camss69

My Feedback: (46)

Dave,

Unfortunately I seem to have got a bad gallon of fuel and I'm concerened I may have hurt my previously flawless YS120. Story goes, I bought a brand new gallon of fuel YS 20/20. Because of the way the events played out I didn't realize I had bad fuel at the time. I ran the engine up several times attempting to tune the high speed needle with poor results, I'm thinking the engine got hot while doing this because it was dropping RPM's no matter how rich I set the needle and leaning it diddn't help either. I couldn't get it to idle and tried several times, and tried several plugs as soon as I took the glow starter off it died. Here's where it gets scary I noticed much less oil on the wing than normal. I usually run the engine pretty rich so I have a lot of oil on the wing normally. Also what oil there was, was very dark in color. Tonight I finally realized that I had not tried a different gallon of fuel and when I did the engine appeared to idle fine, appears that was the problem. I have no idea if the bad gallon was missing oil or nitro, I'm hoping nitro obviously but it concerns me that there was so little oil on the wing and the dark color. So should I try and fly it and hope it's ok or is it better to just send it in it does appear to run ok now but I would like to avoid having a problem half a gallon from now. I probably tried to tune the high speed 4 times or so, and probably got the engine pretty hot all 4 times. I'm quite ticked that the fuel was bad out of the jug and i have to say my opinion on wildcat fuels is in the tank right now.

Dave Shadel

I'll bet you didn't run it enough to cause a problem. Try it with a gallon of fuel that is known to be good.

Sounds like the fuel was short on oil.

camss69

My Feedback: (46)

Dave,

Well today I finally got to try to actually fly the thing again.. It idles now, but seems to be changing RPM, hunting up and down just slightly, it also sounds like it has small backfires when throttled back. Idle doesn't seem as smooth or as low as it used to be and today I had to make two deadstick landings. I noticed low speed was speeding up slightly so I richened it 1/8th turn on the regulator, where as before (before the bad fuel) it was slightly rich cause it would slow down just a tad when I took the glow starter off. Also it seems to fly faster at lower throttle settings, I know it's not lean cause I have a nice smoke trail. I used to tune high end to approx 9600 RPM with an APC 16x6, I could get it over 10k if i leaned it out. Today I tuned the same and it also seemed to hunt slightly at WOT.

Please advise..

Dave Shadel

Have you changed the glow plug?

camss69

My Feedback: (46)

Yes, I had a new plug when I first went out there, and then tried another brand new plug.

Dave Shadel

Maybe the engine needs help. You have the service address.

2slow2matter

My Feedback: (1)

remember, you also said that you had the needle valves all over the place trying to get it to run on the bad fuel. make sure you have them adjusted back properly...I just had the same thing happen. I had some powermaster 30 percent that I usually run in my saito 56, but not in my 100. When I was running short on 15 percent at the field the other day, I decided to put the 30 percent into the 100 to run it one more time. I hadn't used the fuel in a few weeks. The engine would die as soon as I removed the plug. I thought maybe it was too rich (fuel cooling the plug between strokes). I leaned it up. Also, I was getting a lot of white smoke. I now believe that it was moisture in the fuel (from humidity) and that was the source of the white smoke (steam), and why the plug would cool off between strokes. I removed the fuel, and put the last of my 15 percent in, and it ran like a champ. I then put the other fuel in one of my two strokes and it ran like a champ too. Guess the plug staying hotter on the two stroke allowed it to burn the fuel just fine. I wouldn't make a habbit of it, and I used lots of after run oil after that, but it was a good way to get rid of the fuel without pouring it out. However, I wouldn't use yours, it may indeed be low in oil. If so, then the fuel complany may be liable for any damage to your engine....

Dave Shadel

Your only problem is PROVING that the fuel is bad.

camss69

My Feedback: (46)

Yes, I figure I'll come out on the short end of this deal. Runs on this gallon doesn't run on that one, same brand same label, pretty obvious it's a fuel problem. I just wish I had realized it sooner. I just had this engine rebuilt 6 months and $200 ago, it's just a shame it was running so well and I was so happy with it. I don't really expect the fuel manufacturer to do much, some guy calls him and says "hey your fuel ruined my engine" what's he gonna do, say "OK I'll buy you a new one right away!!" yeah right. Unfortunately I may be SOL, and they have lost a customer for life, like it matters to them... Hopefully Richard can save it.... again. I will be dropping it off at the shop this week, I pass right by there on my way to Bishop and Mammoth for work.

Dave Shadel

If you have both the fuels, I would suggest a quart of each be sent to Wildcat for analysis. If there is a problem, it would not surprise me if they take care of the fix for you.

Good Luck!

camss69

My Feedback: (46)

I figure I should update this in case anyone is following along...

I found the second bottle of fuel to be bad as well. I finally realized this when I was at the field with another guy and he was having the exact same problems as I was on my second gallon. I switched brands and today was finally rewarded with 4 great flights. This thing has been sitting for a month or so cause of these fuel problems I've been flying my other planes with the new brand with great results and it just never dawned on me my second gallon could have been bad as well.

Wildcat did replace the first bad gallon, and my plugs, I have not informed them of the second gallon, and don't know if I will. Probably just cut my losses.

The great news is the engine appears ok!!

Dave Shadel

Not a good advertisement for their fuel. First problem I have heard of with this brand. The guy who owns it has a good rep. You might want to let him know.

Glad the engine is OK. What fuel are you using now?

camss69

My Feedback: (46)

No not a good advertisement for them, but they did replace the fuel, and my glow plugs which was nice.

I've switched to powermaster, actually switched back I should say. I've always used their fuel before with great results. I think the only other fuel available in my area is Omega but I would have to go to a different HS to get that.

Dave Shadel

Thanks for the info.

Good Flying!