Logo
FULL SITE MENU

9.5HP, what's that noise?

Eeee... that's the last thing I wanted to do. Does it explain the hesitation though? other than when I adjust the throttle, the engine runs fine 99% of the time.
 
Check the gear oil.-----Check the plug wires where they bend 90 degrees coming down from the magneto plate.----Could be shorting to ground.------Could have an ignition coil that is cracked / shorting to ground.-----You have to lift the coil off the plate to find that " burn through " of the coil.-----And does spark jump a gap of 5/16" on both leads , yes or no ?
 
sailor88 said:
Eeee... that's the last thing I wanted to do. Does it explain the hesitation though? other than when I adjust the throttle, the engine runs fine 99% of the time.
Click to expand...

Id say an ignition miss too but worth trying new plugs before pulling the flywheel (if/ when you do make sure you use the correct type of puller and to correctly torque the retaining nut when refitting.

Much info on the 9.5 here http://leeroysramblings.com/OMC_9.5.htm
 
Gear oil just replaced, plugs are also brand new NGK, I guess it's time to pull the flywheel? But I am just confused why this happens only when I change throttle, otherwise it runs as smooth as silk.
 
"And does spark jump a gap of 5/16" on both leads" Sorry racerone, I don't fully understand this question, too many jargons, would you mind explain a little more in detail?
 
sailor88 said:
"And does spark jump a gap of 5/16" on both leads" Sorry racerone, I don't fully understand this question, too many jargons, would you mind explain a little more in detail?
Click to expand...


What Racerone is asking is whether or not you can get a spark from each of the plug leads which will jump an air gap of 5/16". You could invest a few $ in an adjustable gap spark tester or improvise something if you cannot buy, borrow or steal one.

A couple of nails though a piece of dry wood with their pointed ends bent over to leave a 5/16" gap with the plug leads connected, in turn, to one nail and the other nail grounded to the powerhead would enable you to answer the question.

If both leads will give a spark that jumps the 5/16" gap it suggests all is well with the coils, points, and condensers. If not then off with the flywheel and investigate the reasons why not.
 
The sparkplug has nothing to do with this test !---The sparkplug is not used for this test.------The ignition system was designed / built at some expense to develop up to 28,000 volts.-----You need to see if it can do that today.-----It should be able to jump a gap of 5/16" on a test device with a snap you can hear,.-----Laying the plugs on the block is NOT a good test for maximum output of the magneto.
 
sailor88 said:
Use something like this?

https://www.amazon.com/ABN-Inline-S...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
Click to expand...

sailor88 said:
Are the gap adjustable on these tester? How do I know it is 5/16"?
Click to expand...

racerone said:
You adjust the gap till it measures 8 mm.
Click to expand...

The tester in Sailor88's link is not the adjustable gap type. It will show whether or not a plug is sparking but does not test the strength of the spark

This is the adjustable type : Quite obvious how to adjust it I think

61M3xcrppeL._AC_UL160_SR160,160_.jpg

https://www.amazon.com/Deal】OriGlam...PQNWA6SW11H&psc=1&refRID=GJTJXAFZKPQNWA6SW11H
 
Last edited:
OK, the spark plug tester arrived. No it wont produce a spark with 5/16" gap, the widest gap it can produce spark is about 3/16", So what's the next step? Take the flywheel off?
 
Back
Top