87 xr2 150 spark plug question

[mercxr2150]

Hello I removed the oil injection on this motor and I am having problems with no wake zone idling and get to the boat lane and it takes a while to burn the fouling off. I had posted on here earlier this year and someone told me I could go from the NGK BU8H to BR9HS-10 and it would help with this. I asked a guy at the local merc shop for those plugs and he said it would burn a hole in the pistons. But of course he still sold them to me. Just wondering if this is true or not. Any info would be much appreciated.

 

[Dukedog]

BU8H is all ya need. Buy it at tha car parts store. Tha other one ya mentioned is more for lots newer EFI and/or 'lectronic controlled motors, and hot rods. And no they won't "burn" a hole in it..........Pre-mix won't have anything ta do with any type of what most call a "foulin' problem"............Thats usually a minor tune-up and/or minor fuel delivery problem.

 

[Chris1956]

You are pre-mixing the fuel at 50::1 right? As Duke says, normally the fuel mix won't foul the plugs unless it is 16::1 or lower. Stick with the BU8H plugs. Suspect the fuel pump leaking fuel into the crankcase, if the fouling persists.

 

[mercxr2150]

Thanks for the responses. Yes I am running 50:1. I mean I'm not having problems with it just after 5 minutes of idling when you get in to it a little bit it takes 20 to 30 seconds for it to come alive and the boat will instantly come out of the water. If you pin it to wot its 10 to 15 seconds. Thank for the advice guys I'm going to play with it this weekend it's in the water till Monday.

 

[Chris1956]

Sounds like a bad fuel pump diaghram, allowing some fuel to get into the crankcase when idling. When you increase throttle, the extra fuel is burned or exhausted.