Digger44

My Feedback: (4)

Does anyone know of a good reliable repair shop for these motors. I know Horizon does service this motor but they charge $30.00 an hr. It's not under warranty but fairly new, bought it with a used Funtana. I would consider repairing it myself with some direction if anyone is willing to advise. I have no experience with 4-stroke engines and little with 2-stroke, I have disassembled and cleaned with success. The noise sounds like it is coming from the cam or the front bearing area. When turning the shaft you can feel metal catching and grinding. This may be a front bearing destroyed but I really am not sure. When running the motor, it sounds awful. Loud wonning or grinding. Just started this noise yesterday(somewhat lower noise) and kept getting worse. I did checked the valve lash and it was a little tight. Adjusted and tried again , no help. Any advise would be appreciated.
Thanks, Bob

w8ye

My Feedback: (16)

Sounds like a bad bearing?

William Robison

My Feedback: (3)

[b]Dig:

Agree. Bearing. Do not run the engine again until it is checked.

I'm currently doing an FA-91 for a fellow who ignored bad bearings - bad damage to the cylinder wall from bits of bearing caught in the piston. Looks like vertical file marks.

Go to the end of the "Club Saito" thread, I made a post there about Saito internal inspection yesterday. Includes the comment about the bearing failure and cylinder.

More questions, just ask.

Bill.

Digger44

My Feedback: (4)

Ok, This is what I found when I removed the back cover. Looks like bearing shield pieces got under the push rod and troughed the bottom of the case. I don't think this will be a problem, however, I am worried about fragments getting in the cylinder like Bill was saying. Can't see any damage from where I am right now, guess I'll have to disassemble to know for sure?? Back to the bearings, If this is all I find that has been damaged, Should I not go any further in replacing parts or is it better to replace other parts as well while I have it torn apart, such as valve springs, valves, gaskets, etc. What should be the minimum?? Any thoughts.
Thanks,
Bob

Rudeboy

You shouldn't have to replace anything that isn't damaged. A new gasket set may be needed after taking it apart.

From the looks of that picture you are going to have to do a complete tear down. First, to make sure you can clean out all metal bits thoroughly, and second, to be able to check all the parts properly for damage.
It is not unlikely other parts got damaged from the looks of it...[&o]

William Robison

My Feedback: (3)

[b]Bob:

With extreme enhancement I was able to see a little of the bearing (first picture) and what I see has the balls still in place, I can't tell is the cage has come apart.

In my thread "Can't believe it was still running" the bearing cage was still in one piece, there was enough radial play to let the connecting rod (not "Push" rod) hit the inside of the crankcase. Whether it's bearing disintegration or merely wear your con rod also was hitting the case. Second picture.

You also have damage to the con rod. Third picture. Inspect it carefully, yours is a forged rod and enough impact can weaken it. Best would be replafement. The case will be OK.

These pictures are crop and enlargement from the picture you posted.

Bill.

Digger44

My Feedback: (4)

I'll finish taking it apart so I can see all the possible damage. I would have never cought the connecting rod damage on my own. I need to get a better look at the cylinder wall. If it is damaged and or the crank is bent I might as well buy a new engine based on the prices for these parts at Horizon. As it is if I replace the connecting rod and the bearings it's around $50. I will get back with more pictures.
Thanks All

William Robison

My Feedback: (3)

[b]Bob:

I see no reason to suspect a bend in the crank, unless the bearing failure was caused by a crash. Even then the crank could be fine. If not, it can be straightened. The cylinder would put you up to a high repair cost, but still a lot less than a new engine.

If you do decide to replace instead of repair, I'd appreciate your sending the old one to me - it will go in my used parts bin. Or I might just fix it anyway.

Bill.

Digger44

My Feedback: (4)

Ok, I Have the motor broken down to the case and the bearings removed. Rear bearing definatly bad. Not sure about the front, probably a mute point. The cylinder walls look ok however I am not too sure. Anyway I have a few pictures of the peices and one of the puller that I picked up for $25 at Advance Auto. Might come in handy down the road.

Digger44

My Feedback: (4)

The wear that Will pointed out on one of the previous pictures is obvious in this one. Is this enough damage to concider replacement?

Digger44

My Feedback: (4)

The cam lobes don't look too bad, just dirty. Piston head seems normal. Am I missing anything here?

Digger44

My Feedback: (4)

bearings and puller

Digger44

My Feedback: (4)

Oh yea, The crank.

William Robison

My Feedback: (3)

[b]Bob:

You definitely had a retainer failure in the rear bearing. Overall, the engine appears to be low time - have you been running all synthetic and not using after run oil? Shame on you!

The rod doesn't look too bad, I'd polish the marks out of it to eliminate a groove for a crack to start, then if it's still reasonably close to original thickness I'd put it back in. The one I have here looked worse and I'm reusing it.

Your pictures don't show the cylinder wall at all well, you might want to get a close-up lens if you're going to continue taking detail pictures. Even a 4X jeweler's loupe held over the end of the lens gives sharp pictures at 3 inch distance. That's what I used for the ones attached.

First picture shows the cylinder wall, I stuck a bit of white paper in to kill the reflections, the vertical marks are some of the scoring. THey are deep enough to feel running your finger around inside the bore.

The other two pictures show where bits of metal were knocked out of the wall between the rear bearing and the cam chest.

New bearings? Go to http://www.rc-bearings.com/ and order a ceramic rear bearing, for the front specify a sealed bearing, not shielded. He doesn't yet stock sealed ceramics, you'll get a steel one there. No problem, the rear bearing is the one that really has to work. So long as you balance your propellors and the spinner, that is. You'll have to order by email or phone, I have not yet convinced Paul Macintosh to pack them in sets with the sealed bearing. You want the seal, since there is nothing other than the closure of the bearing to seal the front end, with an open or shielded bearing the oil will flow right out the front of the engine.

Enough for now.

Bill.

gjeffers

hey Bill, i have around 300 flights on my 100 since i made the same mistake,and you saved me from my sins. i have been using power master 15%-18%oil half castor, and using afterrun, and she still sounds sweeeet. Thanks again(thats almost exactly what mine looked like)[X(]

Digger44

My Feedback: (4)

Thanks Will, I ordered the ceramic rear and the sealed front bearing. Paul does have a VISA option on the web site now as well as Pay Pall. Couldn't find any options to split the two bearing package on the site, I called Paul and a note in the comments section of the order is all that is required.

You are right about the synthetic/ no Castor,[&o] Lesson learned. Caster from now on. Saito is sure confusing on their recommendations for fuel. Makes you wonder if the manuals !QUOT!fuel recommendations!QUOT! are worth reading. From what I have seen here on RCU they are NOT!!

New camera, don't know all the fancy macro settings yet, if I can't figure them out I will try the jeweler's loupe.
Thanks again.
Bob

William Robison

My Feedback: (3)

[b]Look. Read. Act.

Bill.

canadagoose

My Feedback: (2)

Hey Digger44, you're engine looks much better than my 80 did inside after my rear bearing cage became shrapnel 11 years ago (which was the engines second rear Saito bearing) . My piston had quite a few score marks in it, the cylinder walls being harder had some but weren't too bad. The conrod and crankcase were badly pitted and scored, anyways the only thing i repaced was the conrod and bearings, your conrod shouldn't need to be. I gave the cylinder a light honing with a brake cylinder hone, reseated the valves as some particles had made it past the piston and made the valves and seats leak, changed the bearings with some high quality high speed bearings, cleaned it up good and put it back together. After some running in, it has great compression and is my best running and starting 4C i have. Best thing you can do to a Saito is use castor oil in the fuel and change the Saito bearings for better ones. I mix my own fuel with 20% oil content (20% castor 80% synthetic).

Shogun

My Feedback: (2)

I had the same thing happen to my 100 and it had virtually identical damage. Take that engine and wash it with dish soap and HOT water to get as much of the oil residue out as possible. You want to get ALL of the small metal fragments out of the engine which means clean it till it's spotless, or as best you can.

I called Horizon customer service and inquired about the rear bearing part number as my LHS couldn't identify the proper part number and wound up ordering me the wrong part. The Horizon rep was great and after checking their computer to identify the proper number even he couldn't determine what it was. He tells me he is headed down to the engine shop and will get the number from the engine guys themselves and will be right back. Ten minutes later he comes back and says that indeed the number for that part isn't listed in the parts breakdown on any of their parts list and that the engine guys are the only one's that seemed to know what the part was that I needed. He said thay had some and asked me where I wanted it shipped to, I asked what it was going to cost and he said it was no charge. Now understand that I have had my 100 for well over 2 years so this wasn't warrantee and I told the guy so, he said no sweat and said it would go out ASAP.

Here's the really mind boggling part.....it showed up the NEXT afternoon! I was floored to say the least.

You might want to give them a call. I suspect that they have had a problem with this bearing and they are giving them away to anyone that asks for one. If the front bearing feels smooth just reuse it, the back one is the part that takes all of the load and will fail 9 times out of 10.

William Robison

My Feedback: (3)

[b]Scott:

I've always found Horizon very nice to deal with, and I'd not be surprised if Dennis Davenport was the man who gave you the bearing. He's one of the very best, I can not recommend hin too highly.

Bill.

Digger44

My Feedback: (4)

Thats a really good story Shogun, but I already ordered the higher quality ceramic Rear bearing from [link]http://www.rc-bearings.com/[/link]. If you are right about them being defective original bearings, then I don't think I would take a chance with them anyway unless there has been some sort of upgrade. I did call them to see what the charge would be for them to repair and they wanted $30/hr + parts. Thats what motivated me to try this repair myself. So far, with the help and info available here on RCU, I have learned a great deal about 4 stroke motors that I would not have learned otherwise.

I have cleaned the engine parts with AF and hope to receive the new front and rear bearings soon. Then the fun begins. I dont think I will have any trouble with most of the re-assemble, however the valve timing I may have to play with for a while. All in all, this has been a good learning experience. Hopefully it will continue through the running of the motor.

Digger44

My Feedback: (4)

The Morgan web [link]http://www.morganfuel.com/omega_blends.htm[/link] site listed the 15% Omega nitro blend castor/synthetic mix as 30/70 of 17% total oil. By my calculations this is a 5.1% castor to 11.9 % synthetic. Question, Is 5.1% enough castor or should I mix additional castor into the blend and if so, what should the castor % be? This site also suggests that if you add 1.2 oz of castor to the blend this will increase the blend % by 1% for every 1.2oz added. I am assuming they are talking about 1 gallon.

William Robison

My Feedback: (3)

[b]Bob:

My fuel of choice is Omega 15% straight out of the jug. I've not had any damage that could be blamed on lube failure since I started using it in place of a higher percentage castor oil. I'd say it is fine as it is.

A new engine gets 2 ounces of castor oil added to the first gallon of fuel.

Please note this "Stock" Omega recommendation holds only for Saito engines, and others with chromed cylinder bores and the cranks mounted with ball bearings.

In other words Omega is fine also in a true ABC two stroke with a ball bearing mounted crank.

Engines with a plain bearing crank, like the older Magnum GP or the OS FP and LA series, need a higher percentage of castor oil. The synthetic does not have the lubricating qualities needed for the crank bearing.

When you get to the really old style piston and cylinder design, a meehanite piston in a steel cylinder, the lubrication should be 100% castor oil. Another example is the common Cox engine, not only iron piston and sleeve, but a sleeve bearing crank as well.

Bill.

N1EDM

My Feedback: (2)

Digger44,

Just a quick note here (if I can jump in for a second, and if no one else has mentioned it) be sure to line up your timing marks on the cam with the crankshaft when you re-assemble. I've heard of guys using roll pins as a timing tool, to help with that. Perhaps Bill Robison might want to expand on that...

Bob

William Robison

My Feedback: (3)

[b]Bob:

If you think you have something to add, don't hesitate to jump in. Some may think you're wrong, but that's their problem, not yours.

Haw.

This time, at least, you do have a good point. However, in the FA-100 engine the timing pin can't be used - it has the mushroom tappets that have to be installed before the cam is installed. Use of the timing pin requires the intake tappet to be installed from the outside after the pin is pulled out. First picture, conventional tubular tappets that allow using the pin, second is the mushroomed tappets.

Third picture shows the cam gear, below the "S" there's a drill mark. The gear tooth indicated by the mark is to be centered on the crank gear with the piston at top dead center.

What makes the cam installation a pain is the free turning of the cam, just barely touch it on the case as you drop it in place and it will turn, be out of time, and you wont know it until you recheck after you fasten it down. Then you pull it out and try again.I don't remember who suggested it, but it was a user here on RCU who told me the "Easy" way for installing the late cams.

With the crank case and installed crank shaft mounted in your test stand, or lightly clamped in a vise, turn the cam to get the timing mark straight down, then use your X-Acto knife with a #11 blade to hold the gear, the blade against the gasket face, and set the assembly into the crank case. Check the timing, if OK continue with the assembly of the engine.

Check the timing? How? Easy. Get your push rods out, remembering to keep the exhaust and intake separate. Now while the engine is still on the stand/in the vise, set the push rods into the tappets. Use your left index finger to push the inlet rod in, and your left middle finger to push the exhaust rod. With your right hand turn the crank in its normal direction of rotation. After about 1/2 turn you will feel your middle finger (exhaust) being pushed up, then as you complete one full turn your middle finger will be going back down and the index finger will be pushed up. The crank should have the crank pin at the top, centered in the opening for the cylinder mounting. Rock the crank, you'll feel your two fingers going up and down one opposite the other - as one rises the other will fall. The center point with both fingers equally displaced should be with the crank pin in its center position. This is exactly the same as observing the valve rocker movement with the engine completely assembled, you're just doing it without having the rockers installed. Sorry, I don't have any pictures of this procedure. If wanted/desired I can shoot some, but I'll have to pull an engine apart to do it.

Hope no body is too confused by all this, if you are, or just want clarification of a point, please ask.

Bill.