Kawasaki KZ 750 LTD - hesitation and missfire

I hate to say this but if you're running 'Alcool"-anything like our E-85,it's not going to run really smooth in the 3-3500 rmp range.It's just the fuel.It was made to run on the old "Regular Leaded" Gas.Ethanol burns a lot quicker and these bikes start advancing the timing in this range.Old bikes,new gas.

We don{t have anymore leaded gas in Argentina. Only regular and premium gas. Both of them have 10% of ethanol....so may be you are right, old bikes, new gas....

By the way, I did the coil relay mod with very good results...I don´t feel any hesitation, missfire or what so ever. I would recommend it to everyone with less than 12volts at the positive terminal of the coils. Nice and cheap solution.

Today I was changing the original spark plug cables with some fresh Dyna copper core and found... broken spark plug boot at cylinder number 2.




The clip that must lock the spark plug was destroyed and did not make any pressure to lock it.

So I changed it and....BANG! it seems cylinder number 2 was sometimes firing and sometimes not... or may be the spark was weak because of the bad contact. Now it is working like a charm! :silly:

hi jr

please can you advise me of this
electrical mod. i've never heard of this mod!

many thanks!

angel

steelhorseangel wrote: hi jr

please can you advise me of this
electrical mod. i've never heard of this mod!

angel

You can read the theory and details here
www.wgcarbs.com//index.php?option=com_co...sk=view&id=Itemid=89
and search here on KZR

It tends to be a tad controversial

steelhorseangel wrote: hi jr

please can you advise me of this
electrical mod. i've never heard of this mod!

many thanks!

angel

Dear Angel:

It seems that cables, plugs, key contact and kill engine contacts get "old" in bike with more than 30 years. So in every bad and old electrical connection you have a voltage drop. For example, with bike stop and key in ON position, you should measure the voltage at :

a) the battery (fully charged you should read 12,5 volts)
b) the positive terminals of the coils and ground. In the "ideal" case, you should read the same voltage as battery.

If not, then you are loosing some spark plug energy. Consider coils take those 12volts and transform it to thousands of volts... so for example a 2volt drop at the coils is a lot less thousands of volt to the spark plugs (sooty or fouled plugs). If your carbs are PERFECT, you still have problems with fouled plugs and you have a voltage drop at the coils, this is a good workaround.

However, the PRO way would be to clean and fix all the electrical connections, but it is very time consuming task. FAST way is to intall a relay directly to the battery, triggered by the positive female terminals of the cables from the kill switch.