Mercury 150 xr2 bored .040

[llyons]

Recently lost 2 cylinders to pre ignition damage. Shop says they can take it to .040 with rebuild.

Is this a reasonable solution? Shop says the cylinder sleeves are thicker on the 2.0 motors and .040 is no problem. Are there any issues i should be concerned with?

 

[Dukedog]

who makes pistons .040 for it? jus never heard of 'em? ya probably wanna go up in main jet size (depends on how much over size bore ya go) for anything bigger than .015...... will need ta watch piston tops and plugs ta get jetting right.......

 

[llyons]

who makes pistons .040 for it? jus never heard of 'em? ya probably wanna go up in main jet size (depends on how much over size bore ya go) for anything bigger than .015...... will need ta watch piston tops and plugs ta get jetting right.......

The guys at shop suggested it and they are considered reputable. Here is an example rebuild kit at .040

WSM Mercury 150 HP XR2 2.0L 6 Cyl. Rebuild Kit '86-'88 .040 SIZE - 100-50-24 | eBay

Power Head Rebuild Kit- Use with bottom guided rods #636. 6 Cyl 3.125 Bore 2L XR2 150. Kit includes everything you need to re-build your outboard engine.040 SIZE ONLY 3.165".

www.ebay.com

I just wasnt sure if anyone has done this and did it work out?

 

[Dukedog]

that would probably work with tha 2.0 motor.. i've run up ta .030 without any problems.. WSM is pretty reputable....

 

[Faztbullet]

Need to find the problem that caused the damage or it will happen again Which cylinders was damaged?

 

[llyons]

Need to find the problem that caused the damage or it will happen again Which cylinders was damaged?

Hi Faztbullet,

We lost 3 and 4 as discussed in this recent thread. https://forums.iboats.com/threads/m...ng-to-get-on-plane.770571/page-3#post-5902622

Shop think’s pre ignition issues and therefore they suspect the trigger and power packs?

Im curious if people have any experience with the .040 over scenario? Seems like wiseco wsm all make kits for .040?

Does anybody have experience on this?

 

[Dukedog]

JMO... anytime ya go .030 or more ya need a very good mech or you need ta be able to read piston top and/or spark plugs.. there is a reason merc doesn't offer anything over .030 pistons (2.0 motors only), everything else steel is .015..... like said, JMO.

 

[Faztbullet]

Just go up 2 sizes on mains and down one on idle. Surface heads just enough to make flat or use newer "top hat" heads.

 

[llyons]

Just go up 2 sizes on mains and down one on idle. Surface heads just enough to make flat or use newer "top hat" heads.

Thanks for the info. Mechanic is well respected and works racing boats frequently. Keep my fingers crossed. This motor is giving all she has.