'88 115 power loss

Joined
Sep 1, 2003
Messages
29
Re: '88 115 power loss

One suggestion I saw to check for air is to replace (temporarily as it is not Marine Grade) some hose with clear tubing. This may allow you to see if air is being sucked into any of the fuel lines. I would think the best place would be the 3 lines just before the inlet to the bowl. Maybe even add some extra to form a loop to give you extra time to view the lines. You'd want someone running the boat (of course) for you and you'd probably want to be strapped down. <br />Another person suggested running with the cover off to see if there might be exhaust leak choking the engine.
 

tailgunner

Petty Officer 3rd Class
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Aug 20, 2003
Messages
93
Re: '88 115 power loss

I have to thank everyone here for so much help. I do appreciate it. Unless I find a fix this weekend, I'll be closing this thread.<br /><br />Yeah, I ran it with the cover off everytime. I was able at the dock to put it in gear under load to check things. I'm sure the harbor traffic appreciated this. Not to mention the beginning divers 100 yards to my starboard side.<br /><br />I still think it's fuel delivery. But I am open minded.<br /><br />I'll play with the motor once it's parked on the trailer. I will post any solution.<br /><br />Thanks again.
 

mellowyellow

Vice Admiral
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Jun 8, 2002
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5,327
Re: '88 115 power loss

take advantage of the wealth of knowlege here...<br />do a search on fuel starvation above.<br />good luck,<br />M.Y.
 
Joined
Sep 1, 2003
Messages
29
Re: '88 115 power loss

About your stator test...<br />The manual I just picked up from the library is for years 69-88 but it's a bit different then your readings/test. It says test between the following locations for these ohm readings on a stator:<br />Blue & Red stator leads: 5400-6200 ohms.<br />Blu/Wht & Red/Wht stator leads: 5400-6200 ohms.<br />Red Stator Lead & engine Ground*: 125-175<br />Red/Wht stator Lead & engine Ground*: 125-175<br />*If stator has a black ground wire, be sure ground wire is properly connected to engine.<br /><br />Also to test Trigger - all reading shoud be 1100-1400 between the following:<br />Brown (no yellow sleeve) & White (with Yellow sleeve).<br />White (no yellow sleeve) & Violet (with Yellow sleeve).<br />Violet (no yellow sleeve) & Brown (with Yellow sleeve).<br /><br />Are these different tests than what your manual says?<br /><br />It also says to check the rectifier before changeing the switch box to be certain is working correct and doesn't toast the new switch box. But that might be for some other style in-line 6 - this manual is somewhat confusing in that it puts stuff in several places and this statement was in a section for "wiring & connection test (models prior to 76)" -- so it might not apply.
 

tailgunner

Petty Officer 3rd Class
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Aug 20, 2003
Messages
93
Re: '88 115 power loss

I pulled the stator test instructions from several different sources online, including MarineDoctor. The Clymer manual absolutely stinks.<br /><br />We are all convinced that it's carbs at this point. I'm pulling the boat this afternoon and then the carbs. They'll be rebuilt by a local Merc mechanic. Then we'll see.<br /><br />I put a clear "gunk" filter in place of the stock plastic one this morning. Amazing to see all those tiny specs but really helps to see fuel delivery.<br /><br />I did notice today the the primer bulbs (I tried 2 different ones) would get rock hard. When this happened I could pump nothing through them.
 
Joined
Sep 1, 2003
Messages
29
Re: '88 115 power loss

Could you help me out with On-line sources you found for info on testing Stator, Packs, Rectifier etc. as I'll be doing these tests as soon as I find some spare time. <br />Thanks
 

tailgunner

Petty Officer 3rd Class
Joined
Aug 20, 2003
Messages
93
Re: '88 115 power loss

FMR,<br />Check your email.<br /><br />The boat is on its way to mechanic this morning. Begged a favor and they will diagnose it for me.<br /><br />$90/hr is the going rate for mechanics down here!
 

Gary Stern

Recruit
Joined
Sep 9, 2003
Messages
1
Re: '88 115 power loss

We have a similar problem ('86 V6 150hp Merc). Tested with an aux tank and hose and this fixed it. Looks like clog in the tank. Evidence was collapsing bulb after pumping during poor running performance (pumping bulb helped engine run, but looks like a restriction somewhere upstream exists that was preventing the bulb from fully filling after this pumping). Thanks for all your write-ups! -G (p.s.-we replaced the stator before this test...)
 
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Sep 1, 2003
Messages
29
Re: '88 115 power loss

So Tailgunner, what happened? What did it turn out to be?<br />I hope your out there catching some fish!
 

tailgunner

Petty Officer 3rd Class
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Aug 20, 2003
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Re: '88 115 power loss

Boat is on trailer. I'm still waiting on the paperwork from seller to register the **** trailer so I can take the boat to a mechanic. Current plate expired in 2001. Not a problem around town but the mechanic is about 25 miles away.<br /><br />I'm ready to call it a season. The big fish are in but will not be around for more than 2 weeks. Yesterday 3 friends caught a total of 8 stripers. All weighed in at more than 40lbs each.<br /><br />I'm depressed but not giving up yet.
 
Joined
Sep 1, 2003
Messages
29
Re: '88 115 power loss

Looks like I need Packs - Know anyone that has a working set and can ship them to me quickly before my kids grow up and don't want to go with Mom & Dad - even to have fun water skiing? <br /><br />Swaping wires from trigger at the pack shows that plug 1 (that worked before) will fire when any trigger wire is connected to it - so trigger works. I checked the stator resistance and it seems good. I checked the rectifier and it doesn't seem bad - somewhere I read said if it's bad it could blow the packs.
 

ossola

Cadet
Joined
Sep 10, 2003
Messages
8
Re: '88 115 power loss

Tailgunner, before you call it a season, pull the number two carb (my guess but check them all) and inspect the float. I'm willing to bet it has a small hole or crack in it that is allowing fuel to enter. Had same symptoms as you and found a bad float. I say the number two carb because you are OK during idle. Its worth a shot...<br /><br />Let us know how it goes.
 

tailgunner

Petty Officer 3rd Class
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Aug 20, 2003
Messages
93
Re: '88 115 power loss

Andy O,<br />I pulled all 3 a week or so ago. I inspected the floats pretty closely on all and saw nothing.<br /><br />2 things I found while on trailer. Lower unit gear oil and had not been changed in many years. Very nasty looking, green and tan. This tells me water had gotten in there. The other was the ground wire to the choke was loose causing intermittent problems.
 
Joined
Sep 1, 2003
Messages
29
Re: '88 115 power loss

New NOT GOOD Info on my motor. I checked voltage from stator while still connected to original packs. Using a Fluke with Min/Max Record capability I checked from ground to red (red/wht on pack 2) when good they are 120 VAC peak (they should be 180?) then the Blue (Blu/Wht) are 30 peak (should be 20) - when I move some of the stator wires that go to the packs things change - I get an ever increasing jump on the peak voltage in about 40 volt incriments. Haven't disconnected anything yet. Looks like possible broken wires or shorts due to bad insulation in the bundle between packs and ignition coils. I'll have to check further - ran out of time / light tonight.
 
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