Kohler Gen Set - Reduced Volts

[Art]

Btw I keep a KillAWatt monitor plugged into a handy outlet to monitor gen voltage and frequency. Excellent and only about $30.

Archie, TY for input. As this is first time I've had gen set problem... will now purchase several items to keep better eye on things.

 

[sbu22]

Thanks, sb! I opened the link. Looks like really good Kohler parts opportunity, general input too. Will contact them. - Cheers! Art

PS: If yours too is gas engine... is there hour meter on yours? Not on mine... just wondering how long these baby's run. So far [during 10 yr. ownership]the engine is perfect. We don't put too many hrs. on it. Don't think the PO [original] owner did either. The more I get into this the more I am feeling the low voltage problem will get cleared up.

The Hobbs indicates 1100+ - it gets used lightly since I've owned the boat. It's gas.

Chanced to run into the mechanic that has been working on the boat for the last decade or so - he's 75 and has been marine wrenching since high school. Echoed Ski and others advice to a T.

Told me that he had, before my tenure, done the rpm adjust to fix voltage low output problem on mine. These gensets apparently powered half the small trawlers in this part of the world back in the day. His opinion is the old Kohler's, with good PM, will out last the boat.

If I had to replace it, I'm thinking a Honda 6500eu. Where I stand now, I'm delighted with my Planet of the Apes, low tech, nearly bulletproof genset.

 

[Art]

The Hobbs indicates 1100+ - it gets used lightly since I've owned the boat. It's gas.

Chanced to run into the mechanic that has been working on the boat for the last decade or so - he's 75 and has been marine wrenching since high school. Echoed Ski and others advice to a T.

Told me that he had, before my tenure, done the rpm adjust to fix voltage low output problem on mine. These gensets apparently powered half the small trawlers in this part of the world back in the day. His opinion is the old Kohler's, with good PM, will out last the boat.

If I had to replace it, I'm thinking a Honda 6500eu. Where I stand now, I'm delighted with my Planet of the Apes, low tech, nearly bulletproof genset.

Thanks, sb. Plan to report good results in near future.

 

[sbu22]

BTW, Art - when my mech said small trawlers, he was referring to working boats, not rec boats - Lafitte skiffs - shrimpers and crabbers. The old gas Kohlers were very much "equipment" and not accessories.

Reminiscent of the F head 4 banger in my 60 Willys - simple, sloppy, and uber reliable.

Let us know how it resolves.

 

[Art]

BTW, Art - when my mech said small trawlers, he was referring to working boats, not rec boats - Lafitte skiffs - shrimpers and crabbers. The old gas Kohlers were very much "equipment" and not accessories.

Reminiscent of the F head 4 banger in my 60 Willys - simple, sloppy, and uber reliable.

Let us know how it resolves.

Planning to! May be a while though. Now that I've gained so much info about this year/model Kohler... I'm fairly confident good resolution will result.

 

[Art]

OK!!!

Said I'd report resolution... so, here it is:

New plugs and new governor spring raised engine rpm to 1800 and hertz to 69.5. Now voltage and amps are in line and all is well again for our 1977 Kohler 7.5 kW gen set!

Simple!

 

[sbu22]

Fantastic! Like General Sherman (William Tecumseh) said: No news is so good or so bad as it first seems.

 

[Art]

I again say thanks to all for support and assistance!!

 

[foggysail]

OK!!!

Said I'd report resolution... so, here it is:

New plugs and new governor spring raised engine rpm to 1800 and hertz to 69.5. Now voltage and amps are in line and all is well again for our 1977 Kohler 7.5 kW gen set!

Simple!

No, no, no, IF your RPM is 1800, the output frequency is 60Hz so something is wrong with your measurement. The RPM is the decision maker for output frequency. This can be important for things such as microwave ovens which are very frequency sensitive.

I have the same genny and absolutely love it but again there are problems and I do mean real problems getting parts. For example, your heat exchanger end plate has a corrosion problem and mine rotted out. A company in North Carolina was re-manufacturing them for $300 which I attempted to order. Gave up after a two month wait so I had one made in a weld shop. I have no clue how long this is going to last because it is made of steel rather than cast iron. OH cost was $300 and the mounting surface was not even flat.

Somewhere you mentioned that you thought the genny was for an RV. Maybe part of it was but your engine looks to be raw water cooled and RVs don’t have raw water available.

The most impressive thing about this machine is that it operates at 1800 and not screaming 3600 RPM. If at any time you are forced to replace your great generator try to find another that operates again at 1800.

 

[foggysail]

AND A WARNING!!!! Be VERY careful to make sure your spark plug wires from the magneto to the plugs NEVER fall off while the machine is running. I found out the hard way. I started the genny to operate my davit crane and while outside on deck I noticed the exhaust didn’t sound right. I immediately knew there must be a plug wire off and did my best to get to it as quickly as possible.

Wasn’t fast enough! By the time I got there I had no spark anywhere. The high voltage pulse transformer in the magneto croaked. A magneto will try to output an infinite voltage and is limited by whatever voltage the spark plug arcs at which will be around 20-25KV.

Took me awhile to repair the magneto. That beast or at least most of that beast is used in other antique machines so they are available...try Ebay. Unfortunately repairing one of these things is usually beyond the capacity of most guys so be careful

 

[Art]

No, no, no, IF your RPM is 1800, the output frequency is 60Hz so something is wrong with your measurement. The RPM is the decision maker for output frequency. This can be important for things such as microwave ovens which are very frequency sensitive.

I have the same genny and absolutely love it but again there are problems and I do mean real problems getting parts. For example, your heat exchanger end plate has a corrosion problem and mine rotted out. A company in North Carolina was re-manufacturing them for $300 which I attempted to order. Gave up after a two month wait so I had one made in a weld shop. I have no clue how long this is going to last because it is made of steel rather than cast iron. OH cost was $300 and the mounting surface was not even flat.

Somewhere you mentioned that you thought the genny was for an RV. Maybe part of it was but your engine looks to be raw water cooled and RVs don’t have raw water available.

The most impressive thing about this machine is that it operates at 1800 and not screaming 3600 RPM. If at any time you are forced to replace your great generator try to find another that operates again at 1800.

Yes, 1800 rpm with 60.5. not 69.5 hertz... my mistake!

There had been a time when Kohler set up new model and serial #'s to "better" differentiate between marine and RV gen sets. Confusion occurred; numbers got too often jumbled on plates for about a year; just happens ours was during that mess. It is surely a marine generator.

At 1800 rpm she is a quiet pleasure to use. Heat exchanger seems to be doing well; we're in fresh water for last 9 years.

Thanks for your concern and in-put!

 

[Art]

AND A WARNING!!!! Be VERY careful to make sure your spark plug wires from the magneto to the plugs NEVER fall off while the machine is running. I found out the hard way. I started the genny to operate my davit crane and while outside on deck I noticed the exhaust didn’t sound right. I immediately knew there must be a plug wire off and did my best to get to it as quickly as possible.

Wasn’t fast enough! By the time I got there I had no spark anywhere. The high voltage pulse transformer in the magneto croaked. A magneto will try to output an infinite voltage and is limited by whatever voltage the spark plug arcs at which will be around 20-25KV.

Took me awhile to repair the magneto. That beast or at least most of that beast is used in other antique machines so they are available...try Ebay. Unfortunately repairing one of these things is usually beyond the capacity of most guys so be careful

Noted! - TY!!

 

[foggysail]

You are fortunate that you’re in fresh water!!! The end plate that I mentioned allows raw water to enter the cooling tubes and leave them after cooling the machine’s internal cooling system. I found my problem when I was having an overheating problem indicating the tubes were plugged.

I was able to clean the tubes by rodding but when I went to install the end plate it just about crumbled in my hands.... the internal sections

Art—- I really wish you the best of luck with your genny! I wish Koehler was still making them, magneto and all.


EDIT: Where did you find that governor spring? I looked for one for a friend and could not find it. What I was going to do was get a regular spring with the same wire diameter and cut it so it has the same number of sections and hope it would have the same Hook’s tension (Hook’s spring coefficient )

 

[Art]

You are fortunate that you’re in fresh water!!! The end plate that I mentioned allows raw water to enter the cooling tubes and leave them after cooling the machine’s internal cooling system. I found my problem when I was having an overheating problem indicating the tubes were plugged.

I was able to clean the tubes by rodding but when I went to install the end plate it just about crumbled in my hands.... the internal sections

Art—- I really wish you the best of luck with your genny! I wish Koehler was still making them, magneto and all.

About 6 yrs ago I saw a Kohler just like ours for sale at very reasonable price [on Craigslist; I think}. As I recall it was said to be in good condition. Guess I should have purchased??!! But, who wants an unproven multi hundred pound hunk of iron hanging around... guess my decision was correct. Time will tell...

 

[Art]

EDIT: Where did you find that governor spring? I looked for one for a friend and could not find it. What I was going to do was get a regular spring with the same wire diameter and cut it so it has the same number of sections and hope it would have the same Hook’s tension (Hook’s spring coefficient )

Forget the fellows name... already transferred note papers regarding this to boat 100 miles away.

Old fellow in a family back east that was Kohler dealer. When Kohler stopped building type gen set we're speaking about he purchased entire OEM parts stock from Kohler. He is who really set me straight on what to do regarding the low voltage and other items we were experiencing. I purchased new governor spring and carburetor rebuild kit. He said it was the last governor spring and 5th to last carb rebuild kit.

I'll try to locate his name and connection data.

 

[BIG CAT]

Glad to hear you got her going again.