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Re: 6.5 mcck Onan
Posted: Mon Jul 08, 2013 10:12 pm
by Big D
Larry, where did you get it and how much?
Re: 6.5 mcck Onan
Posted: Tue Jul 09, 2013 12:05 am
by Commissionpoint
larryeddington wrote:I am now in possession of a brand new Mcck bimetallic choke pull off spring and insulating disks. Installed on carby, Wed will give it a run on the genny.
Very nice Larry. Hopefully this solves the choke problem.
Man, that thing is gonna be good as new when you are done. Real nice thing about that is, once you have taken the time to get an old Onan in good shape it will likely run well a long time for you.
Re: 6.5 mcck Onan
Posted: Fri Jul 12, 2013 5:58 pm
by larryeddington
New bimetallic chock spring installed with insulating disks. Spring $175 and disks were $18 for both. The infernal Onan mcck 6.5 works perfectly and carries AC and Refrigerator load. Did not try anything else as have some wiring gremlins. I set the RPM at 1802 (close as I could get it to 1800) and pumps out 120 volt current, quietly and "efficiently" does anyone know the fuel burn average for this Genny.
Also my raw water cooling pump remanufactured to my specs works perfectly, no overheating etc.
Now on to the next chore, packing glands.
Got the choke parts off of ebay, if anybody wants it I have his email address, it got a little confusing as he uses three aliases on ebay but cost was as above.
I also have points, plugs and condenser but not going to use them now as it is just purring as it should, oh yes before anybody asks I have two carbon monoxide alert devices in living areas.
Re: 6.5 mcck Onan
Posted: Fri Jul 12, 2013 7:52 pm
by larryeddington
another oops
Re: 6.5 mcck Onan
Posted: Sun Jul 14, 2013 9:08 am
by Big D
Speaking of CO, the nipple coming off the exhaust manifold was reponsible for a few deaths on Onans and Kohlers which precipitaed service bulletins after lawsuites years ago. They rusted from the inside out releasing exhaust gases that eventually made their way into living spaces. The nipple was changed to a stainless steel one to correct the issue and last I looked was still available even from Cummins. Everyone should take a look at what they have and ensure it's the updated SS part. I suspect most out there aren't
Re: 6.5 mcck Onan
Posted: Sun Jul 14, 2013 11:06 am
by larryeddington
Thanks, and mine is one of them. I researched and found the only data on Kohler a lawsuit from Lake of the Ozarks Missouri regarding the nipple and nothing on Onans. However that said I am going to examine mine. Rather than using stainless I will use brass or bronze, as according to the Kohler suit it was originally. The problems seems to be just the nipple connector and not the water injection piece. the Nipple is 1.25 inch NPT.
Re: 6.5 mcck Onan
Posted: Mon Jul 15, 2013 8:02 am
by aaronbocknek
interesting thread. my mcck has the stainless reducer, i believe the PO put it on. a year and a half ago i also had the exhaust mixer replaced as the original one began to decompose, yes, from the inside out. mostly these old onans go bad from lack of use. i run mine once a week during the season at a 50% load for about an hour. the gph, according to my spec sheet is ''1.0gph (3.8L) at full load'' (as an fyi, cooling flow is rated at 4 gallons (15L) per minute.)
in regard to the co2 (correction to CO due to early hour 
) deaths. onan was not as proactive at retrofitting their gensets compared to kohler. with kohler, it was the attach point and the mixer jet. (kohler speak) shortly after dad had bubala 3 trucked to oceanside, ca, he read an article about the co2 deaths (correction to CO due to early hour ) and contacted kohler directly. once it was determined that his model genset was eligible for the retrofit to the stainless steel mixer system, a rep from kohler flew to san diego, replaced the part and did not charge dad. this was all done at kohler's expense.
Re: 6.5 mcck Onan
Posted: Mon Jul 15, 2013 9:42 pm
by Big D
larryeddington wrote:....The problems seems to be just the nipple connector and not the water injection piece.....
Yes just the nipple piece only. The replacement is stainless. Not sure why they went with that and not brass etc. but I'm sure the metal to use as a replacement was given some careful consideration after the lawsuits so I've stuck with the stainless replacements. Sticking with the recommended metal also looks after the liability issue.
Aaron, it's CO not CO2
Re: 6.5 mcck Onan
Posted: Tue Jul 16, 2013 3:53 am
by aaronbocknek
Big D wrote:larryeddington wrote:....The problems seems to be just the nipple connector and not the water injection piece.....
Yes just the nipple piece only. The replacement is stainless. Not sure why they went with that and not brass etc. but I'm sure the metal to use as a replacement was given some careful consideration after the lawsuits so I've stuck with the stainless replacements. Sticking with the recommended metal also looks after the liability issue.
Aaron, it's CO not CO2
can i claim chemo brain and the early posting hour on the time stamp or either one? i feel like a fool on that one. simple screw ups like that really torque my screws. sorry fellas. i gets really frustrating at times. anyway, the exhaust mixer, or, water injection assembly (onan part 155-1058 (some catalog it with the 'leading zero' before 155) ELBOW, EXHAUST WITH INJECTOR PORT) can and does 'rot' out. it's mostly from lack of use, but the one on my f-32 was pretty nasty and the one on my tri cabin completely fell apart prior to winterizing in 2011. i had it replaced by john my mechanic in less than a week. he's really good at finding onan parts that do not cost a whole lot, and yes, this one is not a knock off. it has the internal onan casting stamp. i just wish it was made of stainless instead iron. at least i think it's iron.
Re: 6.5 mcck Onan
Posted: Tue Jul 16, 2013 8:05 pm
by larryeddington
Well my Onan mcck 6.5 seems to start and do what it does as it should. We looked at frequency of voltage and it is normally around 58 to 61 HZ close enough for government work. The only thing we did not load on it was the hot water heater and we have not tested it.
Checked the nipple on this unit and it is in fact the stainless one so good there.
Another question my inside start switch for the onan is mounted under a device that is made by general electric, is black plastic or bakealite, has two old screw in fuses you can see when open up, and when closed it can be slid right or left like a switch or disconnect which is what I think it was. I say was because I find no voltage on it. Any ever seen one before? Sorry I did not take a picture.