|
|
Posts: 795
Location: Delavan, WI | On a recent fishing trip my motor started acting kinda funny- at least it didnt do it until the last day- it starts and runs good at idle- no missing or sputtering, but will not go over 2000 RPM in gear- it will rev up higher if you do it neutral, but under a load it just completely lacks power almost seems as its not getting enough fuel- I am going to try a fuel filter 1st- hopefully that takes care of the problem- I think it may also have a fuel pump since its an EFI motor- however I am unsure of its location, since I am an auto mechanic by trade Im pretty sure I can handle the repar- just don't know how to go about diagnosing it-- has any one ran into the same problem??? |
|
| |
|
Posts: 295
Location: Southern Ontario, Detroit River and Lake StClair | Most of the larger Mercs that I've delt with had an "auto shutdown" to speak off that wold limit your RPM's to 2000 if there was some kind of problem like a water pump failure or an oil injection pump failure. the last one was a 200 EFI. It did pretty much what you said except it would run for a bit first then just die out when on plane and then wouldn't go over 2000 RPM. It turned out to be a bad impeller in the water pump. It was spitting water from tell tale but not putting out enough pressure when on plane to keep things going.
Good Fishin'
Tim
|
|
| |
|
Posts: 795
Location: Delavan, WI | Hey Thanks for the reply Tim, but wouldn't the alarm under the dash go off if the impeller was bad due to overheating ? |
|
| |
|
Posts: 295
Location: Southern Ontario, Detroit River and Lake StClair | It wasn't over heating. The pump just wasn't putting out proper pressures and it shut the motor down before it did over heat. The motor had Smartcraft gauges. Just something to think about.
Tim
|
|
| |
|
Posts: 795
Location: Delavan, WI | Well I changed the fuel filter and it seemed to help a little bit- it still doesnt have full power, but it went above 2000 RPM- I also did a compression check on each cylinder and they were all 110-120, not sure what the spec is , but as long as they are all very close that seems OK to me- also did a fuel press check and had about 35 psi- I know on cars most EFI pumps put out 50-60 psi so I was wondering if that might be sufficient- also when I did the fuel press check - fuel came out slightly blue so it appears the oil injection is working, and also I do not have smartcraft gauges- so besides the fuel pump the only other thing it could be is an ignition component- is there anything in particular like a crank sensor that seems to be a common failure with these? any help is greatly appreciated!
Edited by muskymartin67 8/13/2009 4:00 PM
|
|
| |
|
Posts: 1887
Location: syracuse indiana | check the fuel pumps.. my 98 opti did just this and it was the primary fuel pump.. go to bassboatcentral and go to the mercury part and ask sherm what he thinks.. those guys are real good at those motors...bill |
|
| |
|
Posts: 795
Location: Delavan, WI | I tried goin on bass boat central- couldn't find the forum you are talkin about- still tryin to figure out if 35 PSI is adequate pressure ??? |
|
| |
|
Location: Twin Cities | http://bbcboards.zeroforum.com/
http://bbcboards.zeroforum.com/zeroforum?id=53 |
|
| |
|
| did you get it fixed, figure it out?
I hate to sound pessimistic but my 2000 175 EFI did what sounds to be the same thing....and it was shot, dead, kaput...it would have been a ton of money to rebuild so I just opted to bite the bullet and repower it w/ a new 175 Suzi....
|
|
| |
|
Posts: 795
Location: Delavan, WI | After changing the Fuel filter it seemed a little better- did not stay out long enough to figure it out - next step Im putting in a can of seafoam- adding some new gas and changing out the plugs - compression was arounf 110-120 psi per cylinder so it seems the powerhead is OK - I will repost as soon as I test it out again! |
|
| |
|
| Your compression is within Merc Spec. They prefer no more than 10 PSI difference between all 6 holes but 15 is spec. The one I have now is 105-118. It's when they read 25 that you have a serious issue  (Been there once)
You can call Merc and they should be able to tell you what spec is for fuel pressure. I do know that the high pressure fuel pump (Big silver thing on the front Port-side of the motor) suspect you know this being a mechanic, is something that can cause the issue you are having.
Most issues with the larger EFI's revolve around.
1. People not changing their water pump impellor like they should.
2. Not letting that motor warm up before putting the throttle down to bring the boat up on plane. There are two thermostats in that motor, one at the top if each cylinder head, when that motor is warmed up it will start to pee out the indicator hole. Recommend not hammering down until then. Yes, that means you have to wait an additional 2-3 minutes before heading off to the next spot.
2-B. Not running a anti-carbon deposit additive in your fuel. This is HUGE, I'll repeat HUGE with EFI's and today's fuels. One ounce of Merc's Quick-Klean per 6 gallons of gas. Every time you add fuel. Sea foam is NOT the same thing, it's a great product, (I know I ran it through our old dirt-track race motors) but it is not the same as Quick-Klean or Yamaha's Ring-Free. Keep the carbon deposits from building up behind the piston rings (i.e. no stuck/cracked rings) and the motor should not "blow" on you.
3. Some of them had charging system issues. I had one unit that the stator went out in and the same unit had a faulty voltage regulator (there are two of these) that was letting too much through. However this boat was tournament walleye boat before I bought it and I suspect the charging system was being over-taxed on a regular basis. One needs to consider what they hook to the starting battery and then ask the stator to keep up with it!
3. I have found the EFI's to run superior on sythetic oil such as Amsoil or by using the semi-synthetics such as Merc's Optimax oil or one of the other premium brands. Much less smoke, much smoother through the power-band, much cleaner. Inside of my props were spotless when using synthetic oils, no carbon deposits building up at all.
4. There is an oil pump drive gear in EFI's. It is a brass gear and my mechanic told me he has seen a few of those fail but not common. I remove mine and inspect it annually just to make sure it's in good shape.
1. Fuel Additive
2. Let it warm up before putting it down.
3. Change impellor annually or bi-annually on the outside.
4. Regular maintenance to plugs, fuel filters.
5. Synthetic oil.
6. Enjoy years of trouble-free performance.
Good luck. Will be interested to see what you find. |
|
| |
|
Posts: 1095
Location: Hayward, WI | Fuel psi is supposed to be 36-39psi. I don't think the 1 psi difference is your problem. I think that motor has a stator with different windings for low and high speed, sounds like the high speed coils are going. This should be easy to check, just see if you are loosing spark when motor starts to miss. If not loosing spark I would then look at sticking injectors. |
|
| |
|
Posts: 795
Location: Delavan, WI | Looks to be an ignition problem - a friend of mine knows a marine mechanic and after talking to him the problem seems to be a switchbox- my motor has 2 of them - after disconnecting 1 bank the motor did not run- after disconnecting the other- it ran so when its losing power its actually running on 3 cylinders- I ordered em and should have em later this week- found em aftermarket for $108 each-OEM from mercury they are around $200 each so that was a no brainer- hopefully that is it- will post again after I perform repair. |
|
| |
|
Posts: 795
Location: Delavan, WI | Well the boat is finally fixed- in addition to the switch boxes- turns out I had a bad coil on cyl#6 which would drop out intermittently and cause the motor to go into safety mode- thats when it would not go over 2000 RPM- finally get to enjoy driving it the way its suppose to be ! |
|
| |
