Your piston to cylinder clearance is perfect, that's a .00175" clearance. Alignment is most likely the problem.

Originally Posted by Jedijody

Your piston to cylinder clearance is perfect, that's a .00175" clearance. Alignment is most likely the problem.

O-No-SPS shiney piston spots.Pulled the cyl on the Syssa and it had SPS worst then any of my DLs.Plus some burrs on the ports that made little gouges on the piston,cleaned up real nice. Will fly it some more tomorrow. SPS is Ralph,s idea.
BCCHI

about the idle stop screw... i take a dremel and cut off disc and remove entire bracket from cover. saves a lot of weight!

Before everyone jumps on me... In th elast 2 night s I have read up to page 354. I am looking to see what size ignition battery people are using. Is there anyone that could help me out with the size, is 1500mah enough? From what I read 4.8 is desired. Thanks for any information.

4 cell Nimh or Nicad, 800 mah is plenty for an hour of engine run time, 1500 mah will give you 2 hours or 12, 10 minute flights.

Originally Posted by Jedijody

4 cell Nimh or Nicad, 800 mah is plenty for an hour of engine run time, 1500 mah will give you 2 hours or 12, 10 minute flights.

Thanks Jody

Originally Posted by Jedijody

Your piston to cylinder clearance is perfect, that's a .00175" clearance. Alignment is most likely the problem.

Is there somewhere I could read up on how to get the alignment right?

Originally Posted by hot4teach

Is there somewhere I could read up on how to get the alignment right?

There is an easy fix for their lack of perfect alignment (Jug to case) using alignment dowls or pins (jug to crankcase) would be a great update to any of the gas engines we use, and not that hard to implement. pins or dowls in the jug and alignment holes for the pins,dowls in the crankcase or just the oppisite, it's known as R&D. Sure would take all the guess work out of it .

You don't want perfect alignment between jug and case. You want perfect alignment between clylinder bore and piston travel, quite different.

I've written how to do it in this thread, don't have time this morning to do it again. Try the search or maybe someone else could point you to it.

Originally Posted by hot4teach

Is there somewhere I could read up on how to get the alignment right?

https://www.flyinggiants.com/forums/...nt#post1634406

first post on page.

Jody explains how to align the cylinder to the crankcase.

Thanks for the reply Jodi!!!

Just my 2 cents worth. I like every one else was plagued with new engine problems, from multible dead sticks;, from me trying to lean out the "burble" ,to weak ignitions. This engine is not a DA nor is it that expensive! I n my experience most of the trouble has gone away with usuage; Ihave got now 4+ gallons through it and it continues to get better. Iam not saying tha that they are all that bad but for some of us that got an engine that was not quite right ;as that ring continues to seat and has less blowby, compression at lower RPM'S improves so base compression improves; atomization of the fuel is better, pulse to the carb is higher. All in all the engine is more relliable. To me while you can pretty much tune a DA on the ground not so with my DLE . Fly it and make small adjustments and be patient. I found that creeping up to get rid of the burble a little at a time, the time that just a lean on the low speed needle produced an engine that sagged with acceleration and rolled inverted dead sticked. This engine I have seems to have to be tuned to the point that it runs properly inverted and how it runs right side up is that result. Imight add that at the field the DLE is not alone at that. Most of the DA's 50,60 etc. single cylinder engines flying along at maybe half throttle with a noticeable burble ,when rolled inverted will clean right out. This must have some thing to do with carb placement in relation to crank centerline,or cylinder up vs. down because opposed cylinders don't suffer from this. My experience again with this engine is do not try to eliminate the burble. I fly 3 D and in present tune it is just right. Looking at your piston as much as one can see ; I maintain and work on 2 and 4 cycle race engines for a living. misalignment is caused by a centerline difference between the 2 ends of the rod in building the rod is put in a holding device and in simple terms twisted to align the top to bottom centerlines. Perhaps the scoring is just from leaning the engine tooo far. Usually this is the case. Just a parting thought about the misalignment usually it causes a diagonal wear pattern on the piston skirt .

Originally Posted by ronc

Just my 2 cents worth. I like every one else was plagued with new engine problems, from multible dead sticks;, from me trying to lean out the "burble" ,to weak ignitions. This engine is not a DA nor is it that expensive! I n my experience most of the trouble has gone away with usuage; Ihave got now 4+ gallons through it and it continues to get better. Iam not saying tha that they are all that bad but for some of us that got an engine that was not quite right ;as that ring continues to seat and has less blowby, compression at lower RPM'S improves so base compression improves; atomization of the fuel is better, pulse to the carb is higher. All in all the engine is more relliable. To me while you can pretty much tune a DA on the ground not so with my DLE . Fly it and make small adjustments and be patient. I found that creeping up to get rid of the burble a little at a time, the time that just a lean on the low speed needle produced an engine that sagged with acceleration and rolled inverted dead sticked. This engine I have seems to have to be tuned to the point that it runs properly inverted and how it runs right side up is that result. Imight add that at the field the DLE is not alone at that. Most of the DA's 50,60 etc. single cylinder engines flying along at maybe half throttle with a noticeable burble ,when rolled inverted will clean right out. This must have some thing to do with carb placement in relation to crank centerline,or cylinder up vs. down because opposed cylinders don't suffer from this. My experience again with this engine is do not try to eliminate the burble. I fly 3 D and in present tune it is just right. Looking at your piston as much as one can see ; I maintain and work on 2 and 4 cycle race engines for a living. misalignment is caused by a centerline difference between the 2 ends of the rod in building the rod is put in a holding device and in simple terms twisted to align the top to bottom centerlines. Perhaps the scoring is just from leaning the engine tooo far. Usually this is the case. Just a parting thought about the misalignment usually it causes a diagonal wear pattern on the piston skirt .

I would agree with some of what you say. Yes if the rod was twisted as you say it would show up as a diagonal wear on the piston. But if you look at the pics it is clearly a misalignment of the bore to the centerline of the piston/ rod assembly. If you have ever taken a dle apart you would notice the Jug does have some play where it sits in the crankcase. It allows the cylinder to to be assembled with the bore being misaligned if not done correctly. The wear on the piston above shows clearly that is the case. If you read the post that I referenced above it explains it clearly how it needs to be done and why. That said, I do seem to think in my opinion that the dle 30's are a tad more sensitive to adjustments and getting better and more reliable with run time then say the 55's. We have a 30 that was converted with a bowman ring and to a rear carb. That engine came to life quicker and easier then the one left stock out of the box with the stock ring pictured above. It idles better and just runs perfect. As far as running it lean? I don't think so. Nowhere on that piston shows a lean run. All it shows is the blow by where the ring has not seated yet.

O boy I wish I would of known about this when I put a Frank Bowman ring in my new DLE 30.
I was just so use to Zenoahs and the like that it never occured to me.
I think I may have done this but really don't remember.
I guess I'll pull her apart and look at it.
I don't really think I have more than 2 gallons of fuel thru it but I need to look it over just in case.

As Steve400 qouted.

"We have a 30 that was converted with a bowman ring and to a rear carb. That engine came to life quicker and easier then the one left stock out of the box with the stock ring pictured above. It idles better and just runs perfect"

I can vouch for that!!!

Even the Dle55 with the Frank Bowman runs perfect with a 23B Vess.

Originally Posted by steve400

I would agree with some of what you say. Yes if the rod was twisted as you say it would show up as a diagonal wear on the piston. But if you look at the pics it is clearly a misalignment of the bore to the centerline of the piston/ rod assembly. If you have ever taken a dle apart you would notice the Jug does have some play where it sits in the crankcase. It allows the cylinder to to be assembled with the bore being misaligned if not done correctly. The wear on the piston above shows clearly that is the case. If you read the post that I referenced above it explains it clearly how it needs to be done and why. That said, I do seem to think in my opinion that the dle 30's are a tad more sensitive to adjustments and getting better and more reliable with run time then say the 55's. We have a 30 that was converted with a bowman ring and to a rear carb. That engine came to life quicker and easier then the one left stock out of the box with the stock ring pictured above. It idles better and just runs perfect. As far as running it lean? I don't think so. Nowhere on that piston shows a lean run. All it shows is the blow by where the ring has not seated yet.

In answer to your observations,blowby from a ring that has not totally seated usually will leave a brown burn on the piston skirt below the ring. Hard to say looking at the picture if the mark in question is scoring or siezure. I have not looked at the barrel of the DLE and the allowed movement ,BUT there is enough side play in both ends of the rod to accomidate this dimension. If that piston was being "pushed" against the bore, the crank or the wrist pin bosses in the piston would also show evidence.