1981 6.5 onan generator

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fpawn
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1981 6.5 onan generator

Post by fpawn » Sat Aug 03, 2019 7:07 pm

I need some opinions. I have 1981 F32 with 6.5 onan generator which has not worked in 2 years. Until than worked. I have some one is willing to service and rebuild it over the winter if I haul it out. Am I nuts???? i was thinking if I go forward with the repair at least I would not have to change the electric panels and fuses. What would you do???

zbigk
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Re: 1981 6.5 onan generator

Post by zbigk » Sat Aug 03, 2019 7:49 pm

After many years of spending money to fix out 1982 Onan, i finally had enough and in 2014 replaced it with a Westerbeke 6.5 MCG-614. We spend approx. 40-45 nights anchored each season and I was in the bilge constantly keeping trying the Onan running. This has worked out great.

Good luck.
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prowlersfish
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Re: 1981 6.5 onan generator

Post by prowlersfish » Sun Aug 04, 2019 10:00 am

The question is what is wrong with it ? what went wrong with it 2 years ago and what went wrong while it was sitting ? Cost vs new ?
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El L Sea
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Re: 1981 6.5 onan generator

Post by El L Sea » Sun Aug 04, 2019 2:23 pm

We dumped our Onan shortly after we bought the boat and it crapped out. We went with a Westerbeke 7.6 EGTD. We run it probably 300 hours a year.
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captainmaniac
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Re: 1981 6.5 onan generator

Post by captainmaniac » Mon Aug 05, 2019 12:45 am

I’m with prowlersfish... start with understanding what is wrong with it to figure out most cost effective way forward.

fpawn
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Re: 1981 6.5 onan generator

Post by fpawn » Mon Aug 05, 2019 8:03 pm

last time had it running, it was not pumping water well. I had change the impeller the year before and did notice water pumping was very dark, Thats all I remember about last time used. I know the parts are expensive so dont know what I am getting into

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Re: 1981 6.5 onan generator

Post by scct54 » Mon Aug 05, 2019 11:39 pm

I have had 2 of these sets. I have an 81 in my tricabin. The exhaust elbow failed sunday, ordered a new one for 250. Ordered a new impeller for 38 delivered, was on back order for weeks. I have spare parts as new parts are no longer made. You can get tune up parts,but if you need a new water pump,good luck. I bought a stator for one in 96, it cost 1200. plus having it pro installed. The engine side isn't bad if you have the manuals and engine skills. The electric side is tough. A new modern genset would be my choice,but i'm keeping my o_no genset going as long as i can.

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Re: 1981 6.5 onan generator

Post by RWS » Tue Aug 06, 2019 6:03 am

If you are going to replace it - it must come out.

If your guy is going to repair it - as you said, it must come out.

These units have become the albatross

I was told they were taken out of production and due to several carbon monoxide deaths and the lawsuits that followed. Replacement parts were made unavailable in order to reduce the number of potential future liabilities.

At least that's what I heard.

Anyway, these units have a history of working well, up to a point.

The tipping point is the ongoing cost & reliability factor.

Should you choose to repair the Onan, whether you spend $300 or $3,000 in repairs, at the end of the day if something major goes wrong, that repair is wasted time, money & effort.

Marine gensets have come a long, long way over the last 40 years.

Here in Florida, we can boat all year long and we rely on the genny for the fridges, battery charger, icemaker and air conditioning.

It is as important to our experience as are the main engines.

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El L Sea
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Re: 1981 6.5 onan generator

Post by El L Sea » Tue Aug 06, 2019 8:22 am

RWS wrote:
Tue Aug 06, 2019 6:03 am


Marine gensets have come a long, long way over the last 40 years.

Here in Florida, we can boat all year long and we rely on the genny for the fridges, battery charger, icemaker and air conditioning.

It is as important to our experience as are the main engines.

RWS

I agree. For us:

No Generator = No Trip
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Big D
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Re: 1981 6.5 onan generator

Post by Big D » Mon Aug 12, 2019 11:11 am

The Onan (and Kohler) carbon monoxide problem was due to an OEM steel nipple between the manifold and elbow. It would rot from the inside out so it wasn't noticeable, and when it finally failed, you'd get CO in the cabin. A bulletin was issued by both manufacturers with the recommendation to replace said nipple with a new part number which was a stainless steel one. Of course just because a safety bulletin is issued doesn't mean owners follow through and act on the remedy, or that retailers, marinas, etc. follow up with their customers.

The Onan MCCK has always and continues to be a robust workhorse. After all these years, the non-marine versions are still out there being used as back-up generators in some industries because of their reliability. Do they fail, of course they do, what doesn't? Their biggest problem as with any generator or substantial hardware their age is that they haven't gotten used nearly as much as they should be. That kills any engine, generator, etc. before their time. Yes parts are more difficult to get now but they're still out there and they are expensive when you find them. When properly set up, repaired, maintained, and run often, they run fine and will likely still outlast some of the newer stuff on the market today. Would love to see how those run in 50 years!

From a practical standpoint, one has to weigh the pros and cons; parts availability, their cost, age, etc. vs a newer unit but don't condemn Onan MCCKs in general because you haven't had one that worked right. If that's the case, it's simply likely it hasn't been repaired properly. There are fewer and fewer people that are familiar with them/old equipment in general but that's indicative of today's techs; if you can't hook up a diagnostic computer to it then they have no clue, but that's another topic.

Are you better off putting a couple of thousand into a newer unit vs an older one, one would think so but we all know things just aren't built the same anymore so one must consider that. Bottom line, your gut and wallet will dictate which route you take.

If the unit runs and generates power but is having a cooling issue, replacing the entire unit would be the last thing on my mind. Black water in the exhaust is carbon and likely from running rich which is typical at startup and what's collected in the muffler from her last run. Fix the cooling issue and do a tune-up, then decide if she needs replacing or not.
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Re: 1981 6.5 onan generator

Post by P-Dogg » Mon Aug 12, 2019 7:32 pm

Amen Big D.
I needed a less expensive hobby, so I bought a boat!

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prowlersfish
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Re: 1981 6.5 onan generator

Post by prowlersfish » Mon Aug 12, 2019 9:53 pm

Very well Put Big D and so very true .
TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat :D
2009 TROJAN RENDEZVOUS
Port Kinsale 2010 & 2011. Solomons get together 2011.

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