cam timing-compression or exhaust stoke

Been struggling with rebuild(1st time)top end. Set cams 3 times now . Using Clymer manual backfires every time on start up wouldn't start. Found problem with coil wiring info on manual. When replacing valve cover(page 74)says green coil wire goes to left coil (WRONG) finally found pdf manual online to correct the problem. Started right up. .Still not sure if I have the cam set up right. Compression stroke or exaust? Will it even run if the timing is 180 degess off? Any help?

Cams can't be 180 off, to see for yourself take the valve cover off with the timing marks on the rotor at tdc. Observe the position of the cam, turn the crank one revolution to tdc and look at the cams again. Now they are technically 180 out, but if you turn the crank once more they'll be back in time again. Cams turn once for every two revolutions of the crank.

If it's running good and has good compression, then the cams are probably right.

It's easy to check though, and there is that "peace of mind" thing.

Hey thanks for the quick reply. I have had the cams off several times and have turned the crank as well. Before I reset the timing again, I'd like to know by looking into the #4 or #1 piston with the plug removed can you observe the valve open and close? Which is open on compression stroke the front or rear?

Neither one should be open during the compression stroke, the intake closes after bottom dead center on the intake/compression stroke, then the exhaust opens at the end of the power stroke (before bottom dead center) and closes after top dead center on the exhaust/intake stroke.

Any sure way of knowing if I have the right set up other than compression check? Don't have a reliable guage right now. Will the bike run if I have the cams 180 degree off? Thanks for your knowledge on this issue.

As far as I know, everyone that got the cams on a KZ motor out of time bent valves.

Why don't you take the valve cover off and visually verify the correct timing?

If the cams are 180 out, just rotate the motor one revolution and the cams will be in time.

Think about it, cams turn at 1/2 engine rpm, so every other revolution they will be 180 out.

They can be out any other number though, just not 180.

How will I know if the valves are bent ? Will it lock up? I forgot to tell you its a 1981 kz 1000 ltd. The manual says line the exhaust arrow to front of cylinder head and the IN arrow to the rear of cylinder head and timing is correct.

If the valves are bent it either won't start at all, or it will run really bad. And you'll have tons of clearance between the valve buckets and the cams. It won't lock up, the valves generally bend due to hitting each other. I know of people that bent all the valves on a 750 four by bench shimming the valves with the head laying flat on a bench.

have you taken the ignition timing cover off to check for 1,4 tdc?

brodavid wrote: Been struggling with rebuild(1st time)top end. Set cams 3 times now . Using Clymer manual backfires every time on start up wouldn't start. Found problem with coil wiring info on manual. When replacing valve cover(page 74)says green coil wire goes to left coil (WRONG) finally found pdf manual online to correct the problem. Started right up. .Still not sure if I have the cam set up right. Compression stroke or exaust? Will it even run if the timing is 180 degess off? Any help?

Is this the 1981 kz 1000 ltd k-1 mentioned in an earlier thread?

Including information about bike year and model is helpful to viewers and usually elicits better responses.
It's easy to put the information in your signature where it shows in all posted messages, past and future.
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Patton wrote:

brodavid wrote: Been struggling with rebuild(1st time)top end. Set cams 3 times now . Using Clymer manual backfires every time on start up wouldn't start. Found problem with coil wiring info on manual. When replacing valve cover(page 74)says green coil wire goes to left coil (WRONG) finally found pdf manual online to correct the problem. Started right up. .Still not sure if I have the cam set up right. Compression stroke or exaust? Will it even run if the timing is 180 degess off? Any help?

Is this the 1981 kz 1000 ltd k-1 mentioned in an earlier thread?

Including information about bike year and model is helpful to viewers and usually elicits better responses.
It's easy to put the information in your signature where it shows in all posted messages, past and future.
And may be changed whenever and as often as desired.
If wanting a signature showing information about the bike in posted messages, it's easy to do. Here's how:

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Good Fortune!

what make/year/model it is a hassle to ask everyone so put it in your signature. forgive me as I am a man of few words.

Ok got everything back together with top end clean up and new gaskets. Bike starts ok, but vibrates and had to turn idle screw way up to get it to stay running. Lacks power rpms wont go over 4000 on normal throttle response. My compression gauge is broken (It won't lock on high pressure) but it reads about 90psi and drops back down. Didn't have time to check all cylinders . Does it sound like compression problem. I reshimmed valves,replaced one ring and cleaned all carbon deposits on pistons and valves. Set cam timimg acorrding to specs. Any help much appreciated.1981 kz 1000 ltd k1