'86 90Hp Mariner won't rev up

[CanadianZ]

Hello. This is my first boat so please be patient with me. <br /><br />I have taken it out twice and it hasn't run very well either time. Everything seems fine at idle or if I rev it up in neutral a bit. But on the water under load it down't want to rev up very much and seems like it doesn't have the power it should. <br /><br />I have changed the spark plugs and have checked for spark at each by holding them on the block. <br /><br />I know I should do a compression test, but I want to check a few other things as well.<br /><br />How do I check if the switching boxes are all functioning properly? I know they were replaced in '96 as I have reciepts. (but I guess they still might not be working properly)<br /><br />Any other ideas or suggestions are greatly appreciated.<br /><br />Thanks, CanadianZ

 

[CanadianZ]

Re: '86 90Hp Mariner won't rev up

Also, I noticed it seemed to use a lot of fuel for the short time I was out. Thanks.<br /><br />CanadianZ

 

[The Marine Doctor]

Re: '86 90Hp Mariner won't rev up

Unfortunately the inline 6 product had many things that would cause the same conditions that yours seems to have.<br /><br />Could be as simple as a worn needle and seat...to the seals on the reedblocks not sealing anymore or a blown piston. Its best to see a dealer and let them have a look.<br /><br />What you can do yourself is...check the compression and check the spark in a more reliable way also check for fuel leaking out of the carbs by sqeezing the bulb.<br /><br />TMD

 

[CanadianZ]

Re: '86 90Hp Mariner won't rev up

Thanks, I have done a search of your website and found a few people describing the same symptoms and with many different solutions. I hope it isn't too difficult or expensive for me. <br /><br />I will post as I make progress in determining what the problem is (or isn't) and hopefully I can get some direction. Thanks again for the reply.<br /><br />CanadianZ

 

[CanadianZ]

Re: '86 90Hp Mariner won't rev up

I went out with a friend who knows a bit about boats and he said it sounded like a high speed coil problem. It seems to run fine until about 2500-3000 RPM and then it misses. <br /><br />Does this sound right to anyone?? How hard is this to fix?? <br /><br />Thanks for the help.<br /><br />CanadianZ

 

[greasemonkeyozi]

Re: '86 90Hp Mariner won't rev up

I wouldnt hurt to check the timing. You can use a standard timing gun on most mercs, except, you have to have a shop manual to tell you the settings.

 

[The Marine Doctor]

Re: '86 90Hp Mariner won't rev up

The highspeed coil that you are refering to is the STATOR. One has to have a special puller to remove the flywheel. After that the Stator is easy to replace.<br /><br />TMD

 

[CanadianZ]

Re: '86 90Hp Mariner won't rev up

Yes, I believe I remember him saying somthing about a stator. Sounds like this might be the problem. <br /><br />I will definitley check the timing before I purchase anything. <br /><br />Thanks, very much for all the help.<br /><br />CanadianZ