what should the compression be on a 1989 XR4 150 HP Mercury
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what should the compression be on a 1989 XR4 150 HP Mercury
My dad has an 89 xr4 and it runs 118-121,if you have a drop of 5lb or more you want to pull the head and check the cylender.as long as they are all evenly close they can be less than that i have seen some with 105-107.if you suspect cylender problems do a leakdown test it will tell you more abot ring and cylender condition.
Thanks fir the info, I am getting 121-125
That looks pretty good,do you suspect some sort of problem or just wondering?
Last time out it wouldn't jump up on plane like normally, must be the gas which I had just topped off