

#3 is still not firing. I let it idle about 2 minutes last night while trying to figure out what was up with #3. For no reason I could determine, it jumped up to a 4000rpm idle again. I killed the engine and here I sit.

I'm new to KZ's and mikuni's. But I think this is where I stand:

1) Popping might be due to valve clearance. I've ordered a gasket from Z1 and plan on checking them when it shows up.
2) Do a total carb break down and cleaning? The PO told me it had been recently done but I'm beginning to suspect the jets were just changed (old float bowl gasket.) Should I do them all or just 3? I don't feel like spending close to $100 for 4 rebuild kits.

I'm fairly handy but don't have any specialized tools. I'm going overseas at the end of the year and the bike will sit for a year while I'm gone. I was really hoping to get some riding done this season instead of wrenching.
Sorry my first post is so long. I'd really appreciate what ever advice ya'll can give.

Forgot something. The carb is a VM28. When I pulled the jets the pilot had 135 stamped on the bottom and the main had 15. I assume those are jet sizes. Does that sound about right?

welcome...those shafts are one tough bike.....strange that it wont fire on #3 ...but man you are doing all the right steps imo to track it....these old girls can be fickle and hide their probs for the new owner at first...but you sure do ask the right questions and are doing smart fixes,,,the manual will get you forward and someone will chime in smarter than me......good luck and welcome bro...peace craig

HAve you tried a new spark plug in #3 yet?
I have a 79 E and from time to time #4 will become oil fouled. Pull the plug and check it.

I would replace all 4 plugs while you are at it. NGK B8ES work for me.

My bike ofen idles at 3500-4000 rpms on start up on full choke, but afer 20 seconds I push that choke down to 1/2 for a couple of mins while I get me helmet and jacket on. Then kill the choke and she should run at 1100 rpm's.

That bike is a beast and has plenty of power to get you going hella quick (for a 30 year old machine) if you want. No trouble finding power on the highway.

I wish it had an extra gear for cruising.

Take the revs all the way up to have a really spirited ride.

Good Luck

KRB)

Thanks guys.
It has 4 brand new plugs. NGK B8ES. Gapped to .29 Good spark on 3. My gut tells me it's carb probs.

Anybody got any ideas on why it would suddenly jump up to a 4000rpm idle? Seems to me like a jetting issue somewhere. It's like the main kicked in when it should only be running on pilot. But it happened with the throttle closed and I assume the carb slide and needle jet closed.

Yeah I'm really looking forward to letting this thing rip but I've had it a week and it hasn't left the garage. 80deg and sunny, thank God I have another bike.

Spark on all four, random pod popping, #3 won't fire...
Check #3's carb to head boot for cracks/leaks?

Will do that. Isn't the normal method to spray wd40 around the intake boot and listen for changes in engine? Does that method work when there's no combustion in a cylinder? The boots look brand new, they have vacuum ports on them for synchronizing. The ports are covered with rubber caps. I'll check.

Are the boots pretty tough? By that I mean can they withstand taking the carbs on/off many times or are they prone to wear and cracking?

I'm really hoping the manual is waiting for me in the mail when I get home. Thanks ya'll.

Those boots are real tough! I've had mine off 9874 times!!! The vac. ports on mine are not plugged ,2 hoses go to top vaccum vent filter. But, I think you've got something plugging your #3 carb.!!CLEAN again.Good luck.


Later,Boots

Vacuum vent filter?? Am I missing something? All 4 of the intake boots (between carbs and cylinders) have a brass vacuum port. I assumed those are for synchronizing the carbs. All 4 of mine are covered with a rubber cap. Is this not right?

I guess I should also mention that I have an inline petcock and fuel filter. Not using a vacuum petcock. If that matters.

Thanks.

Mortarmanmike wrote:

...All 4 of the intake boots (between carbs and cylinders) have a brass vacuum port....

Some quad-carb racks have a 5th vac nipple for vac petcock, which would also be capped where manual petcock is fitted.

Some models use 2 of the 4 (or 5) vac nipples incident to an emission control system (many of which systems have been removed with then unused vac nipples being capped).

Good Luck!

[Click on image to enhance view]

I really don't think it matters that yours is blocked off.Like I said I would clean again. You never know there could be that tiny bit screwing you up!!!It don't take much! Try putting some sea foam in your tank, run that through your carbs. How long has it been sitting?They do funny things after sitting! Believe me I've been chasing bugs all my life. LOL No really, carbs. act funny after sitting.
Good luck!

Later, Boots

Thanks guys.
Boots, the tank has been creamed (sp?) and the engine just recently rebuilt. I'm assuming the bike was a basketcase before I bought it. So far this is my plan of attack:

1) recheck the plug. It's brand new but who knows might still be fouled. Prob swap #3 and #4 to see it the problem migrates.

2) Check for any intake leaks. Does the WD40 method still work if a cyclinders not firing at all? I've used it with a poorly running cylinder but not one that was dead.

3) check the float bowl level with the carb on the bike. I read how to do that on another thread. I'll also replace the inline fuel filter just to be sure.

4) when my manual and gasket arrives, check the valve clearance.

5) if all the above fails, I'll pull the carb and do an entire rebuild. That's the only way to know it's done right. That lemon juice method looks interesting.

6) if I actually get all 4 cylinders running, I'll start trying to read the plugs to see if it's jetted properly.

Back to one of my initial questions. With the bike idling on 3 cylinders, does anybody have any idea what would cause it to suddenly rev and idle at 4000rpm. Besides intake leak which I'll check later.

Thanks ya'll. I've already learned a great deal about these mikunis on here. Keep the shiney side up.