Mercury 110 9.8hp no spark

[dave-bernard]

like I said the white insulators at the points usually go bad.!!!!!!! look at my earlier post.

• This reply was modified 4 years, 1 month ago by Mumbles.

[Mumbles]

Two quotes from another site:

Re: Mercury 9.8 hp weak spark

Before going out a buying a stator assembly, start checking each component out throughly. Is the resistance the same on both coils? Are the plug wires and ends unbroken and free of corrosion(and the wiring from the pickup coils) Are the points gapped and timed correctly?… You know peice by piece, one step at a time. I highly doubt your stator is bad as they are bulletproof ,however…

Re: Mercury 9.8 hp weak spark

John <br />That model has 2 white plastic insulating blocks that the points wire goes through at the bolt.<br />These crack and can be very hard to see the cracks.(shows up more like carbon tracks)<br />The voltage will track to ground from these, I would advise you to replace these anyway.<br />Have seen alot of guys change stators and the only problem was the blocks.

[outbdnut2]

If you do need a stator, try to find a used one. A new one can cost more than the motor is worth. An after market CDI stator goes for around $350.00, so check everything else carefully first.
Dave

[Greenthumbed]

Hi there,

This is my first post on the forum so hello to you all!
This thread has been very informative for me. I had my 71’ Mercury 110 in the shop and they told me the stator was shot and the parts were not available. I felt that they only put a half hearted attempt at diagnosing the issue. I decided to take a look into it myself and discovered that the insulator blocks are in fact cracked and need replacing.
Does anyone know where to find these parts in Canada?

thanks,

Chad

[crosbyman]

a cooperative Merc Dealer should help you     also try amazon with the part #

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[Fbnlny]

Hello guys,

as this thread fits the topic, I hoped someone here could help me.

I am working on a 1971 Mercury 7.5 with S/N 31xxxxx.

I am currently waiting for new insulator blocks to arrive, as the spark is somewhat unreliable, so I tested everything else… When I performed the stator-resistance test, I got a weird value: no cont. with positive to green lead, as it is supposed to be. But a couble of megaohms if I switch the leads, instead of a 20-50 kiloohms.

Now what I find weird, when disconnecting the points and tapping the coils to ground, the plugs arc every single time and I have bright blue spark. The test tells me, that the stator is toast, though it still fires the plugs just fine. Do you know if the stator is broken or still usable?

Thank you

Fabi

[seakaye12]

I find that the CDI troubleshooting guide in conjunction with the specs published in the Mercury shop manual helps me a lot.

Yours is the green stator?  Mercury #336-3996A7?  If so;  according to the CDI troubleshooting guide that I attached….that the test you are making with tapping the coils to ground….seems to point to an issue with the Maker Points, the insulation block or the associated wiring?

I hope so….because as I’m sure you have discovered….those stators do not come cheap.

Do you have the Mercury Manual with the Specs for all the components?  Some of the tests require a DVA Meter.

[crosbyman]

https://wrcoutboards.org/wp-content/uploads/2021/02/The-Phase-Maker-CDI.pdf

 

 

phase make info

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[Fbnlny]

Thank you for your replies!

Yes it is the green stator #3996A7. Unfortunately the only CDI retailer in my area wants 45 dollars for a set of two insulators and delivery time is unknown. I have tried insulating the screws through the insulating blocks with heatshrink tubing. And replaced all the points wiring.

The only manual I have is the Clymers shop manual and that doesn’t tell me much more.

If I look at the PDF from crosbyman, I suppose using a modern multimeter to perform the test will yield different resistances, as the current through and therefore the applied voltage to the varistor is much lower than from an old analog meter, so I’d expect a higher resistance reading, fingers crossed…

I also had to sand the points, as they were heavily pitted, could their surface be too rough now? (New set is 100 dollars…)

 

 

[crosbyman]

points…. see #235134   from D.Bernard…points will look real bad BUT that is how they are supposed to be.

if you think they are an issue just polish them with  extra fine sand paper  and  carb clean and blow dry

 

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• This reply was modified 2 years, 2 months ago by crosbyman.

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