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K-Dawg
11-20-2009, 09:07 PM
Will a cracked coil magnet keep a 260 from turning up past 7400 rpm?

http://i46.tinypic.com/30u30av.jpg

The ground strap crossed the magnet where its broke.
http://i50.tinypic.com/svlyps.jpg
Corona Mike
11-20-2009, 10:29 PM
Randy it seems Tom Foley had a problem similar to that. If i'm not mistaken it caused a timing issue and eventualy a rebuild!:eek::eek: Mite want to p.m. him and see what happened in his case. BTW, I have a full set of 260 coils if you need them.
patchesII
11-20-2009, 10:37 PM
da** kdawg. you can bet i'm gonna be pulling covers off of coils tomorrow. my motor is down about 400-500 from where i think it should be. i'm running out of explanations. i've never looked at my coils
Jay Smith
11-21-2009, 09:04 AM
Had a Pro Comp customer one year that was down 800 rpms at top rpm, I did everything I knew to get it back up in the rpm range , to make a long story short I changed to a new set of coils and the RPM came right back up...

Jay
tomoad
11-21-2009, 11:18 AM
whats the parts # for them coils,
wrechin2
11-21-2009, 12:08 PM
I had a 2.4 200 that had 5 crack magnets and replaced all 6 and picked up 400 rpm's. The cracked magnets makes multiple magnetic fields and lowers the output voltage of the coil. JMO.....
Jay Smith
11-21-2009, 12:58 PM
Coil part numbers are 339-832757A4

Jay
gfinch
11-21-2009, 02:27 PM
"The cracked magnets makes multiple magnetic fields and lowers the output voltage of the coil. JMO..... "

Spot On!
David Borg
11-21-2009, 03:57 PM
I had a 2.4 200 that had 5 crack magnets and replaced all 6 and picked up 400 rpm's. The cracked magnets makes multiple magnetic fields and lowers the output voltage of the coil. JMO.....
:iagree::iagree:I would replace them without hesitation
patchesII
11-21-2009, 05:35 PM
i just checked mine. i have 3 coils that are cracked across the coil like randy's second pic. sounds like the consensus is to replace those or will they be ok if you take the loose piece out.
wrechin2
11-21-2009, 06:32 PM
Replace them. The coil is weak if the magnets are cracked......
K-Dawg
11-21-2009, 06:51 PM
Dang. Nothing changed with a change. The coil came off a 1991 200 so, it could be just old. Need to buy all new coils before I decide coils arent the problem.
racer
11-21-2009, 07:14 PM
Check the new ones have recieved many with cracked magnets right out of the box.
sschefer
11-22-2009, 12:16 AM
Check the new ones have recieved many with cracked magnets right out of the box.

Me too. 2 of 6 right from Merc parts online. I think it happens during shipping. They come in a 4 pack and the two that were cracked were not in shrink wrap.

So whats the deal with the blue coils. I hear about them occasionally but not sure what the difference is. The ones I got were the black ones.
Jay Smith
11-22-2009, 08:14 AM
They are very fragile and the way Mercury packages them they are vulnorable to get broken...

Jay