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Old 10-10-2013, 20:28   #1
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Kohler 7.5kw Genset problem

My 2004 Kohler 7.5kw genset has about 20 hours on it. It now runs for about 10 mins and then starts to misfire. When I open the engine room and watch it I see that the choke is being activated whenever there is a load on the genset. Any thoughts on how to fix this?
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Old 10-10-2013, 20:57   #2
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Re: Kohler 7.5kw Genset problem

Is this a diesel? what is the choke?
If diesel, she is sucking air into the fuel lines.
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Old 10-10-2013, 21:00   #3
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Re: Kohler 7.5kw Genset problem

diesels dont have a choke.

consult a carb person, they are before my time. i would say vacuum leak if i had to guess, but my knowledge of carbs is limited to how they operate.
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Old 11-10-2013, 05:57   #4
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Re: Kohler 7.5kw Genset problem

Quote:
Originally Posted by DiverseTrekky View Post
My 2004 Kohler 7.5kw genset has about 20 hours on it. It now runs for about 10 mins and then starts to misfire. When I open the engine room and watch it I see that the choke is being activated whenever there is a load on the genset. Any thoughts on how to fix this?
I think that's throttle auto advancing for the load not a choke.
Check your fuel lines as suggested, fuel quality and filter state, especially look for water or 'gunk' in the system.
If there's a small fuel filter or mesh insert on the engine you should check that too.
If that fails try running it from a can of known fresh fuel. Be careful of spills when you separate the fuel lines, use a clamped phillips screwdriver or similar to block the unused main hose while the engine sucks from the can.
All I can think of,
Cheers,
Mac
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Old 11-10-2013, 06:07   #5
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Re: Kohler 7.5kw Genset problem

Kohler made a lot of gasoline (petrol) powered gensets; I bet this is one of those.

I also agree with Mac that what the OP is seeing is likely the throttle, which the controller will open up to try to compensate when the engine starts to misfire, rather than the choke.

My bet is that with only 20 hours in 9 years, we've got a gummed up carburetor. I would start by taking the carb apart and soaking it in carb cleaner (use gloves, the stuff is extremely harmful!), clean it thoroughly, carefully clean out the jets, and try again. I bet that's the problem.
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Old 11-10-2013, 06:16   #6
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Re: Kohler 7.5kw Genset problem

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Kohler made a lot of gasoline (petrol) powered gensets; I bet this is one of those.

I also agree with Mac that what the OP is seeing is likely the throttle, which the controller will open up to try to compensate when the engine starts to misfire, rather than the choke.

My bet is that with only 20 hours in 9 years, we've got a gummed up carburetor. I would start by taking the carb apart and soaking it in carb cleaner (use gloves, the stuff is extremely harmful!), clean it thoroughly, carefully clean out the jets, and try again. I bet that's the problem.
Thanks for that Dockhead,
I must admit that by long before 2004 I thought all Kohlers were diesel only, maybe it's they're either not in this part of world or very rare.
I don't even have listing on a petrol option.
If we'd been betting I'd have lost big time.
Cheers,
Mac
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Old 11-10-2013, 06:24   #7
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Re: Kohler 7.5kw Genset problem

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Thanks for that Dockhead,
I must admit that by long before 2004 I thought all Kohlers were diesel only, maybe it's they're either not in this part of world or very rare.
I don't even have listing on a petrol option.
If we'd been betting I'd have lost big time.
Cheers,
Mac
Genset almost always burns the same fuel as the main engines. There are still millions of petrol powered boats around, so there's a big market.
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Old 11-10-2013, 06:24   #8
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Kohler makes a lot of gasoline generators, so do most other marine generator manufacturers. I concur that what is being seen is the throttle, not the choke. With so few hours since new I'd be willing to place a bet the carb is toast. Kohler usually used Honda engines on their gas sets. The carb is a replace it item.....just too small and cheap (relatively) to screw with.
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Old 11-10-2013, 06:43   #9
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Re: Kohler 7.5kw Genset problem

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Kohler makes a lot of gasoline generators, so do most other marine generator manufacturers. I concur that what is being seen is the throttle, not the choke. With so few hours since new I'd be willing to place a bet the carb is toast. Kohler usually used Honda engines on their gas sets. The carb is a replace it item.....just too small and cheap (relatively) to screw with.
Thread drift warning! Apologies to the OP.

I have a Honda suitcase generator -- an EU100i. It has the same problem -- few hours and many years of storage, and gummed up carb. Are you saying that it's easier to toss the carb and replace it, than try to clean it up, if nothing else is wrong with it? Surely not?
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Old 11-10-2013, 06:56   #10
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Re: Kohler 7.5kw Genset problem

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Genset almost always burns the same fuel as the main engines. There are still millions of petrol powered boats around, so there's a big market.
Of that bit above, I'm aware
Of this bit, I'm now painfully aware:
2004 Doral Elegante Power Boat For Sale - www.yachtworld.com
How embarasking, I shall now flagellate myself for not looking up the boat before posting, yer onner!!
Nice boat BTW,
Cheers,
Mac
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Old 11-10-2013, 06:57   #11
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Quote:
Originally Posted by Dockhead View Post

Thread drift warning! Apologies to the OP.

I have a Honda suitcase generator -- an EU100i. It has the same problem -- few hours and many years of storage, and gummed up carb. Are you saying that it's easier to toss the carb and replace it, than try to clean it up, if nothing else is wrong with it? Surely not?
You can jack around with this midget carb for days and still not clear out the microscopic passages.
What's your time and sanity worth? My brother in law has a gasoline storm generator, last used five years ago. Funny thing it wouldn't start. I spent two days on an off cleaning and soaking the carb, no joy. A new carb was less than $120 and took 10 mins to bolt on.
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Old 11-10-2013, 08:15   #12
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Re: Kohler 7.5kw Genset problem

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Originally Posted by scoobert View Post
diesels dont have a choke.

consult a carb person, they are before my time. i would say vacuum leak if i had to guess, but my knowledge of carbs is limited to how they operate.
Diesels don't have a carb either.

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Old 13-10-2013, 08:39   #13
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Re: Kohler 7.5kw Genset problem

Thanks for all the thoughts on this problem.

Yes it is petro/gasoline. Yes I do change the gas filter every other year. Yes it does have both a choke butterfly and a separate throttle advance to adjust to the load conditions. You can see both in the picture attached.

After reading through all the replies, I have decided to overhaul the genset this winter. Should have it ready for spring commissioning next April!

Cheers,

Daryl
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Old 13-10-2013, 08:44   #14
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Re: Kohler 7.5kw Genset problem

SO the picture didn't load the first time. We will try again!
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