Trojan Boat Forum

Does anyone know what the correct NGK spark plug would be for a kohler 5E 5kw generator? I bought the gen used and have around 80 hrs on it. It always ran good when I used it so I never changed the plugs that were in it. I ordered plugs about a year ago from a online generator supply sight. the new plugs were at least 1/2 inch longer than the ones that were in it. I just had a local marina look up the ngk plugs for me. the gave me BPR4ES. when I compared them to the ones that came with the gen (Champion CJ14) they are over 1/2 inch longer! The engine manual give a kohler specific plug.
I dont want to put in too long of a plug in and put a hole in the pistons .

Why not just cross reference the Champion CJ14?

Or stay with the champions . Look at the plug hole and the length . The thread of the plug should be about the same . Have you looked up the plugs in a champion catalog and see if you had the correct plug ?

I haven't found any info suggesting the champions are the correct plugs and have had no luck cross referencing them. I have a pretty good hunch that the previous owner used what he had laying around.
Having trouble getting the generator started after setting for 7 years. Not getting fuel so I believe it's the fuel pump or carb but want to make sure the plugs are correct as well.

Check your engine model number, there appears to be a difference, one ( bs04 )shows the plug that you were sent and the other (as04) is a short reach type something like your champion.....that is all I could find from old catalogue....Mike

Your genny takes a NGK BPR4HS, L92YC in Champion or R43CFS in AC Delco.

Just spent 3 hours researching these dam plugs! Couldnt find a definitive answer but Jamie bpr4hs came up as well as the bpr4es .
apparently there is know way to find out if you have a bs04 or and as04 gen??? guess I will try the longer plugs and await the sound of a smooth running generator or the sound of a piston slamming into the sparkplug???
just wish i knew why there were short plugs in it!

Thanks again Guys!

Todd did you look at the plug hole ? That will give you a idea of the plug thread length .. The plug threads should never go past the threads in the head .

Todd, I took that info from my Kohler manual. But, these generators used both Kawasaki and Honda engines so there may be a difference in the head design...

I have a small dental pick with a 90deg bend on the end. I'll carefully stick in in the plug hole and get a thickness on the head just to be sure.
Mine is a Kawasaki Jamie. Any idea what the difference is between the 4es vs the 4hs???

Okay, just got the info from my good friend and a Kohler dealer and tech. He said your genney uses the NGK BP5ES spark plug.

Jamie ,
I read someplace online to use that plug with the sound enclosure. I'll pick a set up and try they. I can always try the other ones as well if i t runs rough.
Thanks again!

Old "short" plug