FZR400 hard starting on cool mornings - weak coils?

[Hawker]

Hello all,

I have an '89 FZR400 that has never really been a firecracker of a starter at the best of times, and on these cool fall mornings in Saskatchewan it doesn't want to go at all. It spins over quickly, but just doesn't want to fire and catch. It has a new battery.

The normal starting procedure is full choke/no throttle, spin the starter until the engine starts to catch just a bit (10 seconds or so), and then give it a shot of throttle. If you can get it to rev up above 2000, it'll stay running no problem. It sounds and goes great once running and warmed up.

It has been suggested to me that the ignition coils on these old 80's bikes can get weak over time, and that a set of dyna coils would smarten things right up by giving a hotter spark. A friend of mine put a set on an old CBR600F2 with similar symptoms and he now swears by them. Has anyone had any experience with these coils on the FZR400?

[FasterThanUr]

It could be the valves are out of spec.the coils sound like a band aid fix to me.Do you know when if ever it has had a valve service?Could be something to look into.

[Hawker]

It could be the valves are out of spec.the coils sound like a band aid fix to me.Do you know when if ever it has had a valve service?Could be something to look into.

I have never checked the valves on this bike, so I don't know when they were last done. It has 34,000 km on it. A valve check/adjustment was on my list of winter maintenance anyway, so I guess that we will see.

[megaloxana]

yeah guarentee the valves need some adjusting.

[Hawker]

Finally getting at this job months later, and yes, you guys are right.

All of the exhaust valves are dead on spec. Cylinder 2's intake valves are dead on spec, but all of the other intake valves are way tight. 5 of those 6 are under 0.06mm (smallest feeler gauge I've got), and based upon camshaft wear I would say that 3 intake valves have no clearance, one each on cylinders 1, 3, and 4.

With greatly reduced compression when cold in three cylinders, it's no wonder that it didn't want to start. Hopefully I'll have this thing back together and running by next weekend when the new valve cover gasket comes in.

[sweekster]

Good to hear it's all coming together.

[Hawker]

It's together, and starting and running much better now. I had to adjust the clearances twice to get it right - the first adjustment assuming a zero clearance still ended up too tight. I'm down to 130 shims in 3 intake valves, and 140-160 in the rest. I hope they don't tighten right up again. There's only 33,000km on this bike, it's way too early for a valve job!

[megaloxana]

Glad it worked out for you.