I have a DL-50 that is about two years old and it has very little compression. It may have always been this way just not sure? I can turn the prop by hand with little effort when it's cold and nearly freewheels when hot is this normal? It starts on about the eighth flip or so and has plenty of power. I never tried to start it while it's still hot but I can't see how it can. Is this normal for a gas engine or do you think something is wrong? I have it on a Cap232 27% and 23A vess prop. I used Lawnboy 32:1 during break-in and now use amsoil 100:1.

Sounds as though the ring is history

With those choices of oil and mix ratios I'd be surprised if all it needed was a ring.

....would be interesting to see high res pics with the cylinder pulled.  </p>

If it feels the same after you put several drops of medium viscosity oil into the chamber and reinstall the plug, it may be something else than the ring.
Did you verify the head bolts?

Stuck ring. Everything needed to complete the process was executed perfectly.

Sorry man, thats the 2 worst oils you could have used.

Lawnboy is sludgey and leaves all kinds of gooey deposits on the ring grooves during the break in process. Would have probably been okay if you'd switched to a good synthetic and mixed it at 50:1 or 40:1. The synthetic would have possibly washed some of that sludge out of the engine.

Instead, you picked one of the worst oils a guy could have picked and mixed at 100:1. The Amsoil mixed at that ratio leaves no room for error. There's no extra oil there to help break down and wash sludge out of the engine. 100:1 is not enough oil to lubricate the engine properly and definitely not enough to help remove the Lawnboy sludge.

I'm going to look into my crystal ball and make the following prediction:
The ring is stuck
There's hard carbon sludge in the ring grooves
The piston skirt has excessive scuffing
The cylinder plating is worn through
The top of the piston has hard carbon on top

Basically, it's hosed....... big time hosed.

Have it rebuilt. This time, use a better quality oil, like Penzoil Air Cooled and mix it at 50:1. Really ANY high quality oil mixed at a reasonable ratio. My crystal ball says you'll wreck that engine before it needs another rebuild.

100:1 is the equivalent of a shot glass of oil in your 1 gallon gas can. Thats not enough oil. An engine needs more oil than that. Oil not only provides lubrication, it helps increase compression and seal, delivering more power. It also carries heat out of the cylinder and to the exhaust system.

Sorry to be doom and gloom. Thats my honest opinion. Good luck with the engine.

My conclusion.

The engine started out with no compression, (square piston in round hole or vise/versa).  A couple years of blowby and the ring is toast.
Folks should return an engine that doesn't have good compression. Or doesn't achieve it within the first couple tanks.  Nothing good will come from you having to do the coarse grinding and fine honing the MFG'rs skipped.

Rcpilot,

I'm thinking that if the piston hasn't been too badly abused and the cylinder plating is relatively intact he's got a good chance of saving what's left and obtaining another season or two with the engine. He'll have to tear it down and expend a little time and effort in the reconditioning process. If the ring maintains it's tension after cleaning the ring groove, the top and back of the ring, and the combustion areas of the piston and cylinder, he just might pull it off.

Worst case is he orders a new top assembly and starts over with another break in using a good oil at a reasonable ratio. That would save the cost of round trip shipping if he did it himself. Costs in the area of $200.00-$250.00 and working time of about an hour or so. If cleaning did not work I'd give Jody at Valley View RC a call for the parts.

The hard carbon deposits are almost a forgone determination.

TOM- Now *THAT* is absolutely the most succinct and on-target statement that could have been made.

RcPilot - Ditto.

Owner - please just get it rebuilt, and this time use a different break in, and try not to find out how LITTLEoil will work....that really is something that no one wants to really know. Sorry this happened to you....

T.O.M

It's possible the piston skirt survived and the cylinder still has chrome. In that case he could do as you suggested and simply clean it. If the ring is still springy and the cylinder has chrome it might work.

But if it's been heated too hot the ring could be brittle and crumble when he attempts to remove it from the piston. It's possible the cylinder is completely worn down to noting and there is little or no chrome plating left.

You could be right. We'll probably never know. I doubt we'll see any detailed pics of the engine in question.

If he can do it himself the whole top end, including piston, ring, cylinder, wrist pin and brg., and gaskets would costhim about $125 including shipping. If I do it, you can add$40 plus about another$30 in shipping.

My concern with thelong term running of suchlittle oil is thebig end of the rod, if it needs a new crank also, forget it and buy a new DLE55. If theCylinderand piston can be reused it might be worthputting a new crank in it but it would probably be marginal.

 

 I have been reading &amp; following along this thread &amp; have a question or two. Is it possible for him to get the probable stuck ring unstuck with some type of chemical soaking? I am wondering how the motor is developeing power if the ring is not seating against the cylinder wall? Or is it just down on power &amp; he doesnt realize it? Thanks.....Gene

"It starts on about the eighth flip or so and has plenty of power." Apparently it's performing within the owners expecations, why is a rebuild necessary?

Thanks Gentlemen for your help so far. I came home tonight and decided to pull the cylinder and see what was going on. Before I did I made sure my brain was not playing tricks on me. I put my finger on the prop and turned and turned and it had very little resistance. I also fliped it and it was a little hard to find the compression stroke. What I found was the cylinder had three shinny vertical lines about 3/8 " wide each but not scratched or scored. The piston ring was not stuck I was able to move it easily, not broken, and very little carbon. I will try to post some pics. before I go to bed tonight.

You will alsowant to check the ring end gap with a feeler gauge, remove the ring from thepiston and slip into the cylinder about 1" from the bottom and measure the gap at the ends,you'll probably find it near or over .020" which is way to much and indicates a very worn ring. A new ring in a cylinder within tolerance would have about.005" end gap. New cylinder and new ring, less than .002".

I hope my pictures show up?

I checked the ring end gap and it's a tight .002" I checked it in several places also.

The initiation of a hard carbon crust is evident. The ring groove has started carbon development and a later stuck ring is likely unless it's cleaned up. The carbon trace below the ring on the exhaust side of the piston is caused by a ring not generating the tension it should have, permitting exhaust gas blow by. A condition assisted by too little oil btw. The exhaust port is well on it's way to becoming coked up. It will become worse, eventually blocking a large portion of the port. I have seen this many, many times.

If you would like to save some money and do very little to keep flying the engine, run on down to a local motorcycle or saw and mower shop and pick up some Pennzoil Air Cooled. Echo or Stihl two stroke are another pair of good oils for what you need to accomplish. Mix and run at 32-1 for about 5 gallons or so to let the engine self clean. If you can't find the Pennzoil, Echo, or Stihl, head to Wal Mart and pick up some of their house brand air cooled two stroke oil. Same ratio, 32-1. Both will work and work well. The Pennzoil is better but where you're at it doesn't matter. Both will clean the engine. 32-1 will perpetuate a better ring seal. When you re-assemble coat everything...everything, with the new oil before it goes back together. Straight oil! You'll probably foul the plug after the first start but you want that oil in there. It will take close to an hour for the engine to have completely drawn fresh oil throughout itself in normal running without the pre lube.

A pic below of a port in an engine running too little oil. My thanks to RCU for giving the edit ability back. Without it you would not have the picture.

I gotta say:
EXCELLENT follow up!! It's very frustrating to try and help in a situation like this when the original poster offers no pictures for evaluation. I am REALLY happy to see this thread stay on track and see ChristanEagle follow up with pictures and details of how the ring feels. Great job guys, and I stand corrected. We DID see pictures. [sm=thumbs_up.gif]

I don't see excessive piston skirt scuffing and the cylinder looks okay for the most part. I'd probably clean the exhaust port now and then reassemble and run as T.O.M. instructed. It will self clean with a quality oil and a richer mix ratio.

christane can you take a better picture of the inside of the cylinder. If this engine never had compression and still doesn't I bet the cylinder is either damaged, or more than likely from what you have said was not bored and plated correctly. Just what altavillan said. Square peg in a round hole.

That's a more common issue than many know.

Question: How did you check the ring end gap? That's a smidge important. I'm presuming you removed it from the piston, inserted it into the cylinder in the correct orientation, and assured it was square with the combustion dome?

Exactly, if you don't put the ring in the cylinder in the same orientation as it has been run you will not get a correct reading. I really find it hard to believe that it has .002" end gap if it has been run for two years on 100:1 of any kind of oil.

I two would like to see the cylinder better, you can't see the condition of the wall at all in the pictures. This has already been mentioned but your description of "three shiny verticle lines about 3/8" wide" could indicate a cylinder that is not exactly round, if so, and this engine had low compresion when new and did not improveafter a couple tanks of fuel, it should have been returned at that time.

I have to say you guys have turned me around about RC universe. Once I did a post and some wise guy degraded, flamed me and I said who needs this and have not used this forum until now. Back to bussiness. I put the ring into the cylinder and used the piston to push it into the cylinder then I measured to make sure it was even. My thoughts now are should I buy a new piston,ring,cylinder or just put it back together and start the break-in all over again. I also should tell you this is my first gas engine and now have two. I had this mind set because a lot of people I know say lawnboy and amsoil are the best of the best. I personally have used lawnboy oil in a weedeater (ECHO) for 25 years,yes the same weedeater and it runs great today. 32:1. I am open to using a diffrent oil at this forums suggestions. After going back and reviewing the manual I don't know where I got 100:1 unless it was looking at the DA web site. I am starting to believe the gentleman that said it must of had no compression from the start and this was my first gasser I simply didn't pick up on it. I made some rookie mistakes here but I want to do whats right because I still believe in the DL engine. Your help is much appreciated and I will try to take some pictures that show the cylinder in a better light.

What do you mean "I checked ring gap in several places? That does not sound right. Ring gap is measured at the ring ends!!!!!!!! Capt,n Put a new Frank bowman ring in it and run it...simple.