NorthwestBasser Posted June 5, 2017 Posted June 5, 2017 I have a 1988 skeeter sf175 with a 115hp mercury "tower of power". I'm having a weird problem and not sure if it's a throttle linkage issue or a motor issue. Some times when I go to take off I can't get the boat up on plane, but when I stop, put it in reverse and rev it way up I can then shift back into forward slam the throttle and get a decent holeshot... anyone have an idea what may be going on here? In addition, when running at 3/4 to WOT if I back off the throttled say half or 1/4 speed then want to go back to full speed my motor stays at the half or quarter power unless I back off into neutral first at which point I can then get back to full throttle. Very confused... Quote
NorthwestBasser Posted June 6, 2017 Author Posted June 6, 2017 Guess I did the impossible and stumped the vast wealth of knowledge that is BassResource! Quote
BobP Posted June 6, 2017 Posted June 6, 2017 Sounds like a throttle linkage or fuel delivery problem. Some problems are just better diagnosed and corrected by a qualified marine mech. 1 Quote
Super User A-Jay Posted June 6, 2017 Super User Posted June 6, 2017 "Slam the throttle and get a decent holeshot" ~ Perhaps take your rig to an authorized Mercury Dealer & have it serviced by humans who actually know what they are doing. Or - you could just keep slamming. A-Jay 5 Quote
NorthwestBasser Posted June 6, 2017 Author Posted June 6, 2017 I plan on taking it in to a mechanic, just trying to see if anyone had some similar experience and could shed some light on what i may be dealing with. And no, I'm not continuing to "slam" the throttle. I suppose that was a poor choice of verbage on my part... Quote
Super User A-Jay Posted June 6, 2017 Super User Posted June 6, 2017 33 minutes ago, NorthwestBasser said: I plan on taking it in to a mechanic, just trying to see if anyone had some similar experience and could shed some light on what i may be dealing with. And no, I'm not continuing to "slam" the throttle. I suppose that was a poor choice of verbage on my part... Yea ~ You know what it's like . . . . . Kind of tricky diagnosing & or trouble shooting long distance. Be curious to hear what's broke though. A-Jay 1 Quote
Super User fishnkamp Posted June 6, 2017 Super User Posted June 6, 2017 If I were to guess, I would bet on a problem with the wire inside the throttle cable and or the sheath that surrounds it. I have seen similar issues before. The other issue could be an issue with the internals of your fuel line degrading. The fuel line issue is a highly documented one. Lastly you may have a prop with a hub going bad. IF you are up on plane and going fine, then drop the throttle back, does the engine rev up but not jump on plane or is the engine just sorta dead? Quote
NorthwestBasser Posted June 6, 2017 Author Posted June 6, 2017 6 minutes ago, fishnkamp said: If I were to guess, I would bet on a problem with the wire inside the throttle cable and or the sheath that surrounds it. I have seen similar issues before. The other issue could be an issue with the internals of your fuel line degrading. The fuel line issue is a highly documented one. Lastly you may have a prop with a hub going bad. IF you are up on plane and going fine, then drop the throttle back, does the engine rev up but not jump on plane or is the engine just sorta dead? I'd say more on the sorta dead side, it's still running smooth, I just can't bring it back up to higher rpm's without bringing it fully back into neutral, then throttling up again. I've considered the throttle cable/sheath and haven't discounted that yet, also thought about the prop being spun as the prop on here is very beat up (just bought the boat) and plan on a new prop in the next week or so. Fuel lines are less than a year old and look in new condition still, at least from the outside. @fishnkamp thanks for the reply, the issues you listed are ones I was hoping to hear feedback on. They seem like less expensive repairs than motor work. But I'll get it into the shop this week and see what they say. Plus a full tune up. Quote
Super User fishnkamp Posted June 6, 2017 Super User Posted June 6, 2017 Okay if the engine had revved up, but you did not accelerate the boat, then I would have been suspect of the prop. A mushy feeling engine response says several things to me. Either your cables are bad and stretching, thus not pulling the engine throttle to full throttle or you may have a clog in the fuel system. Since you did say the fuel lines have been replaced. I would try a few things. Have someone sit in the boat and watch as they put the throttle lever to full throttle ( engine not running) Visually verify the throttle linkage on the engine is reaching the stop. Next I would put the boat in the water with the engine being fed by an external fuel tank, like a 3 to 6 gallon tank. I would have new fuel mixed with the proper oil and I would add a can of SeaFoam to it. If the engine runs better after the smog clears then it may have been a clogged carburetor issue. There is one other thing to consider. I owned two of those engines and I loved them. However, they run several coil packs and when one goes then you loose a cylinder or two. You could be having one of those going bad. The pros can test them. If that turns out to be the issue then I suggest that if one is bad replace them all. If you do not they will haunt you over and over again. 1 Quote
NorthwestBasser Posted June 6, 2017 Author Posted June 6, 2017 @fishnkamp I've heard differing views in the Seafoam... one side says it's great stuff, the other says never use it as it could eat up head gaskets in older motors, you know of any truth to that? Quote
Super User Way2slow Posted June 6, 2017 Super User Posted June 6, 2017 One would have to assume you have pulled the cover and verified the linkage is fully advancing and the you have looked in the throat of the carbs to verify they are fully opening. Also the timing is fully advancing and not stopping half way. Anything beyond the obvious mechanical problem is going to require some hands on trouble shooting by a very knowledgeable person, there are a list of potential problems. If this was not one of the first things you did, I would recommend you take it to a mechanic due to a total lack of motor knowledge. 2 Quote
NorthwestBasser Posted June 6, 2017 Author Posted June 6, 2017 2 hours ago, Way2slow said: One would have to assume you have pulled the cover and verified the linkage is fully advancing and the you have looked in the throat of the carbs to verify they are fully opening. Also the timing is fully advancing and not stopping half way. Anything beyond the obvious mechanical problem is going to require some hands on trouble shooting by a very knowledgeable person, there are a list of potential problems. If this was not one of the first things you did, I would recommend you take it to a mechanic due to a total lack of motor knowledge. So helpful, thanks for your input... Quote
Super User fishnkamp Posted June 7, 2017 Super User Posted June 7, 2017 My friend was a regional rep for Kawasaki motorcycles and they used it all the time. I have other boating friend that have used it for decades without trouble. I am not sure I have ever heard any mechanic say a bad word. I am an engine builder by trade and have used it for at least 10 years myself. I am sure it can be misused, just the same as anything else. If you are using it while running the engine at a fast idle the engine should be fine. 1 Quote
blackmax135 Posted June 20, 2017 Posted June 20, 2017 On 6/4/2017 at 8:45 PM, NorthwestBasser said: I have a 1988 skeeter sf175 with a 115hp mercury "tower of power". I'm having a weird problem and not sure if it's a throttle linkage issue or a motor issue. Some times when I go to take off I can't get the boat up on plane, but when I stop, put it in reverse and rev it way up I can then shift back into forward slam the throttle and get a decent holeshot... anyone have an idea what may be going on here? In addition, when running at 3/4 to WOT if I back off the throttled say half or 1/4 speed then want to go back to full speed my motor stays at the half or quarter power unless I back off into neutral first at which point I can then get back to full throttle. Very confused... Have you checked to see how the boat is peeing? Quote
NorthwestBasser Posted June 20, 2017 Author Posted June 20, 2017 @blackmax135 ya, new impeller good water pressure. Ended up being a stuck accelerator pump. Also was over propped, dropped down to a 17p. Other than that I'm just a little underpowered. By myself or with my girlfriend it pops right up on plane now. Me and my 245lb brother in law she has to work a little harder to get up there, lol Quote
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