Very poor running

Hi,

I have a 1981 KZ1100A trike with rather predictably a Zed 1100 engine sat in it. This engine has just had new valve seats, been re-shimmed and has had a top end rebuild. It is making between 125 and 130psi across all barrels with a very slow starter.

I can get it to run and sometimes it will run ok ish for a few seconds but seems to have a problem predominantly on #2. If you have the filters off and fire it off you can see a little vapour blowback on all the carbs but on #2 it is much more visible. #2 does not seem to run well and if you hold your hjand over the 1 and 2 exhaust then you can feel a pulse from it which suggests it is not firing well and the one from 3 and 4 is very different, nice and smooth gas flow.

I put a strobe light on the leads and on #2 you can see an intermittent pulse. I have changed coils to my spare pair, no difference, changed the pickup and no difference, out of desperation I changed plug leads even though they are only 1 hours running old as well as the plugs for a set of iridiums but still the same. I even put my old bank of carbs on off my spare engine and still the same. I'm at an absolute loss as to what to look at, the only electronic components I haven't swapped is the ignite and rectifier but i'd be surprised if it is those.

I've exhausted everything I know and am right now just clutching at straws which I know is a bad way to go about things so any pointers would be most gratefully received.

Thanks

Simon

Using a stronger Honda starter motor in a Kawasaki

Buda from the www.kzrider.com forum wrote:

Will not turn the engine over....10.25 10 1 comp 1170 cc......took starter out and ran it with a battery....the starter spins strong but starts to squeal after a second.....also the shaft has a lot of play side to side. Bad starter I’m guessing What do you guys think?

Took the starter apart.....the bushing on the drive end is cracked

MFolks Wrote:
For a stronger starter motor, read this:

Using a Honda Mitsuba SM-220 Starter in the Kz (copied from the KZ rider website)

The CB F's used 2 different starters. Look for the one marked .8kw. They also have one that is .7kw. This owner noticed a difference when he installed his. He read that you can remove the outer housing, and rotate it. this will re-align the outer power terminal, to a better location. if you don’t do this, you will need to grind some metal from the chain cover to gain clearance. Also install a heavier gauge wire to the starter , I’d recommend 6 AWG(American Wire Gauge) welding cable with the correct terminal ends to match the treaded studs for the solenoid and starter motor. Don’t forget the cable from the battery to the solenoid.

The stock KZ starter is .6kw in size

www.stockers.com/index.php?dt=HS-29 (Mitsuba SM-220)

Buda Wrote:
Thanks MFolks, Just ordered the rebuild kit before I read your post....If that doesn't work out I'll give the Honda starter a shot.

Got a the Honda starter MFolks recommended (SM 220 12 volt 0.8 KW) on ebay...hell of a difference.....Turns over like the plugs are missing....I'm sure the new battery doesn't hurt, but its a hell of a difference.


Are you using resistor sparkplugs, along with resistive sparkplug wires? If the plugs have an "R" in the number, they are resistors. Try another brand of plug, I've been reading about problems with the U.S. made NGK's. Maybe a set of Denso W24-ESU's or comparable Accels might make the engine run.

Sparkplug Cross Index
www.gadgetjq.com/spark_plug_cross_reference_motorcycle.htm
www.sparkplug-crossreference.com/convert/NGK_PN/B8ES/
www.globaldenso.com/en/products/aftermarket/plug/

I read holding your hand over the exhaust, did you mean Intake? Or do you have no exhaust hooked up?
Running Cv Bs34 carbs still? No filters/ airbox will make it lean. So will vacuum leaks.
When the valve work was done, was the shims changed, clearances set to spec?
Cam timing correct?
Are you sure the spark plug wires are on correctly, 1-4/ 2-3, fire as pairs wasted spark ignition.

Hi guys,

Thanks for the starter info, will definitely look into that, much appreciated.

The head work was done about a week ago and the shims were changed at that time by the guy who did the head too.

I do not believe I have resistive caps and resistive plugs, I have the black cap NGK caps whereas I believed that they were non resistive but am happy to be corrected. The coils are wired up 1-4 and 2-3 as I believe they need to be.

I have the exhaust hooked up but from standing by the side of it I can put my hand over the exhaust pipes easily to feel for any differential in warmth when running, pots 3 and 4 definitely run warmer than 1 and 2 but id expect that given the symptoms.

Currently I have no filters on it while i'm trying to sort it and if I put full choke on then it rarely wants to know however if I put my hand and forearm over the carb intakes then as soon as I release my arm then it will kick and normally go however there is a lot of fuel that comes out the back of #2. It is running the mikunis as standard.

Cam timing was set allegedly by a mechanic and when I checked it was as per the manual. Now its proving a pain the guy won't even answer the phone to me which makes me doubt everything he has touched......

If you don't have one, download a copy of the Factory manual here: www.kawiworld.com/index.php?option=com_c...icle&id=77&Itemid=99
Carbs will Pop back through intake when lean. This is common when filters/ airbox is not in place. Have you or the Mechanic been through the carbs? The Pilot circuit and transitions circuit must be perfectly clean. Float level set on the bench, still needs a wet check with the Clear Tube Method. Attach a clear tube to the drain and with the drain screw open hold the tube up along side the carb body. Fuel will show in this basic sight gauge the wet level. It should be the same on all 4, and about 3mm below the gasket surface.
If you think the guy was not that great, I'd start with a double check of the Head Torque. Then Valve Clearances/ Cam Timing. Make sure the basics there are good.