Ram Jet

I doubt the exhaust valve will suffer as the high speed jet needle will feed her as much fuel as she needs so it shouldn't run lean. If the high speed jet were fixed that would be a matter of a larger main jet. I think.

Bill

w8ye

My Feedback: (16)

When you run with open exhaust you have to open up the needle some

Chancho

Upon teardown of the engine it's looking like I'll be in the market for a set of bearings too. All kinds of metal fragments in the case... I had scars in the sleeve and piston, too. The thing is I couldn't tell any noticable noise from the outside. It's been running great. The engine is under warranty, but with the broken jug and doing repairs myself it looks like I'll be spending almost 1/2 the price of a new one. Tough lessons...

Ram Jet

Correct! In the 60s I saw a-lot of guys who removed their muffler on their Honda 160 and 305cc motorcycles and attached, with a hose clamp, the chrome vacuum pipe extension from their mom's Hoover vacuum. Sounded really cool for a while - until they burned the face off their exhaust valves. Duh. Larger main jet please.

Bill

Ram Jet

Did you lose a circlip wrist pin retainer? All of the telltale signs.

Bill

w8ye

My Feedback: (16)

Get your bearings from http://rc-bearings.com/catalog/index.php They are a lot cheaper

Chancho

w8ye,

I've just been looking at the Saito 125 bearing failure thread. I'm looking at RC-Bearings right now. I'm not all the way thru the thread, but there seems to be a controversy over ceramic or steel. It doesn't seem like ceramic will hold up with the accidental bump of the engine on a light mishap. Than another member says just steel… I’ve been running %30 Cruelpower thru the 125 with a 13x11 APC 9,300 RPM. I work the engine hard %80 of the time. Will ceramic give me 8,000 more RPM or help me win the lotto? If the basic stainless steel bearings from rc-bearings.com are better than stock, for $7.95 it seems like a no-brainer. Or, help me understand if the Ceramic/Ceramic – Stainless are that much better.

My wrist retainer pin is in, by the way...

Thanks,

Phil

w8ye

My Feedback: (16)

I've some engines with ceramics but I mostly just get the regular bearings

Chancho

W8ye,

I almost opened a can of worms on the bearing choice. I think it was pretty well debated in the thread, "RE: Saito 125 engine bearing failure." Actually more research I like the idea of just plain steel, too. Anyhow, I’ll give RC-Bearings a call and see if he can convince me otherwise.

Phil

w8ye

My Feedback: (16)

You will be very happy with the regular bearings

Chancho

Gents,

Thanks for the help so far. I've been able to remove the bearings and have a set on order from RC-Bearings. I'm up in the air with the whole thing now because I'm not sure if the engine is too damaged.

Is this piston too warn? Is the case too damaged? It looks like the Rear bearing was spinning at one point inside the seat. The scratches on the side of the piston and in the jug, too. There are metal shavings in the case oil. There is pitting in the aluminum where the crank counterbalance turns, like it was grinding some debree into the aluminum at some point. I suspect the rear bearing, but I can’t visibly see any of the balls loose and the cage is intact. I don’t know where the metal shavings have come from. In regards to the piston retainer, this one has the white nylon-type retainers so there is no piston retainer pin to have fallen off. This engine has been running great until I put the plane in yesterday and broke the muffler off the jug. the engine stopped on inpact so this internal damage is something that has been going on for some time. Any tips on cleaning up the case? I’m thinking of a 600 grit except the obvious bearing seats? If I have to buy a case, piston, jug, etc.. It’s cheaper to buy a new engine. This engine only had about 25 hours on it…

Any input would be appreciated….

Frustrated,

Phil

w8ye

My Feedback: (16)

It certainly has had enough metal pieces run up through it.

It looks like the rear bearing spun in the case? what does the case look like?

I'd hate to run that piston in a new cylinder but it'll run if you put it together.

What is picture #4

w8ye

My Feedback: (16)

Looking at the #4 picture, it appears to be the rear bearing seat in the case. It doesn't look too bad

Be sure and clean this engine as well as you can to try to clean out all those metal filings

Chancho

Picture #4 is the case looking down from the jug hole at an angle. Starting from the bottom of the picture, the first transition area is where the inside of the crank counter balance spins. The second transition area is where the bearing seats and the third dirty area is where teh crank comes thru...

w8ye

My Feedback: (16)

I finally figured that out. The bearing seat looks OK.

The piston looks awful. Make sure there is not any steel still hung in those little scratches and that the ring lands are not chipped anywhere

w8ye

My Feedback: (16)

A piston is $31.50 plus shipping

Your old one is badly scratched but I think there is enough good left to run OK

Chancho

W8ye,

This is really the first 4 stroke I've totally taken apart. So I don't know how all this stuff is supposed to look but I’ve never seen something look this bad and run so good prior. For the $35 for the new piston I might as well since I'm getting the new jug. I’ll see how the case cleans up but I may add on the $50.39 for the new case. I just have no idea how a miniature Japanese Godzilla pooped metal all up inside my engine.

By the way, I read your posts and others on how to get the hub off and bearings out. I bought the puller today in a box of 3 pullers from Harbor Freight Tools down the street for $16. There’s lots of information out here and this is as good as it gets to online tech support. “Pretty darn good…” I can’t tell you and others enough, “thank you for the help!”

Best Regards,

Phil

w8ye

My Feedback: (16)

Phil if there is any problem, just get back on here.

There are a lot of us on here that enjoy answering questions

If I'm not here there will be a half dozen others that will fix you up.

w8ye

My Feedback: (16)

There is one thing you can do for me.

It was said by someone that Saito made the fins larger on the newer 125. When you get your new cylinder, can you compare it with your old one and give us a report if you think the fins are bigger on the new cylinder?

Chancho

You got it W8ye!

It's on order and I'll post a full report out as soon as it arrives...

[8D]

Ram Jet

If it were my engine I would proceed exactly as you are. 600 grit on what? The gasket mating surfaces? Only if there is obvious damage. If you want to "true up" gasket mating surfaces with 600 grit wet/dry paper tape the paper to a sheet of glass, make one or two smooth passes with a light oil on the paper, turn the part 90 degrees and repeat - then get off it when you have achieved a smooth surface of consistant color and tone. If you are going to go at the piston I would use 1200 grit and only if you have to to obtain a smooth fit between the piston and cylinder wall. If the piston fits well now I would leave it alone and let any high spots on the piston wear themselves away. If the cylinder is scored replace it and the piston unless you have acess to oversize pistons and cylinder hones. What I think you are referring to as Nylon wrist pin retainers may actually be Teflon wrist pin retainers and they are the best of the best for retaining a wrist pin.

I bought a used Enya .19 that upon receipt had the iron piston rusted tight to the steel cylinder sleve and the sleeve rusted into the aluminum case. A gentle application of propane gas heat, oil and a-little persuasion with a hardwood dowel and light hammering broke everything free. I VERY lightly honed the cylinder with my electric drill motor with 600 grit spinning on the end of a slotted wooden dowel. I did not want bare shiney metal, just a smooth bore. I cleaned up the piston and the outside of the cylinder liner with a very fine wire brush in my Dremel rotary tool. It has better compression than another .19 I have that has suffered no abuse.

I bought a used crankshaft for my motorcycle that came from a bike that he was "partsing out' because he suspected it had a bad crankshaft. Having sold much of the bike he then started to disassemble the engine and found that the local Honda dealer had dropped a small machine screw into the combustion chamber and that is what was causing the ominous rattle. Possibly some thing was left behind in your combustion chamber during manufature or possibly they installed a main bearing that shouldn't have gotten through quality control. Put her back together with new bearings. Think CLEAN, CLEAN, CLEAN. Make sure your piston ring doesn't appear abused. Pre-lube everything as you reassemble her. I'll bet she'll run just fine. Please keep us posted.

Bill

Ram Jet

It looks like the source of your damage came from below the piston ring in the crankcase. Heck, the working surface of your piston ring isn't even burnished or polished - it's not broken in. The gouges in your piston skirt may serve as good oil retention grooves. I would like to see what your cylinder sleve/bore looks like. Are there any abnormal marks on your piston crown?

Bill

Ram Jet

Hey, look at what you are learning. Total the sum of your expeses for the parts and weigh that against the experience you have gained in such a short period of time. I think you just got a bargain basement course in engine maintenance. I admire your perseverance and drive. A-lot guys wouldn't have even picked up a screwdiver to take the case apart.

Kudos,
Bill

Chancho

Ram Jet,

600 grit - I meant to get the rough spots off the inside of the case, excluding the bearing seats and seal faces. It’s hard to describe but right below where the crank counterweight swings in the bottom of the case there were hard metal chips ground into the aluminum case. I did my best last night to pick most of these ground-in chips out of the aluminum and then to smooth out the affected case area with a Dremel drill and wire wheel attachment. Again, I did not touch any of the bearing or seal mating surfaces. Somehow only a couple of these very small hard metal chips made it under the front bearing seat. I had to clean out these chips, too, and remove the burs from the bearing seat for anticipation of the new front bearing being able to sit properly. I feel confident the case will be fine.

The piston is junk. I did clean it with a rag to get to metal, but it was black on top. It cleaned easily. There were only a couple small scratches on top of the piston, but nothing like on the sides. I looked at the sides of the piston under 100, 200 and 400x magnification and saw what, from the naked eye, appear to be small scratches are actually gouges that are gorges. There are microscopic hard metal chips impregnated that would be impossible to get out without damaging and reducing the function of the head. Also I’m curious what manufacturing process Saito uses for their head. It appears they have manufactured horizontal lines perfectly around the full length of the piston. I assume these are for oil retention? What I can see under magnification, these lines go deep and thru the gouges that are there from damage. You cannot see them with your naked eye or reading glasses, but they are there.

I’ll try to get some decent pictures of the jug. It does have a couple bad scratches too. I just haven’t spent a lot of time with it besides staring at the obvious broken muffler pipe.
I just don’t know where in the heck the metal has come from. The only thing I can tell so far is that the inner race of the rear bearing has some of the material that appears to be lifted up in a few spots. That is going to take a hack saw to investigate further. The cage is still intact and the balls appear to be solid. It’s just amazing that this engine had been running so good a few days ago. It looked like only a matter of time before something major was going to give way from the metal in there. “Investigation is still pending.”

With your Enya and motorcycle repairs you’ve got a lot more experience than a lot of us, (like me...) Before this venture I didn’t know why you needed to put the connecting rod in the same orientation as you took it out. I’ve only taken apart a couple 2 strokes with no rhyme or reason as to the fact I was doing more harm than good by unseating the ring, turning the piston around, etc. etc. Good stories and good reading. Thanks for sharing!

….. Time spent reading, messaging and mailing on how to fix an engine,
= Enjoyable spare time spent…
….. $150 in parts to fix a broken engine
= “Don’t tell my wife”
….. Sense of accomplishment so far
= Priceless

Attached are a few pictures from my kids electronic magnifier...

Peace out,

Phil

w8ye

My Feedback: (16)

IMHO those are just machining marks but they do serve the function you suggest