Decelomatic Correction
In the August 2006 “Tech Talk” column, it was reported that Mr. Louis King of Decelomatic Corporation had passed away and his company was no longer in business. Even though we had received this information from several different sources, we have since discovered that it was incorrect. As in the case of Mark Twain, the rumors of his death and his company’s demise were grossly exaggerated. Mr. King and Decelomatic Corp. are still alive and well in Phoenix, Arizona, and can be reached by calling (602) 955-8514. We apologize to Mr. King and regret this error.
Wrangling A 2007 Wrangler
Q:
I tow a 2006 Jeep Wrangler Unlimited, but I’m thinking ahead. Will the 2007 Wrangler be towable, and what would be the best wheel size to use on it: 16-inch or 19-inch?Bo Lee, F166936
FMCA Mail Forwarding
A: By all accounts, the 2007 Wrangler looks to be possibly the most popular Jeep yet. At this writing, we had not sent out our 2007 towing survey to the vehicle manufacturers yet (the results of which will appear in FMC’s January 2007 issue); however, I did visit www.jeep.com and called (800) 925-JEEP “” the information number I found there “” and was told that depending on the transfer case used, the 2007 four-wheel-drive Wrangler may be flat-towable with all engine and transmission choices. I’d suggest you wait until the vehicle’s owners manual is finalized before ordering one.
As for the wheel size, if you’re planning on using it off-road and lowering the tire pressure for improved traction and ride, the 16-inch wheel and tire is the better choice. Sixteen-inch tires have higher sidewalls; therefore, the rims are not put at risk as much as they would with 19-inch wheels. If you’re just going to tow the vehicle behind your motorhome and use it around town, the 19-inch wheels are showier. Plus, I checked the major tire manufacturers’ Web sites and found that there are far more choices for off-road tires in the 16-inch size. In fact, I didn’t see any 19-inch off-road tires at the time of this writing.
Generator Problem
Q: I own a 2004 Winnebago motorhome with an Onan generator (model KY-FA/26100 B), and it recently developed a problem I can’t seem to fix.
I was camping in the Sacramento Valley, and the air temperatures reached a high of 105 degrees (I’ve camped in similar temperatures in Arizona this past year with no issue). The generator was running normally when it began to surge. It began varying rpm just a little, but within about a minute, the surge was so dramatic that it died. I tried running the unit in late evening as well as in the morning to see whether the air temperature was an issue. The problem was the same; it seems like a gas supply issue.
In order to restart it, I had to let it cool off and then use the “prime function.” The gen set would then restart and run normally for about one to two minutes, then the surging started again and the engine died. Each time I needed to let it cool before I could hear the “prime” clicking sequence. This continued for four days.
The error code I received was “36” (a fuel supply problem?). The motorhome has a full tank. I disconnected the fuel line as it enters the generator case, checking for fuel flow. The fuel flows freely, suggesting that there is not a fuel supply problem to that point.
The unit currently has 115 hours on it. I changed the air filter (using an Onan filter) and the oil in May. I had no problems prior to this date (the reading at that time was 113 hours). Following the service, I was camping on the coast and used the generator for almost two hours with no problems.
Here is a little more information on the gen set’s behavior. When the engine is cold “”hasn’t run for about two hours “” I need to prime it, and then start it. The engine will run very smoothly (normal) for about three to five minutes. Then the throttle starts surging, first a little, then a lot. Within one minute of the throttle beginning to surge, the engine will die. If I attempt to restart the engine, it will not. If I attempt to prime it, there is no sound of the electronic prime function working. Normally I can hear a clicking sound.
My analysis is that as soon as the engine warms up, the problem presents itself. And as long as the engine is warm, it will not restart. If I wait a half-hour or so, it will restart, but it then dies within one to two minutes. Again it’s a reflection of the engine being pre-warmed.
Today I shot some carburetor cleaner into the air cleaner cavity, replaced the air cleaner, and started the cold engine. (It hadn’t run for a day.) The engine ran smoothly for five minutes, then began to surge and died within one minute. The instructions on the side cover of the gen set insist that the side cover be in place while the engine is running. This I have done on all occasions. I did verify that the fan inside the unit was turning, so the cooling system seems to be functioning.
What do you suggest I check next to correct this problem?
Shelton Campbell, F319411
Auburn, California
A: It appears that you’ve pretty much diagnosed your generator’s problem without any help from me. However, you did not take the lack of fuel issue far enough. The same thing happened to my generator last summer, even after I’d used it on several trips without any problems. The motorhome’s previous owner had failed to keep clean, fresh fuel in the carburetor’s float bowl and jets, and a buildup of varnish within those items occurred. Even though I’d used the generator several times, the layers of varnish eventually became too thick for fuel to pass, and it began surging and then dying. I had to replace the carburetor.
By the way, the reason it will run while cold is because, as you know, a gasoline engine needs a much richer fuel-air mixture when cold to operate properly. Once it’s warm, the engine floods out. I’m afraid you may have to replace the carburetor with a new one. Hereafter, to keep the carburetor clear, you should operate the generator under load “” running the air conditioner will suffice “” for at least 30 minutes each month. Plus, add a fuel preservative and stabilizer to your fuel system each time you store your coach for six weeks or more. Mix the stabilizer in with the final fuel fill-up just prior to storage, and remember to always store your coach with a full fuel tank to prevent condensation from collecting in the fuel tank.