4.0 CCK starts/runs fine. Hunts & shuts down after 10-15 minutes

[LJ-TJ]

I have a 4.0 CCK. Runs like a dream sort of. It fires up nice runs nice for about 10/15 minutes and then starts to hunt and shortly after words shuts down. Wait a bit and she fires right up and again after a few minutes shuts down again. Any thoughts. Doesn't appear to be any gas leeks any where.

[DaveVA78Chieftain]

Are you able to see if it still has spark right after it shuts down?  Thinking coil getting hot and opening up.
Dave

[LJ-TJ]

You know that old saying you can't see the forest for the tree. Never thought to look. I was so busy looking at everything else. I'll check it tomorrow. Thanks Dave.

[Rickf1985]

Mine did that and I found out the points were burnt. Cleaned them and it ran fine. Mine started to hunt much sooner though.

[Stripe]

Weird, my Kohler did the same thing until I started making sure there was enough gas in my fuel tank...  It would run then died after a minute or so..  Restart it then same deal..  Filled tank with about 20-25 gallons of fuel and it ran fine..

[cosmic]

yup my money is on the coil. Let us no...

[LJ-TJ]

Ok, here's the head scratcher I took the cover off the points box and it was wet in side so I blew it out with compressed air and dried it out. Fired up right off. So I sat there and watched it run and very slowly gas or oil started to come up around the little rod that opened and closed the points. I sounded like it was starting to boil or hissss. Also when I blew compressed air around cab it blew or sucked gas out of the carb bowl. I tightened the two screws on the carb but when I went to blow it again the same thing happened. Do you think I need a new gasket on the carb bowl or do you think the carb is warped?

[DaveVA78Chieftain]

Sounds like it or the head may be warped. You will have to take it off and use a straight edge to check both.

Not many CCK parts around.  You may have to get a machinist to redo the bushing and/or plunger for the points.

Dave

[LJ-TJ]

Thanks Dave. Yeah as usual I'm finding out the hard way. Parts for the CCK are like trying to count hens teeth. May have to sell them and up grade to something a little newer. Geeeeeeessssss D:oH!

[LJ-TJ]

OK so new situation. Cleaned up the points and took the top of the carb and made a new gasket. Learned a new trick for punching holes in gasket material if you don't have a punch set and that is find a nut and bolt the same size as the hole needed and set the gasket material over the nut and tap the bolt, punches the hole out perfectly. I know you old timers all ready new that. Any way now she starts right up. Hunts a little until she warms up and then smooths out. Now the problem is when I put her under load ( Micro Wave) she starts to hunt again. How ever I noticed that even though shes running there appears to be know gas in the fuel filter. Seems just enough gas to keep the generator running but the filter looks empty. Hm?

[moonlitcoyote]

We use sockets to punch holes in gasket material.

[legomybago]

ritchen the fuel mixture screw some..

[LJ-TJ]

 D:oH! How do you do that? Or what does it look like. Its a 4.0 CCK  Hm? i?? I know it's not funny but at this point I gotta Laugh. Thanks for your help.

[legomybago]

I just looked online at what a 4.0 cck carb looks like, and I've never worked on one??....Not sure how you adjust them. Someone here does though W%

[LJ-TJ]

Thanks for trying.

[DaveVA78Chieftain]

TJ
Apparently there a 3 different models of carbs used on the CCK.  Please post a picture of yours for reference.   The engine manual is the 927-0754 (covers spec A through J) one in the Free manuals area.  All of them have idle and Main fuel adjustments on them.

Dave 

[LJ-TJ]

Hey Dave, She's a Marvel Schebler 138-Y73

[DaveVA78Chieftain]

Down draft style Carburetor

Onan has an odd way of referring to it.  It's the Gasoline Carbuetor not the the Gas-Gasoline Carburetor in 927-0754.  Page 21 (pdf 23).  Adjustments and overhaul information are in that manual.

Parts books: 927-0310 and 927-1037.

Carburetor Overhaul kit is 142-0371 however you are not going to like the price of it.

This might work for the breaker box:  http://powerparts.ecrater.com/p/17102698/onan-160-1097-breaker-box-0913-0980-cck

Dave

[kattkisson]

This is another given.  If yours feeds off your gas tank for the camper it has a drop tube that is shorter tan the camper drop tube in the tank.  This is for obvious reasons to allow you fuel to get away from the camp site. Do you have at least a 1/4 tank in the camper?

[LJ-TJ]

Thanks Dave. >GRIN< Now what do I do with them.

Yeah Kat the tank is 3/4 full.
I was messing with it for a bit this morning and noticed that while yesterday there was no to very little gas in the fuel filter this morning the was a  little more fuel visible. She now seems to start good with a little stumbling and searching on the start but then smooths out. Seems to do the same thing when she goes under load.

[LJ-TJ]

Hey Dave do I have to back the nut off that the little Tee hand screws into before I try to adjust the Tee handle or can I just turn the Tee in or out with out loosening the nut.

[Rickf1985]

The big nut holds the fuel bowl on and the little nut is a packing nut that has a seal in it to keep gas from leaking out past the main jet adjustment. Leave them alone and just turn the screw.

[LJ-TJ]

Aaaa Ha that's what I was wondering about.

[DaveVA78Chieftain]

TJ,
Did you download the 927-0754 manual from the members area?  I provided you page numbers for this carburetor.
Parts kit:



http://www.ebay.com/itm/NEW-ORIGINAL-ONAN-142-0371-CARB-REPAIR-KIT/221488159248?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140602152332%26meid%3D8178920987810124047%26pid%3D100011%26prg%3D20140602152332%26rk%3D1%26rkt%3D10%26sd%3D141245683875

http://www.anyrvparts.com/ProductDetail.asp?PID=12611&SID=39&DID=59&CID=108&BID=


Cheaper overseas: http://www.thexmod.com/item_detail.asp?id=2212

The big nut holds the fuel bowl on and the little nut is a packing nut that has a seal in it to keep gas from leaking out past the main jet adjustment.

Not really for this carburetor. The bowl is held in place by 4 screws (see them on top in your pictures).

Please download the 927-0754 CCK Engine Service Manual. 
Dave

[Rickf1985]

I saw that after I posted but I figured he got the idea so I would not confuse things by adding to it.