URGENT - Spark plug help

[tomandjen43150]

So I can not find any thing on my outboard that tells me what size other than the cover. Title says 125, that is what it is suppose to have, cover says 120. I need to change the plugs. I pulled out a 587(L6VC), 125 calls for 824(UL18V). 120 calls for 898(QL76V). What the hell do i do?

 

[huskerdaninva]

Re: URGENT - Spark plug help

Check out the engine data plate. Should be towards the front lip of the motor housing. The model number should tell you what you need. The first two digits should reflect the HP rating. Then you can do a little research on the web and determine what plugs you need. Hope this makes sense.

 

[tomandjen43150]

Re: URGENT - Spark plug help

Only numer I can find is on the powerhead #P742622 ? Not sure what that is. There has got to be a way to figure this out

 

[foodfisher]

Re: URGENT - Spark plug help

On the cowling base, under the carbs, where the throttle and shifter cables enter should be a tag with id info on it. If not, a pic would be a great help.

 

[pnwboat]

Re: URGENT - Spark plug help

Depends on what type of ignition system you have. If you have the early type Prestolite ignition system that uses 2 of the blue or black CD modules to drive 4 coils, then you use the Champion UL18V's. If you have the later Mercury Thunderbolt type ignition system that uses a single "switch box" to drive all 4 coils, use the QL76V's.

 

[tomandjen43150]

Re: URGENT - Spark plug help

It is a prestolite and I used the UL18V. I do not have any tag that tells me what engine I have. If I go by the wiring chart in the clymers I have a 120.
I beleive the Powerhead may have been replaced. The boat is suppose to
have a 125.