Onan 7.5 Gen set

Big D · Post by **Big D** » Mon Dec 17, 2012 10:05 pm

prowlersfish wrote:Big D , On the recall I was not aware onan had one on the exhust . I Do Know kohler had one with that issue .

http://my.boatus.com/consumer/Kohler.asp

Paul, I saw that one before. I have an Onan paper on the Onan issue but if you read yours part way down, it talks about the Onan issue also. The Onan issue was brought up in the Kohler lawsuites. It also mentions the Onan fatalities.

RWS · Post by **RWS** » Tue Dec 18, 2012 6:03 am

As I recall, My 10 Meter came with a factory installed Onan 6.5 MCCK generator, so you are in th eright spot with this one.

Seriously, get TWO CARBON MONOXIDE DETECTORS
One for the fwd cabin and one for the salon.

Change your batteries twice a year.

This is serious stuff !

RWS

guglielmo6160 · Post by **guglielmo6160** » Tue Dec 18, 2012 6:28 am

I found impellers for the raw pump on ebay,, does anyone know where else I may find em>
RWS,, are there any places in our area that may service these units?

RWS · Post by **RWS** » Tue Dec 18, 2012 6:34 am

bought my parts from an onan dealer while in Ft Lauderdale.

Since I do all my own work, I do not know of any dealers in the area.

By the way, nice find on that genny !

A bit of oxalic acid will reduce a good bit of the rust before you paint.

RWS

guglielmo6160 · Post by **guglielmo6160** » Tue Dec 18, 2012 10:01 am

thanks
I had it running today for over 3 hours in the back of my pickup truck, using a hose of course, runs fine, I still have that issue with the rocker switch , but I was able to bypass it for now, until I get to the bottom of it. Amazing how quiet it is
I do most work myself as well, but I still need parts, so Lauderdale is do able for parts I guess.
I already ordered an impeller from ebay , actually two of them, as a spare
but I still need the exhaust elbow with sensor etc,

Commissionpoint · Post by **Commissionpoint** » Tue Dec 18, 2012 10:12 am

So, what parts have you been ordering? I don't mean the names of the actual parts, but what are they parts for? If you don't know what year and spec that 6.5 MCCK is you are likely to end up with a whole bunch of parts that are absolutely no good to you whatsoever. Its not like a small block Chevy where you can use parts over a 40 year range and still get results. Even down to impellers there are at least two if not three choices for the MCCK. Knowing which one you actually need is going to save you a lot of time and frustration.

hmc · Post by **hmc** » Tue Dec 18, 2012 12:31 pm

i THINK ITS A 7.5 NOT 6.5 SEE POST 1

guglielmo6160 · Post by **guglielmo6160** » Tue Dec 18, 2012 1:19 pm

so far all I ordered is an impeller, going strictly by the dimensions, as I have the old one.The 12 volt start relay/solenoid is generic and they had one at west marine, and the rocker switch as well. Those parts do not have to be specific to this generator

as far as other items,(exhaust elbow, diodes, etc,, I am waiting to get all the info I can before I order,
and yes it is a 7.5

guglielmo6160 · Post by **guglielmo6160** » Tue Dec 18, 2012 1:23 pm

so far all I ordered is an impeller, going strictly by the dimensions, as I have the old one.The 12 volt start relay/solenoid is generic and they had one at west marine, and the rocker switch as well. Those parts do not have to be specific to this generator

as far as other items,(exhaust elbow, diodes, etc,, I am waiting to get all the info I can before I order,
and yes it is a 7.5

Commissionpoint · Post by **Commissionpoint** » Tue Dec 18, 2012 4:09 pm

hmc wrote:i THINK ITS A 7.5 NOT 6.5 SEE POST 1

I don't think so. Its either 4 or 6 1/2 kw. Most likely 6 1/2. Only 1 sorta ok pic and I can tell you that. Its a 2 cyl horizontally opposed gas engine.

Lets get a serial number off of it and see how close I got with my guess of 1982 6.5MCCK Spec J. If I was really off on that guess beers are on me. Sound fair?

guglielmo6160 · Post by **guglielmo6160** » Tue Dec 18, 2012 5:30 pm

well,, it was sold to me as a 7.5,,, but we all know how that goes. I will try to get some numbrs off this thing tonight.

aaronbocknek · Post by **aaronbocknek** » Tue Dec 18, 2012 6:16 pm

i might be stepping on a land mine here, but i've been quietly watching this thread from the distance from day one. btw... mazel tov on the good buy on this beast. properly taken care of, they last a long time, but, keeping it idle and not running it absolutely KILLS them. they are meant to be run and not act like a paper weight in the bilge. i run mine once a week for 45 minutes with a 50% load on it. keeps the scmutz from accumulating and it's good for the stator and windings. the thermostats are a breeze to change having done them on not one, but two of these (my f32 and the tri) also, i do a mary kate on and off internal 'bath' twice a season to keep the critters from building up inside the water jacket. as for the elbow, i have a link for you. the price is not bad. you will have to get a stainless reducer for the manifold to the elbow (i had mine retro fitted along with a new elbow as mine split just before the end of the season last year). as for the KW for yours. i believe that onan only made a 4 and a 6.5kw in gas and the 7.5 was diesel. keep us posted on the reconditioning of this. btw... how in the heck did you find this anyway?

link for the onan elbow... (part # is 155-1058, however, some use a leading 0 in front of the first number) hope this helps.

aaron

http://onanparts.com/index.php?main_pag ... cts_id=425

guglielmo6160 · Post by **guglielmo6160** » Tue Dec 18, 2012 6:23 pm

ok, I just spent about a half hour going over every inch of the gen, and I can't find anything. all I have is a wiring diagram thats says
"schematidc 98-3448" thats it, thats drawn on the back of the cover plate. There is an area that looks like it may have had a plate there at some point.
maybe when I strip it down to blast the paint off , I will see something.

guglielmo6160 · Post by **guglielmo6160** » Tue Dec 18, 2012 6:26 pm

Aaron, thanks for the good info, I already checked this link and see that the fitting looks alot like the one I have now, I was under the impression it was an updated piece. Seems it is made of cast iron? is that right? I thought it would be SS with a sensor for overheating .

I believe it is a 6.5, not a 7.5 as the seller told me. I found it at a garage sale, believe it or not,,lol.
It runs great, just have a few bugs to work out, nothing horrible. So you have one of these?

aaronbocknek · Post by **aaronbocknek** » Tue Dec 18, 2012 6:44 pm

guglielmo6160 wrote:Aaron, thanks for the good info, I believe it is a 6.5, not a 7.5 as the seller told me. I found it at a garage sale, believe it or not,,lol.
It runs great, just have a few bugs to work out, nothing horrible. So you have one of these?

you are welcome. i've worked on the one on my old f-32 and the one on my tri cabin. personally, i HATE them. the tri i grew up on had a custom installed kohler 7.5kw that ran anything we threw at it. and yes, kohler actually flew a tech out to san diego where she was relocated in 1996 to retrofit the new stainless exhaust elbow. i find onans not the most DIY friendly genset. but, properly cared for, they do last a long time. very proven design. give me a kohler or westerbeke any day. the governors on the mcck can be really tricky when they begin to hunt.

i've replaced thermostats on both gensets, and, i suggest you do it to yours too. they are small and can stick easily. don't forget the gasket kit too.... here you go.... thermostats and gasket kits...

http://onanparts.com/index.php?main_pag ... cts_id=475

http://onanparts.com/index.php?main_pag ... cts_id=127

while yours is in the rehab process, i suggest you do a mary kate on and off flush before you install it in the boat, and after you installed the new thermostats. simply pour some on and off in a funnel attached to the water pump hose. fill the funnel, toggle the switch to suck the fluid into the water jacket. do this for half the bottle. let the generator sit for about a half an hour then empty the rest of the bottle using the same toggle technique, and let that sit for about 10 minutes. once this is done, start the generator and watch the crap flow out the exhaust. stand clear because the discharge can be caustic and will also have decomposed sea critters and any loose rust in it. let it run for about an hour to finish the flushing process. you will be amazed at how much cooler the unit runs.

my mechanic john taught me this and i swear by it.

aaron