AC kills Generator

[mikell]

Onan 4k but I think it's really like 3500. Dometic 13500 AC i turn it on to fan and let the generator balance out then switch to AC and it pulls it right down till it stalls. I'm going to put a watt meter on the line tonight. I don't have good 120 line power where it's plugged in right now so I haven't really tried that other than when it was cold outside it seemed to kick in fine.

The genny has about 60 hours on it and I have been running it nearly every day to get the fuel flushed out so I have put probably 20 hours on it in the last month.

[hankpage]

I know it's been discussed before, so you may want to do a forum search for "Hard start capacitor". Many folks find adding this option to their A/C helps it start and not pull down the gen. Maybe someone who installed one will chime in and explain further.

[f6bits]

I'd be interested in seeing what the watt meter says when the AC is off. A 3500 should easily run the 13.5, but not if a bunch of other stuff is already drawing power.

[rnkburg]

I also remember something on here where one set of breakers was bad or wired wrong on the generator. So it was only getting half power.

But if the engine is dying under load then you may have a high speed carb jet clogged. It doesn't take much for fuel to go bad. The latest study show between 15 and 30 days for the new fuel to go bad. This won't effect your car but small engines its horrible. Also do not run e85 its murder on the small engine. You may try a product called lmt to clean the carb, or mechanic in a bottle but those are hail Mary's as I call them hoping it will work. Probably going to have to clean carb and jets and or replace.

One cleaned run stabil all the time. Use the marine version as it has twice the strength plus works for ethanol and high moisture situations.

Hope the helps and good luck.


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[mikell]

The genny is in my class C so I can't just add carb cleaner. It runs the normal loads fine and nothing was on during yesterdays test. I'll put an amp meter on tonight maybe but headed to the dentist for a crown prep so might not feel like doing much later.It starts good but takes a bit to balance out maybe a minute or two so maybe a governor issue along with the jet???

[rnkburg]

You can spray lmt into intake of gen while running it will white smoke like crazy. You can also soak it full while not running and then start throw a load to it and see if it helps. I have seen high speed jets do exactly as you describe.

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[mikell]

Might give that a try when / if the rain ever stops

[BigCajun]

Sounds like it is starving for fuel under a load. Check your lines for kinks, change the fuel filter and add Sea Foam to the fuel. After running for about thirty minutes without load, try to load it. It may take a few times (Ive had to do this already). If that doesn't work, try changing the fuel pump.

[mikell]

Rain all week it looks like but I found another meter I'm picking up to keep an eye on things when I get a chance to work on it.

http://www.ebay.com/itm/251244750308?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_4025wt_966

[WYO 85]

Make sure your refridge is on gas only!

[randy69]

If everthing else fails after looking at the electrical and carb. This is what I have found with mine. The gas tank does not vent right so my gas line colapsed a little, Doesn't let enough fuel to the carb when the demand was there. So I cracked the unvented gas cap I could here a lot of suction.

[mikell]

It's on my class C that we use for short trips. 55 gallons of gas but I'm not sure about the fuel pump. I don't hear it running and it turns over alot before starting. Might pull the unit this weekend and go thru everything.

Got some carb cleaner to try tonight

[f6bits]

Does your generator have an Overload light? My little Yamaha does, and if I turn the AC, the generator cranks up to overdrive, then shuts off with the Overload light turned on.

[mikell]

I let it warm up then turned the AC fan on for a minute then on AC and it pulls it right down but if I shut the AC off the genny stays running. Going to run some carb cleaner thru it tonight if it's not raining.

Ordered a amp and watt meter to install just before the breaker panel and putting 12 volt amp and watt meters tied to the coach battery

[BigCajun]

It's on my class C that we use for short trips. 55 gallons of gas but I'm not sure about the fuel pump. I don't hear it running and it turns over alot before starting. Might pull the unit this weekend and go thru everything.

Got some carb cleaner to try tonight

Fuel pump is on the onan. If it takes a while to prime (if you press STOP once, then again and hold, it should prime the genny), then you probably have a fuel filter or pump problem. Not hard to change with unit on the table. Not sure how hard it is mounted in coach.