Motor Issue

fuel supply problem. Pressing the key is equivalent to choking the motor. It sounds like a carbed motor. Pressing the key opens a small solenoid that lets fuel drain from the top carb bowl into the two bottom carbs to provide extra fuel, similar to choking an older motor. If you need to do this to keep it running, you are having trouble getting fuel to the carbs. This could be caused by several things. Check the fuel lines on the left side (looking at the front of the motor) to see if you see any leakage or cracks. Check the line that goes over the top of the motor and the fuel filter. The filter ought to be replaced anyway, you can find them at a dealer, or I use one by Atwood (glass with ceramic element that can be cleaned) which you can find at WalMart. Next stop is the fuel pump, which delivers the fuel to the carbs, using crankcase pressure pulses to provide the energy to pump the fuel. Then check the connector at the powerhead where the fuel line plugs in. Then does the primer bulb pump up normally and get firm? If you pump it up, and let it sit for a few minutes, is it still firm or does it need pumping again? If so, replace it. This wont be an expensive fix, most likely. Even fixing the fuel pump is easy enough if you have any mechanical experience at all, this is similar to the way fuel is pumped on a chainsaw engine. At idle speeds the fuel pump is not that efficient, and if a check valve has gone bad, or there is any sort of restriction between the carbs and tank, it will tend to run lean and die. Without more info, it is hard to diagnose. Could be the carbs need cleaning due to storage/ethanol issues and gunk… however, it is definitely fuel.2008 Pantera Classic2014 Mercury Pro XS 200

Yep, forgot about those. I try to eyeball mine whenever I have the engine hat off. Ive never had any fail, but my dad owned an older merc 850 that developed that problem where the things got brittle. Royal pain in the keister to figure out where they went… Interestingly just helped a family member with an older johnson 88spl (non-oil-injected basement-bargain motor) with this same problem. He had enough trash in the two carbs to choke a small mule. Cleaned it up with new gaskets, needle/seats, etc. Ran for 10 minutes and was back running badly needing the “choke” to run. More trash. Fuel line was too old from tank to motor and was shedding black trash badly. Once we replaced the line from the tank to the powerhead, we were good to go…2008 Pantera Classic2014 Mercury Pro XS 200

Shorten the tuner, reduce the low end torque, pick up on top end rpm since you can get more exhaust out. If you like the sound of a good 2.5, heres how to get it. Pull the powerhead, then the exhaust plate, then the plate with the motor mount. Now pull the exhaust “tube” (the enclosure that takes the exhaust gas down to the lower unit.) Throw it away. Put the motor back together. Take a 3″ hole saw and cut a hole in the center of the midsection on the back. This will vent the exhaust there and not drive it down thru the restrictive entrance to the propshaft bearing carrier and out. It will not be obnoxiously loud. And it will idle like a dream. If you dont like the noise at part throttle, contact land and sea. They have a neat water-activated device that ties into the speedo cable, and covers that rear opening. At about 55mph or so the speedo cable will develop enough pressure to open the valve and push that “plate” that covers the exhaust opening rearward so that you get open exhaust above 55, normal exhaust below 55. I run with the open hole on my XR6. Has a good (not obnoxious at all, but then it is not turning 8500+ like a race motor either) sound, and will gain a little. The 200 tuner is already very short. I think Bobs (florida) makes a flared racing tuner, but it will hurt on the bottom and help on the top. It is not very hard to put on once you are past the motor mounts since you are almost “there”. One caveat. Removing the exhaust liner / sleeve improves the sound, but you will want to change the shift shaft seal every year or two as it will tend to get hot. It wont burn out, but it will get hot, and then brittle, and then start to leak. Its simple enough to replace this since you get at it by removing the lower unit just like when you replace the impeller. Im running a carbed 2.5 (non-stock carbs however, bored out to about the same size as a carbed 200 had) and I love the sound of this motor at speed. It has that “rasp” that the hi-po motors have, without sounding like the big v8 jet boats with the open exhaust headers above water that are _really_ loud. If you have an EFI 175, you might have the ugly _LONG_ exhaust tuner that nearly reaches the lower unit (inside the liner). To tame down the 200 (in 1992 or so) merc restricted the air intake by using small-bore carbs, and then they limited the top end further by using a 2foot+ (at least it seemed that long) exhaust tuner. I replaced that with a 200 tuner which is about 2″ long or so. Lost some low end torque (more in a minute about that) but picked up breathing on the top end. If you want to solve the low end torque, mill the heads. The combustion chambers are quite large. The motors like compression, although they will then need premium gas, not regular. And ramping compression up brings torque right on up with it. Im afraid to guess on a good CC volume for that year, but Im sure you can find advice on the net if you look around. None of this will be any sort of reliability issue, except possibly for the head milling. Bad gas will lead to overheating and burning a piston. Been there. Done that. Got the T-shirt.2008 Pantera Classic2014 Mercury Pro XS 200

How far do you want to go? These engines really have all sorts of room for improvements if you want to play. Though it is extremely time consuming and costly and you will burn your toys up at least once as you learn to tune them usually. Yes remove the exhaust “bucket” and let the tuner breathe. Most of these engines had or have the mid length tuner, which to improve that engine you need to cut the tuner in increments on both sides of the tower. Starting with approximately 1 1/4″ on each side, and increasing that cut by 1/4″ to reach optimum power. Of course you would have to have the carbs tuned in to the spark and burn first. It is a job to do this right, which means pulling the tuner and removing the power head to be making a cut with every run. We prefer to not drill the holes in the midsection and drill relief holes out the bottom of the mid section to relieve that exhaust for hole shot. This will not be as noisy, and still produce on top end. The drilling of the sides on the mid section will only benefit the bottom end split second torque. On a 175 engines you can gain more going to a 200 ECM and removing the 175. This can be done on a 150 engine also. The gain on a 175 is about 1 MPH and maybe more. You can also lean out the engine by increasing the jets in the carbs or throttle bodies, which is another trick to figure out as you have to pull the safety switch and remove each plug while running on the top end as soon as the engine is shut down. Basically cut the switch (kill) and once the boat coasts down pop the plugs and make sure your not leaned out too much by the larger air jets. You can also mill the heads in the .0015 to .0030 range and increase the compression slightly. You can acquire CCd heads from the speed shops already decked and calibrated. Though they are costly. Preferences are the older lost foam heads, and not the multi level flat heads. There is no relative gain in going to a flex flywheel on a bass rig, as the Mercury flywheel is already a light weight piece on these engines. Past this point you get into stuffing the block and changing the reed cage to the larger and less petal reeds with fiber reeds. And yes decked to set them into the intake. Stuffing the block can be done with the older 225 rods and they can be found to interchange with some models. Though they are harder to find by now we are sure. You can stuff the block in other ways to reduce the volume of the crankcase and increase pressure that is the back pressure on the pistons for the return stroke. It will run hard and short though if you stuff the block too much. After this you can enlarge the carb or throttle bodies to larger sections and then your way into trying to figure out what to turn in the air jets and fuel. On the carb and EFI engines it is just how far do you want to go and how long do you want it to run? Since this turned into a gear head thread, now you guys can play any way you need to. And there is way more to it if you prefer. Such as finding an older 1985 2.4 block that resembled the bridgeports and/or the chrome bore models that are clean.

There is only one issue I can think of. Accidents. If you have an accident, you can bet that the motor will be looked at, and when you exceed the CG certification number (which I think is a crock, but thats another subject) your insurance will back away from paying for anything at all. So there is a risk. I cant imagine that boat having problems at 80+ if you are a good driver and use some common sense. My current boat weighs in at around 1400 pounds (just the hull) and it will run 80+ on a warmed-over XR6 all day long using a 28″ prop. A lightweight hull is nice. But horsepower can offset a pudgy hull easily. Ive known river racers that run in every class from 800 pounds to 1400 pounds by adding weight and nothing more. And while they dont accelerate as quickly at 1400 as they do at 800, those things run like a bat out of hades no matter how much weight they have, because they have a _ton_ of horses pushing em. This tweaking and turning is, to me, part of the fun of boating. So long as it is done rationally and safely. There are some people that ought to be limited to 10hp max, of course. 2008 Pantera Classic2014 Mercury Pro XS 200

No on the fuel lines. Stupid question, but where and what are they?…..yea.. I know stupid…..

ethanol in gasoline will cause the inside of older fuel hoses to degrade and come apart. this will plug fuel flow and will cause fuel pump and other engine issues as well. older hoses will have “red” writing where the newer hoses (more resistant to ethanol) will have “blue” writing. there have been plenty of discussions and questions raised on these pages and you would probably do yourself a favor by doing a search. type in fuel hose, fuel lines, or ethanol in the search box.

ok.. I will check the fuel lines. Will a bad battery cause the problems I mentioned? I mean does it take a certain amount of volts to run the fuel pumps and such.. Thanks again. First time my boat ever left me stranded… good thing I have new batteries for the TM.. and was only a mile from launch..