mercrusier 170 starts missing after using trim

[vinny228]

I just bought this boat, has new coil,points,plugs,dis. cap,rotor, condenser, coil wire, water seperator. After running about 15 min. it starts missing and running rough. Raw water pump is new but don't know about fresh water pump. Seems like it starts when I use the tilt trim switch. Compression is good. Any help!!!!

 

[Don S]

Re: mercrusier 170 starts missing after using trim

Sounds like you have problems with battery connections. You need good solid clean and tight battery connections on both the positive and negative cables. You wouldn't believe the number of starting/running problems I have found to be nothing more than bad cables or loose battery terminals.
While those wingnuts are easy to remove, they cannot be tightened enough with just your fingers. Throw them away, clean the terminals and put some regular nuts on them and tighten with a wrench.
Your problems will probably vanish.

 

[Pst76]

Re: mercrusier 170 starts missing after using trim

Just went through a similar issue on my 470 motor and it ended up being a voltage problem. Cables as well. The charging system was not maintaining charge to the battery so my battery was being drained when I hit the trim and motor would skip. I put in new batteries cleaned all cables and got rid of wingnuts. No problems and my voltage gauge is showing a good steady charge when motor is running.
Good luck

 

[jcohen58]

Re: mercrusier 170 starts missing after using trim

Just went through a similar issue on my 470 motor and it ended up being a voltage problem. Cables as well. The charging system was not maintaining charge to the battery so my battery was being drained when I hit the trim and motor would skip. I put in new batteries cleaned all cables and got rid of wingnuts. No problems and my voltage gauge is showing a good steady charge when motor is running.
Good luck

Hey guys..
I was just about to post a question on a similar souding problem.. what do you think???

The motor 3.0L ( 115 hp?) runs like a top... but sometimes ( seems like early morning or coming back in the late ( moist ) dark many times.. but not always..??) I get the " burp" or missing.. almost stalling feeling.. if I hit the trim and/or hold it a second...

Pst76.. you say "charging system is not maintaining the charge to the battery..." What do you mean?? How do you fix it.. and is that the underlying cause???

I just want to know where to start so I don't rip into it with very limited work time... It's also tough to spot cause it's intermittant...

Thanks for any help you guys can offer...

 

[Don S]

Re: mercrusier 170 starts missing after using trim

Start a new thread with your question jcohen58, otherwise it will get lost when people read only the first post in the thread and reply to it only.

 

[vinny228]

Re: mercrusier 170 starts missing after using trim

Sounds like you have problems with battery connections. You need good solid clean and tight battery connections on both the positive and negative cables. You wouldn't believe the number of starting/running problems I have found to be nothing more than bad cables or loose battery terminals.
While those wingnuts are easy to remove, they cannot be tightened enough with just your fingers. Throw them away, clean the terminals and put some regular nuts on them and tighten with a wrench.
Your problems will probably vanish.

Replaced wing nuts, still does the same thing. Could the voltage regulator be bad and where is it. Just ordered alt. conversion kit. Seems everyone thinks the stator setup stinks. I replaced 100% antifreeze with just water and put layers of electrical tape around coil between coil and bracket, seems like the coil gets to hot. It ran 10-15 min. longer before it started missing. When I hit the trim it makes it a lot worse. If I go out the next day she runs fine ofr awhile then starts acting up.

 

[Don S]

Re: mercrusier 170 starts missing after using trim

Could the voltage regulator be bad and where is it. Just ordered alt. conversion kit. Seems everyone thinks the stator setup stinks.

Obviously you are going for the "Throw parts at it till it works" method of boat repair, usually very expensive and very ineffective.
All you have to do is run the engine at around 1500 rpm and put a volt meter on the batteries and see what the voltage is. The stator setup might not be the best but it did work for a while.
And what is 100% antifreeze thing got to do with it? Is it overheating? Why would you go from 100% to 0%? That doesn't make sense.
Wrapping tape around the coil because it seems to hot to you? Do you know how hot the should be? and if it was too hot, why insulate it with tape, wouldn't you want it to cool down? maybe invent a heat sink for the coil ? ? ? ? ?
Personally I think you need to either get an OEM manual and study it or find someone that understands engines to work on it.

 

[vinny228]

Re: mercrusier 170 starts missing after using trim

Could the voltage regulator be bad and where is it. Just ordered alt. conversion kit. Seems everyone thinks the stator setup stinks.

Obviously you are going for the "Throw parts at it till it works" method of boat repair, usually very expensive and very ineffective.
All you have to do is run the engine at around 1500 rpm and put a volt meter on the batteries and see what the voltage is. The stator setup might not be the best but it did work for a while.
And what is 100% antifreeze thing got to do with it? Is it overheating? Why would you go from 100% to 0%? That doesn't make sense.
Wrapping tape around the coil because it seems to hot to you? Do you know how hot the should be? and if it was too hot, why insulate it with tape, wouldn't you want it to cool down? maybe invent a heat sink for the coil ? ? ? ? ?
Personally I think you need to either get an OEM manual and study it or find someone that understands engines to work on it.

I have not thrown any parts on this motor. All tune-up parts are new. The only thing I have added is a water seperator and checked all settings on plugs,points,dwell,and timing. I read on another site that 100% antifreeze will make engine run hotter. Why waste hours makeing a heat sink when I can stop some of the transfer of heat from the bracket with tape. Just trying to eliminate little things. As far as the stator I would like a better charging system. I have a manual ordered. I have been a outboard mech. for 20yrs. I entered this site for a little help with a I/O that I know little about not to be belittled and looked down on.