Just a question for Don. Since we know the gas was bad, could it have fouled some of the injectors? Or could it be something as simple as fuel flow restriction caused by the bad gas?
Just a question for Don. Since we know the gas was bad, could it have fouled some of the injectors? Or could it be something as simple as fuel flow restriction caused by the bad gas?
1998 Starcraft Superfisherman 170SC, 99 Force 90hp
I would be surprised if was the injectors- much more likely that a restricted/contaminated filter is at play. That being said- restricted/dirty injectors ARE a possibility, given the low hours on the engine (and the bad-fuel scenario).Originally Posted by blackxpress
Be sure to report back on their findings- sounds like they're planning to check the BASICS first (an excellent approach).
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
I apologize for never getting back about this problem, which still exists, but we may be headed in the right direction. I have been out of pocket for a while, but that's another story. Anyways, the motor was still only getting 5200 rpms, and top end was bumping 50 mph. Took it to BPS in Shreveport, had the fuel drained, and computer hooked up. The mechanic working on it actually seemed like he wanted to get it right this time. He ran the motor on the computer and did all sorts of computerized tests and everything checked out good. He showed me the numbers on the computer, which the last person would not do, and the highest rpms it has ever been is 5820. He then checked the trim percent and thought is was low, so he changed some numbers in the computer. I believe he raised the percent for the trim up 5 percent to maybe 30. On the way home, I put 5 gallons of fresh gas in and ran it for a few minutes. I was able to bump 5400 rpms and hit almost 53 mph. Still not getting good bow lift, but its better and the spray is farther towards the back of the boat now. Can anyone tell me the correct percent of trim the computer should be set at, and how would it have changed? The motor serial number is: 1B992937, and has 55 hrs on the motor. Thanks in advance.
Try a different prop
Normally set at 20 degrees trim angle.
The most common cause of changes in this area would be a worn or malfunctioning trim sender.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Thank you for the replies. I took it out fishing on Sunday, and the rpms are back down to 5200 and speed is back at 50 mph. I called Mercury and they said they could only speak about the issue with the mechanic. Still waiting to hear back from the mechanic about this. Getting pretty frustrated.
What is your Zip Code?
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
My zip is 71009. Blanchard, Louisiana
Not sure what dealer you're at, but some of the higher-rated ones include:
-Tracker Marine (BPS) in Bossier City
-Town & Country Marine in Longview, TX
-Tracker Marine (BPS) in Longview, TX
-Nichols Marine in Longview, TX
You can also view others by checking: Mercury Marine Dealer Locator
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
I have been dealing with Tracker Marine at the BPS in Bossier since that's where I bought the boat new. I went there yesterday and talked to the service manager, and he didn't seem interested at all. I politely told him I was bringing the boat back to him when the water levels go down a bit so they car run it on the river with the computer hooked up, and didn't want it back until it is 100% fixed.
When ALL potential external causes have been ruled out... let's consider an INTERNAL cause (such as a rotated cylinder sleeve). In most cases the engine will run fine... but be down on power.
Also in many cases, if a cylinder misfire test is done (with the Computer Diagnostic System) at WOT, while on the water... most cylinders will average a 400 RPM drop.
One with a rotated sleeve will usually have a RPM drop that is less than the others...
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Thanks for your insight. I really hope its not a rotated sleeve and is something very simple.
Just curious what the final outcome was with your motor? Mine has the same problems and symptoms your describing.
Mine is in the shop now for the same reason only turning 5900 RPMS should be 6250-6290......the wait begins!
Check your plug for your trim pump. Mine was doing the same thing and the plug wasn't tight plugged it back up and everything seems fine now.
Please open a separate thread for your separate engine- there may be a very good reason or reasons for this (quite simple).
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Just wanted to give an update. Sorry for it being late, just have been busy and not around much. Havent been on the water since last July. Took it out Saturday and the problem is worse. Couldn't get above 4900 rpms and 43 mph. Bow rides very low, but had a good rooster tail. I added fresh gas before the trip. Waiting on mechanic to call me and tell me when to bring it in. Hes saying it sounds like a fuel problem or something about a lower unit tightening up? Hopefully this gets right. If not, I'm about ready to get rid of this boat and motor.
Probably is fuel system related... sitting for 6-7 months probably hasn't helped.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
And its probably not covered under warranty. At this time, I just want it fixed. Don't really care what it is, having/driving a boat that doesn't perform like it should sucks.Probably is fuel system related... sitting for 6-7 months probably hasn't helped.
Dropped it off at the mechanic at lunch. Checked the prop and it had a lot of play(wobble). He took it off and the prop hub was cracked. He says it looks like a manufacturer defect. Put a new on and its good to go. Hes gonna drive it while the computer is hooked up and get back to me.
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