Optimax Spark Plug Gap

[20adamsb]

I have a 2006 Optimax 200 that was repowered with a 2007 250 powerhead. Serial number is 1B424471. What I'm wondering is what to gap the plugs at? I usually take it to mercury mechanic but figured i could do it myself and save a few dollars. The emissions control info on the sticker says NGK IZFR6J gapped to .032" but i see on here its recommended for 2007 and newer optimax to gap them at .042"-.044" Also the serial number sticker for the 200 says max rpms 5750 anyone have any idea what the 2007 250 max rpms are? Thanks

[SilverFox579]

Standard Optimax WOT is 5750rpm, ProXS & XS were higher. I'd follow the plug recommendations in the FAQ.

[EuropeanAM]

.032-.033 for this engine. IZFR5G

[20adamsb]

Alright I just found the serial number off the 250 pro xs that’s where the powerhead came from. It’s a 2007 1B540309. Does that change anything? Just want to be sure. Also an unreleated question but before I get rid of the other engine with the blow head is there anything you would strip to keep for spare parts?

[JOE54]

yep .043-.044

[EuropeanAM]

Flywheel and Alternator are the same... but most everything that bolts to the powerhead on the 200 is different from the 250.

[FeFanatic]

That's what I was wondering. If he put all the 200 components on the 250 will that be an issue with air/fuel ratios? Could this cause his engine to be running lean and not injecting the proper oil amount? It will be interesting to see the amount of performance the 250 powerhead would have.

[20adamsb]

Thanks. Have put at least 300 hours on since the switch without a problem. Boat runs 72mph with ease lol