[FONT=qdpxqc+helvetica-bold,Arial, Helvetica, sans-serif]Sierr[FONT=qdpxqc+helvetica-bold,Arial, Helvetica, sans-serif]a [/FONT]18-5180 or 18-23205 should work
a little mounting mod may be required, but should work electrically[/FONT]
Thanks to all above for suggestions and leads to coils. I will check them all out and see who has item available. Once again, thanks to all who replied both on posts and P/M
racerone,
carb was removed and cleaned. All electrical tests done according to factory manual. All within spec except for ohm meter test of coil primary side.
Motor will start and run great for approx 5 min and then it starts to miss. Miss increases as motor warms up. Oil pressure checked and is 40 psi. Tests of spark with a "smart tach" from Mac Tools shows 13K on one plug and 3K on the other.
Leads me to think coil is bad.
rcb130
Have you checked valve clearance ?---------Does spark jump a gap of 3/8" on both leads ?---Test with a 3/8" gap with motor cold and warmed up after it starts to miss.
Since this is likely a "Waste Spark" system, each plug is fired simultaneously. The required voltage for each cylinder will be different for 2 reasons...one is being fired under compression (the other not). Secondly, one is fired in reverse polarity which requires more energy.
A tight valve adjustment gets tighter as temp increases. Sometimes so much so that it drops compression. Make sure the valves aren't adjusted too tight....
It sure is a wasted spark set-up.---Both coils fire at the same time.-----Owner should see if plug wires are long enuff to switch plug wires.----Start motor and do the peak voltage reading again with motor running.
My thanks to Yegboats for finding me a coil for a spare. Compression was 150,145. Valve clearance was right on. Switched out coil and problem went with it.
thanks to all who offered suggestions.
rcb130
