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1990 Baja 250
just curious what spark plugs i should be running in stock 502 jasper motor in my Baja? right now i have NGK R (BR6FS) plugs. Had dads friend who is mechanically inclined that he doesn't think they are right, it thinks i should be running NGKUR4? any input on what i should be using?
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What is a jasper motor? First time i hear that
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Originally Posted by jeff32
(Post 4934751)
What is a jasper motor? First time i hear that
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Originally Posted by Leick238
(Post 4934753)
jasper motor is just remanufactured 502. Think their built more durable
The BR6FS are the correct spark plugs for a Merc 502. I assume your Dad's "mechanically inclined" friend doesn't work on marine engines. UR4 plugs are too hot and could cause detonation. You could run a UR6 which is the same heat range as the BR6FS with a projected tip |
Originally Posted by Griff
(Post 4934760)
Definitely not more durable than OEM Merc. Jasper are ok, but their marine engines have a much higher failure rate than Merc.
The BR6FS are the correct spark plugs for a Merc 502. I assume your Dad's "mechanically inclined" friend doesn't work on marine engines. UR4 plugs are too hot and could cause detonation. You could run a UR6 which is the same heat range as the BR6FS with a projected tip |
Originally Posted by Griff
(Post 4934760)
Definitely not more durable than OEM Merc. Jasper are ok, but their marine engines have a much higher failure rate than Merc.
The BR6FS are the correct spark plugs for a Merc 502. I assume your Dad's "mechanically inclined" friend doesn't work on marine engines. UR4 plugs are too hot and could cause detonation. You could run a UR6 which is the same heat range as the BR6FS with a projected tip Any specific known reasons for the higher failure rate? I've always heard good things about Jasper engines, so I figure it's a marine thing. Bearing clearances? Valvetrain? Curious. Thanks. Brad. |
Originally Posted by Brad Christy
(Post 4934770)
Griff,
Any specific known reasons for the higher failure rate? I've always heard good things about Jasper engines, so I figure it's a marine thing. Bearing clearances? Valvetrain? Curious. Thanks. Brad. |
BR6FS Cross’s to delco mr43t which is correct plug for merc 502/rectvport cast iton head motors. Gap to .035”.
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i run NGK ur5 they work awesome
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Originally Posted by boostbros
(Post 4934782)
i run NGK ur5 they work awesome
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