FZRSupport: the FZROnline Archive

So, i noticed the new addition to the family is only running on 3 cylinders. Never a great start but hey, its not had much use in a while and its going top take a while to iron out the bugs.

The day started like this - remove panels, drain fuel.

And ended being a total strip and clean of the carbs, some reworking of the cabling, and a lot of minor corrosion removal!

Oh... and a few dozen spider remains (and a couple of living ones!) removed

PICS!










Thats gotta pinch...




And when you get this close, you have to take a piccy!






Before....


A little tweak here...




...And After!



A quick scrub of all that spottyness.


And back in they go.


And with her all back together, and the plugs cleaned, the earth points all shiny and the HT leads serviced... and she's still only firing on 3

Not sure when i'll find another day to do a little more exploration, but im guessing its electrical. I reckon it may be a faulty plug or a corroded connector somewhere, i am borrowing a laser temp gauge Monday so i should be able to work out which cylinder is the faulty one. Still, worth the effort and a day in the garage. Its a healthy step in the right direction.

Nice write up and good photos.
Those pics are SO familiar of all of mine when first purchased and stripped.
Swap over the leads and plug from the offending cylinder with the one from the same coil (wasted spark principle)
However I would state; 90% of dropped cylinders are down to carb problems.
Be very, very careful with the jet block retaining nut.Barely more than finger tight will shear the old brass.
PO knew the score; replaced X head bowl screws with cap heads.
Looks tidy and original in the the carbs off pics.
What is your location.?

A 1WG with a 3TJ swinger. After the 17" rear wheel I imagine. Nice looking bike!

Chris; it is a 600 3HE but the model with the trapezoid headlight.
It is a respected members old bike; Yamaha George.
There will be a write up on the trials and tribulations of the s/a swap; George is a stickler for documentation.
Mind he is still to pounce on the O.P for not putting his location in his profile.

Ummm... *quickly fixes location*

Plugs are coming out a little sooty so i have a minor mixture issue, and im waiting on a new set of plugs to arrive just to make sure its not a weak spark from the old ones. Ive read somewhere the HT caps are prone to breaking down too and can be tested for resistance - i'll give them a good workout while the plugs are being swapped.

Temps across the exhausts with the laser gauge are still reading differently, its cylinder 4 that's low compared to the rest.

Emulsion tubes maybe?

drlvp wrote:Ummm... *quickly fixes location*

Plugs are coming out a little sooty so i have a minor mixture issue, and im waiting on a new set of plugs to arrive just to make sure its not a weak spark from the old ones. Ive read somewhere the HT caps are prone to breaking down too and can be tested for resistance - i'll give them a good workout while the plugs are being swapped.

Temps across the exhausts with the laser gauge are still reading differently, its cylinder 4 that's low compared to the rest.

Emulsion tubes maybe?

A bright spark (pun intended) would simply swap the plug in the offending cylinder number 4 with any of the other 3 cylinders. Yeah the HT caps can fail, factory spec is 9k-11k ohms. You should also trim 1/4 inch off the 20 year old HT leads.

I'm going to replace the cables and test them later after work (if i find time!). Hopefully my new plugs will be here today too.