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Current Replies for 1985 Mark V Yanmar 1GM diesel
 
question 1985 Mark V Yanmar 1GM diesel (surfj24)
Posted: 6:54:38 pm on 7/15/2011 Modified: Never
 
I was crossing Lake Michigan at full throttle, 3000rmp and about 6knts. when all of a sudden the RPM's dropped like it was going to stall.  I throtlled it down and pulled it out of gear and inspected the engine for anything obvious but found nothing.  Now I get only about 5knts. at full throttle.  Does anyone have any suggestions as to what happened and what I can do about it?

Thanks,

Joe
Wisconsin
K.I.S.S. (keep it simple, stupid)
  Re: 1985 Mark V Yanmar 1GM diesel (ALAN FORD)
Posted: 7:02:58 pm on 7/16/2011 Modified: Never
 
Joe, is your 'full throttle' now giving you only 2500 RPM? If yes, it could be a fuel flow problem. Perhaps some crud broke away in the fuel tank or fuel line and partially plugged the filter? So changing it might solve your problem.

Alan of SMOKE 1984 Mk V 002

  Re: 1985 Mark V Yanmar 1GM diesel (surfj24)
Posted: 1:07:44 pm on 7/16/2011 Modified: Never
 
That's what I kinda figured.  That is was a fuel problem.  It thought I may be putting in too much Yanmar fuel treatment but what you said makes a lot of sense.  The start of the race accross we had 40knt. gusts and 6-8' rollers with 2'-4' waves on top of those.  The boat took quite a pounding as did I because I single handed that race.  Thanks for the info.  That's exactly where I'm gonna start.

Thanks,
Joe
Wisconsin
  Re: 1985 Mark V Yanmar 1GM diesel (surfj24)
Posted: 2:08:01 pm on 8/15/2011 Modified: Never
 
Well, I've replaced the Racor fuel filter with the 2micron(which was on there when I bought the boat), the "on engine" fuel filter and the air filter(wow, glad I did that, it was almost non-existant.)  After bleeding the system with the little lever on the engine and bleeding the Racor with the engine running, I took it out for a spin and it ran better but I was still at 3000rpm and only making 5knts. on calm water.  I took a dive and checked the prop.  All is good there.  Could there be some kind of slippage or resistance going on from the motor back?  Like I said, this happend suddenly, not over time and since then I have consistantly maxed out at 5knts w/3000rpm.  My GPS says I'm doing 6knts. and My Horizon cockpit display has seen better days so I'm suspecting it may be the display unit, but it's too coincidental that I lost that knot right after the "event."  I don't know, the engine runs great, I keep the tank full and use the recommended Yanmar fuel additive, so I guess I'll just have to live with it unless some one has any other suggestions.  I sure would love that extra knot back.  Musta lost it somewhere in the middle of Lake Michigan.  I thought I heard a splash just before the rpms. took a dive and I'm not getting anywhere with Yanmar dealers and the people that work on them.  No response after repeated emails.  Whatever.

Joe Kiehm
K.I.S.S. 1985 Mark V
Hull #531
Glendale, WI.
  Re: 1985 Mark V Yanmar 1GM diesel (JWente)
Posted: 9:43:27 pm on 8/15/2011 Modified: Never
 
if your GPS says you're going 6 knotes then you are going hull speed - why worry?
you might want to adjust that knot meter.
jim
  Re: 1985 Mark V Yanmar 1GM diesel (surfj24)
Posted: 11:19:09 pm on 8/15/2011 Modified: Never
 
I think I'm going to REPLACE the knotmeter.  Also, after several hours of it being on, it starts to fade in and out.  I think it's time for a new one.  Yea, I think I'm doing fine with the engine.  I think all of those things just needed to be replaced and the choppy seas at the start of that race probably started something floating around in the system, or it was my air filter trying to burn thru the engine.  Wow, there was hardly anything left of it but the screen.  Thanks for the reply.

Joe Kiehm
K.I.S.S.
Hull #531
Glendale, WI
  Re: 1985 Mark V Yanmar 1GM diesel (ALAN FORD)
Posted: 9:58:28 pm on 8/19/2011 Modified: Never
 
Joe, before you replace the whole thing it might be an idea to check the little spinning propellor beasty. I take my boat out for a clean 3 times each season, and the spinner ( I'm sure it has a more technical name....) always looks like a hedgehog. It's some evil sort of growth that attaches itself to the plastic. I clean it off and gain at least 2 knots each time!!!!! I don't cover it with VC17 as that would mess up the flow, but there must be a product that repells the growth for a couple of months? Anyone help us please?

Alan of SMOKE 1984 Mk V 002

  Re: 1985 Mark V Yanmar 1GM diesel (surfj24)
Posted: 1:13:11 pm on 8/20/2011 Modified: 1:18:58 pm on 8/20/2011
 
Yea I was suspect about that as well but I won't know until I pull the boat for the season.  I'm thinking it's either growth or maybe a broken paddle/s.  It could be that simple.  I returned the TACKTICK wireless-solar powered unit.  Never buy from a distributer.  They'll tell you anything you want to hear.  I went to TACKTICK and got the whole scoop.  $535 for the basic dual display(speed/depth) was just the start.  But they don't tell you that and when you find yourself out of the ballpark pricewise, they nail you with a 5% restocking fee.  I cut my costs and I'll work with what I have.  The only thing that confuses me is that it happened at the same time the rpms. dropped to nothing.  that was 1 and a half months ago and the speed and rpms have been consistantly at 5knts. 3000rmp ever since.  What does a sudden drop in rpms. have to do with the boat speed display?  Coincidence?  I don't know, I'v run out of ideas accept for working with the display unit and it's components.

Thanks,
Joe Kiehm
K.I.S.S. Hull#531
Glendale, WI.
  Re: 1985 Mark V Yanmar 1GM diesel (ALAN FORD)
Posted: 8:57:11 pm on 8/20/2011 Modified: Never
 
A bit of additional internet hunting tells me that the spinner should be an 'impeller' or perhaps a 'paddle wheel'.  There are suggestions that lanolin deters the marine hedgehog growth, and a good bath in vinegar kills it if you are too late with the lanolin.

Alan of SMOKE 1984 Mk V 002

  Re: 1985 Mark V Yanmar 1GM diesel (CRouse)
Posted: 12:25:22 pm on 10/28/2011 Modified: Never
 
I know it is a bit late in the season, but I just got my motor "fixed".  I had the same problem - suddenly the 1GM10 on my 27' Mark V went from 3600 to 2800 = 6 knots to 5 knots.  I changed out everything also (filters & fuel) and bled the system until my fingers hurt.  No change.  Then I invested in a mechanic from Annapolis. He diagnosed the problem as dirty fuel injector.  He pulled that out in 5 minutes, and within 10 minutes, he cleaned it and put in back in.  The engine went right back to 3600 rpm and 6 knots!  The injector was not "bad", but dirty enough to be cleaned/ adjusted.  Now the engine is more quiet and runs more smoothe.

Charlie Rouse,
Gemini, Mark V #329