EBGFLIGHT

If anybody is still viewing this thread for the original content..I just opened up my tank to find there is 1/2a fuel line being used for the pick-up. Is it possible that caused the lean condition that seized my con-rod? And yes I would prefer 2stokers after this seizing nonsense. Although I do have a P-34 with a st3000 I have yet to run. I need a high torque starter! Does anybody have a spare they can sell me? Thank - Eric

the pope

I have no idea what 1/2a tubing looks like but if its the cause of your drama then its not nonsense and hardly the fault of the engine . Everyone's done something dumb in this hobby so as long as we learn from it !!!! . You could have a thread 000;s of pages long on that subject . Its the dudes that do it every week that makes you chuckle .It would be a shame to be turned off of 4 strokes as there pretty cool . Cheers the pope

Rudolph Hart

Eric everyone is reading it and i'll give you ten bucks for the engine if you post it friend,i only offer the ten dollars because it would be a shame to see a nice saito fourstroke sitting on a shelf next to something sad like a two stroke.

Popey that's funny mate,would you like to kick off a thread on fourstroke engine handling bungles? we all know them but it's funny when people write it down,i've a few too.

the pope

Hi there O.F. my comment on the dumb stuff was aimed at modeling in general . I havent done too much dumb stuff , I had some good buddies that werent afraid to share their knowledge and I like to learn from the mistakes of others . Its cheaper that way . The best saying that i was told was that a mans got to know his limitations and I try to live by that rule except when it comes to the grog . When I changed clubs I rocked up one Sunday ( worst day , busy ) with my saito powered stik and being new all the peckerheads milled around and I was nervous to be begin with as I got filled with stories on how hard the field was because of trees bla bla bla . Anyway shes all fueled up and Im cranking on her with starter and the bloody thing wouldnt start and this is my most reliable and favorite engine . Turns out you need the glow igniter on it to start . Bang straight off the bat Im a drongo ! Now I know u must have some stories .Cheers

Rudolph Hart

"yeh i do" (pronounced like in that ray stevens song about a streaker 'ethel you get your clothes back on') it's a bugger when the big saito single fires first backflip and goes straight to full throttle,any ideas?

Hobbsy

My Feedback: (102)

Gents, EB is trying to get this thread back on track.
EB, in all my years of owning Saitos, since 1990 anyway, I've never seen a Saito lock up and most likely few others either. The 1/2-a fuel is a possibility, it might not let the mixture be as rich as needed. In my own experience I've used medium fuel tubing on everything from an LA .10 to a SuperTigre 4500 with no issues. Have you blown out the fuel passages in the carb, stuff can magically collect there even if we think it's not possible. EB, keep the questions coming, we'll gitter figgered out.

Pete, my strangest Saito episode was when I first got my little .30 and was breaking it in, it's almost too small for the PSP, so there is an option to bolt small engines on top of the clamp rails. I did that, once, the tiny 2-56 screws came out and the engine ended up hanging at a 45 degree angle in mid air held only by the fuel line and throttle rod. Naturally the throttle rod was pulling the carb wide open. I grabbed a big thick towel I keep handy when working with engines, pinched the fuel line and caught the engine before it fell.

w8ye

My Feedback: (16)

I've had a couple never run Saitos freeze up on me on the first run.

In both cases the rod was stuck on the crankpin.

With some oil and working back and forth, I saved both engines with no parts needed.

hsukaria

Now that's a helpful post. Along with the 1/4 throttle and replacing the 1/2A tubing. If you fly airplanes, you would love the Saitos and would hang up those sissy 2-strokes, or use them as boat anchors!!!

Rudolph Hart

That's interesting has anyone else you know had that,and what do you think the cause was?

Dave i share your fear maybe you were lucky the little 30 (i love them) was hung on by the throttle rod and fuel line,quite exciting what? had the same with my 115 but it tore itself right loose and went for an unauthorized blat round the shed ricocheting off walls and the floor with me standing in the middle halfway through a sip of beer,never spilt a drop

ps cost me a good 15x8 apc as well

Propworn

My Feedback: (3)

Think about how the lower end gets its lube. It relies on what blows by the piston during normal running. A YS on the other hand takes fuel into the crankcase like a 2 stroke does so the lower end always receives fuel first. When I start any 4 stroke that has been sitting for a while I always inject some oil into the crankcase vent and spin it with the electric starter to make sure there is oil throughout the bottom end. In fact it says this on page 4 of the manual under break in. If the rod has seized on the pin its from lack of lube.

In fact it doesn't mater what engine 2 or 4 stroke I make a habit with any new/unknown engine or one that has been sitting over the winter to remove the glo plug/spark plug and squirt some oil down the cylinder as well as into the carb and crankcase vent if there is one then turning it over by hand until it feels free and smooth. Then I will spin it with the starter to get most of the oil out of the cylinder. Replace the plug and start. Never had any problems with engines getting tight on first start up.

Dennis

blw

My Feedback: (3)

Yep, it will take something more to get a free repair. If you bought it within the past 3 years from a hobby shop maybe they have the transaction stored. Otherwise, from what I've always read here and elsewhere, it's a roll of the dice with your cash when you send it in.

I've always believed you should get a sheet detailing what was repaired/replaced.

blw

My Feedback: (3)

Since I'm a moderator I can read the censored posts and I honestly think it was all in good humor. All of the participants are known for their idiosyncrasies and we give them wide berth at times. Everybody waved the white flag.

Let's go lighter on the delete buttons in the future, okay? It's all about fun, information, and a bit of nonsense from time to time.

Propworn

My Feedback: (3)

Rebuilding these little gems (all model engines) gets to be a hobby in itself. It’s not that hard but very rewarding when you fire up your fresh rebuild to find all that lost power. Most of the time what people call a rebuild is simply putting new bearings in the thing. I remember re-bearing a competitors engine between rounds at a competition only to have him finish ahead of me in the later rounds. We used a cardboard bottom from a case of pop to contain the parts as we were at the field. Called the local bearing supply (it was Saturday morning first round) the guy stayed open past noon while he ran to the bearing supplier in town. Had the engine cleaned ready to go back together when he got back. Half an hour later it was back in the model and running. Didn't touch the carb or intake manifold left it on the cylinder. I have a neat tool to set the cam timing on the Saitos it’s a pin that goes into the lifter bore and the end fits in the hole in the cam shaft so it locks the cam in the proper alignment for timing at top dead center. Proper cam timing first time every time.

http://users.tpg.com.au/gmustang/sai...ng/timing.html

blw

My Feedback: (3)

Nice website.

Propworn

My Feedback: (3)

When the rod seizes on the crankshaft or pin you may get lucky breaking it free and just work it back and forth until it frees up enough to use. You have to pay close attention that nothing has galled the pins or stuck to the pin surfaces. If this has happened you can save the crankshaft or wrist pin by removing the material stuck to the surface. Realize this metal has come from the softer rod surface so it might be wise at this time to spend the money and replace the rod. In a pinch or where a customer just wanted it put back together many times the engine has run just fine. On a few occasions rod failure or noisy engine resulted in me looking at it a second time.

The only thing I can tell you is to use your judgment the cost or repairs vs., the consequences of the engine quitting at the most inopportune moment. My experience is failures of this kind never happen after one of your best landings while taxiing back to the pits. More likely just as your hanging on the prop 12 ft from the ground. LOL

Dennis

Rudolph Hart

Thanks dennis now i'm going to strip an engine and look at the rod and crank carefully,it's the only engine i have that is making the strangest sound and i've never been able to find it.It's very faint and sounds like a piece of cardboard being rubbed back and forth on a kitchen bench,or hand sanding primer if you are familiar with that.Very idiosyncratic

EBGFLIGHT

Thanks for all the replies. Ok, replaced 1/2a tubing in tank, and got new con rod that has upgraded slot(most likely cause imo). That's right! This new con rod I ordered has an extra slot for lubrication. Hmmm.. Anyway, should be solid now. One more thing to double check. What is the stock setting for the low speed for this .91? Just to make sure. Thanks

Propworn

My Feedback: (3)

2 or 4 stroke? When you have it apart roll the crankshaft using your thumb and finger by the prop end. It should turn silky smooth if you feel anything at all replace those bearings. If you had it apart before you may have put the rod back reversed. Usually the face of the rod that goes up against the crankshaft hole for the crank pin will have a small chamfer or radius for clearance for the small radius where the pin meets the crank. If this is reversed it will rub on the back plate.

Dennis.

Rudolph Hart

It's an 82 saito,when i changed the bearings the crank spun freely 3yrs ago flew the engine a couple of times and it made that sound on a low flyby too at half throttle so i could listen to it longer.I took the backplate off this arvo and sure enough the inside of the backplate is scuffed.The weekend is over for us here,will fix it during the week after work and let you know how it goes.I'm still going to have a good look at the rod and crank while it's apart.Many thanks for the help friend.

Thankyou for moderating the way you do barry

Hobbsy

My Feedback: (102)

I restored all of the , (all in fun) posts so you can have more fun.

Propworn

My Feedback: (3)

In the diagram figure 1 I always scribe a small R on the rod before I take the engine apart so it gets assembled in the same orientation.

Figure 2 shows why. Some engines the con rod has a chamfer on the crank end to clear the small radius where the pin is attached to the crankshaft. If this is reversed it can cause rubbing on the rear back plate sometimes the motor will become hard to turn over when the back plate is tightened.

Figure three is a common error when assembling with new bearings. Failure to completely seat the rear bearing in the bearing pocket. This can cause rubbing on the back plate and the noise you hear at low throttle setting. The preferred method is to press the bearing into the housing by itself using a tool that only puts pressure on the outer race. However most do not have the intended tooling to do that. So most slip the bearing over the crankshaft and use the front bearing to help with alignment and press the bearing in using the crankshaft. Be reasonable when you do this as the outer race is not supported and you are using the balls to do the press with. You still need to seat that bearing into the pocket all the way. I have used a drill press with a pointed steel rod that fits in the center of the rear of the crankshaft and a hardwood block with a hole for the prop end of the crankshaft and pressed the bearing home. There is more control and less chance of damaging the bearing this way than striking it with something to seat the bearing. Hope this helps.

Dennis pratt

Hobbsy

My Feedback: (102)

I use a carefully chosen socket and a small block of oak to push the rear bearing in until it stops, same in the front. I use no heat whether installing or removing.

wcmorrison

My Feedback: (2)

The stock location for the low speed needle is flush with the throttle arm. That will be rich. So with some time on the engine when you start to set the idle speed, you will crank it in. The high speed needle I believe is 2.5 turns out and that also will be rich. The engine may need to keep the igniter battery on it to continue to run that rich. But that is okay for the first 5 or t10 minutes of running. Then I would begin turning the highs speed needle in to set the max flow of fuel into the carb. Most engines will run at 1.5 turns out, in some Saito's that could be only one complete turn out. Once you have say 30 minutes of run time, you can begin to tune the high and low speed needles. I would use a TACH to set the high speed needle for max performance and back the RPM off 200 to 300 RPM to the rich side. Then start working on the idle screw. Take your time. Once the engines is set up it rarely needs to be changed.

Propworn

My Feedback: (3)

Done the same often enough. I have an awful lot of socket sets and sometimes you just cannot find one that fits. Luck of the draw. Carefully applied heat will not hurt anything and in some cases with really old engines where the casting is fragile it works wonders. Never with an open flame always in an oven or on a piece of steel on a hot plate. If its to hot to hold or keep your finger on it that's usually enough to get a tough bearing out. If I had to use heat to remove the bearing I use the same heat to install one.

I remember rebuilding old Harley's and the valve guides were pressed in the aluminium heads. Guides came in different over sizes depicted by rings on the guide. If one pressed them out cold you could count on having to go up 3 over sizes from the ones removed. Press them out after they reached 400 in the oven no problem only need to go to the next oversize. Had lots of guys try and save a few bucks and press them out themselves cold and they took enough metal with them the largest oversize available wasn't enough. Machining guides to work past the factory over sizes was a lot more expensive than if they had me do it in the first place.

Dennis

blw

My Feedback: (3)

Nice diagram, Propworn.

wcmorrison, I agree with a lot of your break in method, and to be honest, it will work fine your way. But, there's sometimes a better mousetrap, right? I think 1/16" below the throttle arm is the correct setting for the low speed set screw. Also, do peak your high speed needle when ready to set the low speed.....but leave it peaked. Don't reduce rpms any. If you need to make a couple of adjustments to the low speed, go back and peak your high speed again, and then continue with the low speed needle. Reduce about 300 rpm when you are finished tuning.