Hello, this pertains to my 1997 Tracker (Mercury) 40hp 2-stroke (4 cylinder) on my Tracker Pro Team 17, which is, obviously, 17 ft long. What should the compression be? I am reading 85-90 lbs on all 4 cylinders. Seems low but I don't know much. I borrowed a friend's compression tester, which is a Harbor Freight tester. Not sure how reliable this is but all cylinders read about the same.
I checked this because it was suggested after I had a lot of trouble starting. I suspected foul gas. I have owned it a few years and have only used e-free gas but it has sat up for multi-month stretches here and there, so, fuel could be an issue. I can only crank it after I advance the throttle in neutral. I finally figured that out, lol. I also have to choke it each time it wants to die. Once I luck up and get it going to where it isn't going to die, it moves along nicely and then after it's warm, I gas it and it runs flawlessly at top speed of 30mph.
I bought this used from an older gent and it's in great shape cosmetically but according to his son, he let it sit unused for very long periods of time and he told me they changed the water pump and all the fuel lines and tuned the carburetor, might have done more to carb than just tune it, I don't recall... all of that to get it ready to sell. But I see indications they got into the motor cuz I see that red seal/gasket stuff and that does not look like factory work to me but again, I don't know for sure. Point being, they might've done more internal to the motor than what he told me.
I just put new plugs in it. Not a big change. I also de-carbed it, ran Sea Foam through according to a video I saw, lol. All of this, not a big change but it has def gotten a little better. I also advanced the idle but now the screw it maxed out. It's fishable but I need to get this motor purring even if I have to take it to a mechanic.
What does 85-90 reading on compression indicate if anything and is it bad?
I checked this because it was suggested after I had a lot of trouble starting. I suspected foul gas. I have owned it a few years and have only used e-free gas but it has sat up for multi-month stretches here and there, so, fuel could be an issue. I can only crank it after I advance the throttle in neutral. I finally figured that out, lol. I also have to choke it each time it wants to die. Once I luck up and get it going to where it isn't going to die, it moves along nicely and then after it's warm, I gas it and it runs flawlessly at top speed of 30mph.
I bought this used from an older gent and it's in great shape cosmetically but according to his son, he let it sit unused for very long periods of time and he told me they changed the water pump and all the fuel lines and tuned the carburetor, might have done more to carb than just tune it, I don't recall... all of that to get it ready to sell. But I see indications they got into the motor cuz I see that red seal/gasket stuff and that does not look like factory work to me but again, I don't know for sure. Point being, they might've done more internal to the motor than what he told me.
I just put new plugs in it. Not a big change. I also de-carbed it, ran Sea Foam through according to a video I saw, lol. All of this, not a big change but it has def gotten a little better. I also advanced the idle but now the screw it maxed out. It's fishable but I need to get this motor purring even if I have to take it to a mechanic.
What does 85-90 reading on compression indicate if anything and is it bad?
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