Are sierra coils Junk or What ????????

[Bodine]

I have a 87 Johnson V6 with 4 bad coils that won't jump the 7/16 sparktest and 2 coils that will . So I went the cheapo route and got me 4 Sierra replacement coils and installed them accordingly and tried the spark test on the new coils . Started and 7/16 .... nothin .... Went to quarter ...nothing .... 3/16 ..... still nuthin ..... 1/8..... they finally sparked ..... needless to say they are no better than my old coils that I am replacing . I moved the 2 good coils all around to diffrent cylinders and they passed the test on every cylinder ... That makes the new coils not up to par .... Anybody run into this ? All four of the new sierra coils will not jump anything higher than a 1/8 gap .... Tested over and over to be sure and I would of thought the sierra stuff would work fine .... Suggestions ??? Thanks in advance

[rgsauger]

I think i gapped my ngk's at either .035 or .040" for my merc 200. Not sure if they would jump the gaps you are trying or not.

[outasite]

Are you moving the wire with the coil?Could be some wires with high resistance.

[Bodine]

Are you moving the wire with the coil?Could be some wires with high resistance.

The wires are brand new mallorys , but I did try all the wires to eliminate that problem . I have good 7/16 jumping spark on all cylinders with the two good coils that I have (oem omc coils) , but the 4 sierra coils will only jump a 1/8 " gap . It pretty much tells me that my primary ignition system , ( stator , timer base , power pak ) is working up to snuff . How important is the 7/16 gap test anyway ????? I am chasing a misfire at idle in gear that pretty much disappears when I throttle up and cruise , runs fine then . I have rebuilt and inspected the carbs , regasketed everything on the intake , inspected the reeds , compression test ... everything is good . One thing I noticed is when I bought these coils from Marine engine .com , they showed a pic of the coil that says "Made in Germany " but the coils I got say Made in China .... I contacted MarineEngine .com and they say that all there coils are oem quality and shouldn't be the problem ... Yeh Sure ....

[Ted Stryker]

Sierra coils that Ive used were junk... Junk parts or the insulting prices for quality replacement parts is 80% reason why Ive all but stopped tinkering with this stuff..

[frederick55]

The ones made in Germany should probably be Bosch. Used Bosch on my looper and they are great. Come to think of it, I got them from outboardparts.com. These guys pulled a switch on you, but in their defense, the parts are shipped from another warehouse. No way that Chinese stuff is as good as Bosch. You should have 7/16" spark jump, so it's no wonder it won't idle. You might check for clean ground connections on the weak coils.

[Bodine]

Thanks for the info ^^^^ .... I agree .... Marineengine.com has pawned me off to Sierra to warranty even though they sent me the chinese coils to begin with ....Never buying Shyte from them again ....Thanks for all your help everybody ...

[CharlieB53]

Return the Chinese coils as defective new parts.

Insist on either American made or Bosch coils and tell them you will test them same as you have these.

The 7/16 arc test is critical as under peak load running the amount of air stuffed into the plug gap under compression roughly equates to a 7/16 gap in free air. Failure to arc that gap in free air almost guarantees a failure to arc at WOT.

[stoker2001]

my experience is with a merc 2.5 Drag and i tested the Mallory coils which are made in Germany by another company (name slips me).these are half the cost of mercs these days and they look way better quality then Mercs crude finish.They did have different ohm readings,but performed flawless to 10K RPMs