w8ye

My Feedback: (16)

We can still help you. Just ask away

cubfloater

My Feedback: (5)

Thanks w8ye, matter of fact I believe I took your advice on the bearings source. They are so cheap and if this goes as planned I'd think finding cheap old non-crash damaged engines might not be a bad thing. As long as not too old and parts still available. You can pick them up cheap at swap meets. I love getting an engine that is seized up. Lots don't know that the fuel is only gummed up. And don't worry, I plan to ask.

Jim

Ernie Misner

Should be quite a bit about the cam timing in the William Robison Comeplete Saito Notes at the top of the Engines forum.

Ernie

cubfloater

My Feedback: (5)

Duh... thanks Ernie I didn't even think about Bill's notes. I've looked through them before and know there's lots of great info there. Probably more than I'll ever need. And I had to even skip right over it to get to this thread! I'll go to it now and start reading while waiting on my bearings to arrive. Will check in later if I get stumped. Probably will, not quite an engineer but my brother is. I do like fiddling with things. Thanks again Ernie.

Jim

Ernie Misner

It's great to keep getting use out of Bill's notes! When the cam timing is correct, both valves will be slightly open when the piston is at TDC... not on the compression stroke.... Not that that is how to set the timing in the first place though. Keep us posted, your enthusiasm is contagious ~

Ernie Misner

radial1951

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Aha!! Now we ALL know.

There goes the bargains...
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johnfly

ok.. Thanks guys.

maverick11359

Sorry to jump in i could not find a new thread to start a post.

I have a saito FA82b which has warn out its bearings ..it has had over 200 hours fly time which doesn't seem very long for bearings having always used after run oil.. I've pulled the engine apart but have come to a stop on removing the prop back drive washer to pull out the crank shaft . it appears to have a brass sleave or collar ..How do I disasemble it ? Do I need to use and buy a puller ,is their one avaliable for Saito engines ? Any ideas are appreciated.

cheers Rick.

earlwb

Since you are replacing the bearings anyway. What I do is heat up the crankcase and drive washer especially and then I whack the crankshaft end pushing it back and down or out through the back. As soon as the crankshaft moves a little, the drive washer comes right off. I then reheat the crankcase and continue until I get it out. If the bearing comes out great, otherwise I use a brass rod that has a lip on it catch the inside of the bearing to  go around the edge and tap it out. Same for the front bearing but it gets tapped out to the front of course. Sometimes the bearings are in there pretty tight. I use a brass hammer to get the things apart.

The methods used for a two stroke engine works on a four stroke, albeit you need to remove the camshaft assembly so it is out of the way too.
Here is a good video on how to do it. Some engine are pretty easy to do this to, other engines need some extra effort to get the bearings out.

http://www.rcmodelreviews.com/bearings.shtml

You can you a drive washer puller, but a small bearing splitter tool works equally well.

Mein Duff

I recently removed the prop driver washer ( as you describe) simply with a small gear puller ...took me a while to find one with long enough chuck to extend fa enough down. Didn't even heat the case ( but would rceommend it anyway next time )...my first time also... went well.

maverick11359

Thanks for the advice guys,

Rudolph Hart

Would you re-read earls post first?

Ernie Misner

Is everyone running the velocity stack on their Saitos? I have an 82 that I installed the optional stack on but haven't got one on the 125 yet. Should I bother with it? I know they were really popular a couple of years ago and everyone said you'd get less spit back mess and better mileage.

Also how often do you change the Viton O-ring where the intake manifold goes into the head? Does it tend to go bad eventually on it's own or is it taking the manifold off and on that takes it's toll on that o-ring? I ask because my 82 dead sticked a couple of times lately and I haven't pin pointed the cause yet. Could just have been the tank foaming on the profile plane though.

Thanks,

Ernie Misner

w8ye

My Feedback: (16)

If you are running a plastic back plate on your 72 and 82, you should change the Viton O ring at least once a year. The 72 is worse than the 82.

On the 82 with the aluminum back plate, the O ring should last for years.

I don't run velocity stacks on the 125's but the others I do.

maverick11359

Old Fart,  I can read and i can re read Earls post but his method didn't work for me in this case. Earl's method is my method on my OS engines . I already tried Earls method  twice the day before i wrote the post  .Unless I try a third time and possibly whack my crank shaft with a lump hammer instead of my metal ball  hammer  while heating it with my heat gun( i don't think so ). 

w8ye

My Feedback: (16)

On some Saito engines the drive hub is really hard to break loose. I use a good puller and sometimes the heat too.

Rudolph Hart

Hey no offence intended rick.Sounds like the way to go and will be trying it myself.I usually use a gear puller but tapping the crank back and taking the bearings with it appeals to a lazy bugger like me

Ernie i use velocity stacks and agree with your comments.On my 82 i've had a couple of deadsticks but only when there is something violent going on flying wise.

Mein Duff

I found my gear puller at the local Car parts distributor, Kragans ( now O'Reilly's)...was around 10 $..... had to use a round file on the puller jaws to get the best possible seating around the back of the prop driver ...there is only about a 1mm lip that protrudes on the small Saitos ...

w8ye

My Feedback: (16)

I clamp a bearing separator around the hub and use the puller against the bearing separator.

http://www.harborfreight.com/bearing...set-93980.html

Ernie Misner

Has anyone identified the usual symptom when that Viton O-ring starts to go? Would it show up more at idle?

Thanks again,

Ernie Misner

w8ye

My Feedback: (16)

It effects the idle more than any other speed.

Biggest symptom is that you have to keep changing the mixture. It will jump to too lean and then you will determine it is too rich, etc.

spaceworm

+1 on the bearing splitter. I bought a small one from HF separate from the whole set a few years back.

Ernie Misner

>>> Biggest symptom is that you have to keep changing the mixture. It will jump to too lean and then you will determine it is too rich, etc. >>>

Thanks Jim, has anyone found a way to buy just the Viton O-rings without purchasing a whole gasket set????

Thanks,

Ernie

radial1951

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Hi Ernie,

Any engineering supply or bearing shop should sell viton o-rings, they are a standard product line for high temp applications. I assume being for a Saito they will be metric, no problem here in Oz, but in the USA?

Just make sure they are Viton, usually orangey-reddish-brown or grey (gray :-), but NEVER black.

Regards, RossG
radial1951
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Ernie Misner

Thanks RossG! Let's see if we can come up with some metric dimensions for that Viton O-ring for the popular size Saitos. My 2 saitos are the 82 and 125, which might? even have the same size intake manifold but that would be pushing my luck.

Thanks,

Ernie Misner