Plug gap

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Mark B
Posts: 25
Joined: Sun May 19, 2019 1:36 pm
Location: London

Plug gap

Post by Mark B » Sun Jun 09, 2019 10:30 pm

I am pretty sure the plug gap for my Silver Century 90 is 25 thou..I can’t find my Worksop manual and I can’t find it on the SOS site??? It must be me, I have been surcharging for the last hour!!!

Help!

Mark

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Charles uk
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Location: Maidenhead Berks UK

Re: Plug gap

Post by Charles uk » Mon Jun 10, 2019 12:33 am

It's dependent on which type of ignition you have fitted to your model 90, black or white CDI.

A picture of the flywheel rim will tell us.
Make it idiot proof and someone will make a better idiot.

Mark B
Posts: 25
Joined: Sun May 19, 2019 1:36 pm
Location: London

Re: Plug gap

Post by Mark B » Mon Jun 10, 2019 7:39 am

This is all I have today...

Thank you.

Mark
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Charles uk
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Re: Plug gap

Post by Charles uk » Mon Jun 10, 2019 8:21 am

Well the White CDI is 35 thou & the Black 25.

I run both at 25 thou & haven't had a problem yet.
Make it idiot proof and someone will make a better idiot.

Mark B
Posts: 25
Joined: Sun May 19, 2019 1:36 pm
Location: London

Re: Plug gap

Post by Mark B » Mon Jun 10, 2019 9:47 am

Thanks for that....
I did just put a post up, but it didn’t down load...
I found my hand book and on page 18 it said 35 t.
I get the gaps mixed up with my chainsaws... must be my age!
Thanks again mate that’s great.

Mark

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Charles uk
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Re: Plug gap

Post by Charles uk » Mon Jun 10, 2019 9:57 am

Yours is a factory rebuild & that doesn't tell us which ignition they fitted.

Remove flywheel cover & inspect flywheel rim,

no groove white CDI

groove black CDI

Run at 25 thou until your sure, as the black CDI struggles at 35 thou, & replacements are expensive!
Make it idiot proof and someone will make a better idiot.

Mark B
Posts: 25
Joined: Sun May 19, 2019 1:36 pm
Location: London

Re: Plug gap

Post by Mark B » Mon Jun 10, 2019 10:21 am

That’s interesting... tell me more.. factory rebuild???
I got the Engine with my boat around 18 years ago..
Got from my mate... an old boy had it before him and looked after the engine...
Be interested to know.

Thank you

Mark

Mark B
Posts: 25
Joined: Sun May 19, 2019 1:36 pm
Location: London

Re: Plug gap

Post by Mark B » Mon Jun 10, 2019 10:24 am

Ps... is it straight forward job removing the fly wheel cover?

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Charles uk
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Location: Maidenhead Berks UK

Re: Plug gap

Post by Charles uk » Mon Jun 10, 2019 1:25 pm

Sorry getting you mixed up with another Seagull can't say anything about yours, as we don't have the engine number.
Make it idiot proof and someone will make a better idiot.

Mark B
Posts: 25
Joined: Sun May 19, 2019 1:36 pm
Location: London

Re: Plug gap

Post by Mark B » Mon Jun 10, 2019 2:06 pm

Sorry, yes, EFNR16JJ9

Mark

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Charles uk
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Joined: Wed Feb 27, 2008 4:38 pm
Location: Maidenhead Berks UK

Re: Plug gap

Post by Charles uk » Mon Jun 10, 2019 6:33 pm

Undo the 1/4" BSF bolts below the baseplate, these should release the flywheel cover & with luck you should be able to lift it enough to see the bottom 1/2" of the flywheel rim & be able to see a shallow groove 3/8" above the bottom of the flywheel base, if the groove is present you've got a Mk 4 Wypac CDI 25 thou plug gap.
Make it idiot proof and someone will make a better idiot.

Mark B
Posts: 25
Joined: Sun May 19, 2019 1:36 pm
Location: London

Re: Plug gap

Post by Mark B » Mon Jun 10, 2019 6:41 pm

I think you have me mixed up with the factory rebuild Seagull.
You asked me for the engine number.,
It’s ok mate, you must be spinning those old plates!

Mark.

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