30 hp Mariner (Yamaha) year?

[boatbum]

I'm sure you get tired of searching for year models. I have checked the link on marinshopen.se, but I still can't find my serial number. Maybe I'm not reading it correctly. I have a 30 AM 689 S 001653. I appreciate your help.

 

[Paul Moir]

Re: 30 hp Mariner (Yamaha) year?

It seems to come out as 1979 engine. Does that seem right to you?<br /><br />The 689 is a dead giveaway for a Yamaha built mariner engine, by the way.

 

[boatbum]

Re: 30 hp Mariner (Yamaha) year?

Thanks for the reply. I don't know if '79 sounds right or not. (that's how clueless I am about the motor) I currently run an Evinrude 9.5 - 1965 model. I want to find parts for the Mariner and I can't seem to find a starting place. The compression reading is 65 - 68 on both cylinders. Will a new ring job do it?

 

[dilligafda]

Re: 30 hp Mariner (Yamaha) year?

I'm showing it to be a 1980. as far as the rings go, have you checked to see if they are coked up and stuck? Has the engine been sitting for a long time? You could try to put some Seafoam or Powertune in the cylinders to loosen up the rings and run the compression test again.<br /><br />Good luck and keep us posted!

 

[dcm3372]

Re: 30 hp Mariner (Yamaha) year?

Hi,<br /><br />I have a 30HP Mariner 30AM 689 Year 'S' (sn 004805) which I've had quite a while now.<br /><br />I'm positive mine is a 1980 engine, I've always stated 1980 when ordering parts and catalogues - and it sounds to me like yours is too.<br /><br />They are indeed Yamaha built motors - and good ones too I've been very please with mine

 

[boatbum]

Re: 30 hp Mariner (Yamaha) year?

Thank you Dan Moore and dilligaf for your responses. I will try the SeaFoam or Powertune and see if that improves the compression reading. I got the motor from someone and it sat for awhile. Nothing is locked up, but you can tell the compression is low by the lack of resistance when you pull the starter cord. I sure would like to get this thing running. Thanks for the confirmation on the year model. I'll let you know if the cylinder treatment works. Thanks again.

 

[boatbum]

Re: 30 hp Mariner (Yamaha) year?

I forgot to add one thing. Can you tell how many rings are on each piston (1, 2, or 3)by the serial number? Or do you roll up your sleeves and get in there? I'm trying to price parts, but I don't know what I have. By the way, I'm blown away at how cool this site is.

 

[BF]

Re: 30 hp Mariner (Yamaha) year?

hiya,<br /><br />you should use a gauge to check compression, not the "rope feel" method. I've had several rope-start engines of assorted types that were relatively easier to pull over than others, and yet still had good compression. Also, if is somewhat low, you'll see to what degree the decarb helped. <br /><br />as a "field test" way of crudely checking compression when you don't have a gauge, remove spark plugs had try and hold your thumb over the spark plug hole as the engine is turned over. You shouldn't be able to do it.... if you can you have either no, or very low compression (e.g. broken ring, or hole through piston). Then you'd need to do more than a decarb.<br /><br />that's my $.02<br /><br />Brent

 

[BF]

Re: 30 hp Mariner (Yamaha) year?

oops, saw your compression readings after the fact... does your gauge read higher on another motor? have you had this one running?<br /><br />Brent

 

[dcm3372]

Re: 30 hp Mariner (Yamaha) year?

Could I make a recommendation here - buy the workshop service manual. They really are worth their weight in gold and you can study a job before undertaking it.<br /><br />Also - check this link :<br /><br /> http://www.mercruiserparts.com/selectDocs.asp?doc_nbr=+84952 <br /><br />It shows 2 rings per piston on there. mercruiserparts.com is also an invaluable resource - I've printed the whole lot out for my engine and made a parts catalog.