Welcome to Club SAITO !
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RE: Welcome to Club SAITO !
ORIGINAL: hsukaria
I'm considering purchasing a used Saito for a Sig Rascal 40. I just had a Magnum 52 RFS on it, but was not enough power to call it a sports plane. What would be a good Saito candidate? Realize that the Rascal 40 has a wood cowl integral to the fuselage, so I can't go too big.
Thanks.
I'm considering purchasing a used Saito for a Sig Rascal 40. I just had a Magnum 52 RFS on it, but was not enough power to call it a sports plane. What would be a good Saito candidate? Realize that the Rascal 40 has a wood cowl integral to the fuselage, so I can't go too big.
Thanks.
Look at the specifications table in this link, and you can then measure your Rascal 40 to see if you could make it fit:
[link=http://saito-engines.info/specifications.html]Saito Specifications[/link]
In any case, you can use that table to determine what engine will fit in your cowl. Hope it helps!
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RE: Welcome to Club SAITO !
ORIGINAL: w8ye
Try Bill's valve lash settings? The engine will not idle for toot and the high speed will be weak.
.002'' cold is about it.
Try Bill's valve lash settings? The engine will not idle for toot and the high speed will be weak.
.002'' cold is about it.
Just for the sake of knowing, I may try comparing an engine on the test stand at different valve lash settings to see if performance changes. Might be interesting!
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RE: Welcome to Club SAITO !
ORIGINAL: Ken6PPC
Yes, I did try setting valve lash to 0.0005'' on one of my 1.25's, and I did have trouble getting it to idle well. It didn't start easily either. I opened them back up to just under 0.002'', and I was pleased with the performance there.
Just for the sake of knowing, I may try comparing an engine on the test stand at different valve lash settings to see if performance changes. Might be interesting!
ORIGINAL: w8ye
Try Bill's valve lash settings? The engine will not idle for toot and the high speed will be weak.
.002'' cold is about it.
Try Bill's valve lash settings? The engine will not idle for toot and the high speed will be weak.
.002'' cold is about it.
Just for the sake of knowing, I may try comparing an engine on the test stand at different valve lash settings to see if performance changes. Might be interesting!
Gotta wonder if setting lash that tight with ramps doesn't increase the duration enough to hinder the idle.
@Hobbsy, I didn't feel a burr but that might be it.
Cory
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RE: Welcome to Club SAITO !
My thinking says that the weak top end as Jim describes it would be cause by the overlap period being longer and causing the equivalent of a lean mixture. This would be caused by excessive blow back through the carb. The intake and exhaust valves are both open from about 11:00 o-clock to about 1:00 at the end of the exhaust and the beginning of the intake strokes. Less lash exaggerates the overlap period.
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RE: Welcome to Club SAITO !
Yep, that's what I'm thinking. With rampless profile, setting them tighter will change the duration very very little and effect the overlap twice as much as very very little. But the profile of the ramps greatly spreads out the width of the lobe, so every thousandths of lash you take out quickly increases the duration, and double quickly increases the overlap.
Cory
Cory
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RE: Welcome to Club SAITO !
Concerning this business of valve clearences n(and fuel mixes) it appears to me that this "confusion" / discussion could have international inferences. Take the fuel thing, our instructions are different to the USA and other places, likewise the valve clearence thing. It was alluded elsewhere that the Saito people (and their reps) take into account the end user when issuing instructions.
Me for general use I always follow the manufacturer except when I am "racing" and finances permitting I usually purchase 2 of the racing engine that I am about to modify / re tune and keep the other stock as a reference point. Expensive yes but I do have a pristine NIB collection of diesels (Burfords and ED's) and Glo's such as Rossi 40, ST 40 (with pipe) and the OS 40PS and the racing Irvines.
What I am leading up to hear is unless there is need to follow the manufactuers specs it is designed to get the optimum out of the engine and if it breaks back it goes under warrenty. If you mess with it outside the manufacturers parameters by by warrenty.
Keep up the conversation on this and for my 2 bob's worth (20 cents to the US and 20p to UK) I run the until the engine is hot and then set the rocker clearence to a tight fit of the factory guage and the adjust the Hs mixture according to what I want the engine to do. And in duration I use new plugs and a tight gap combined with a "medium" needle valve setting for max rpm for the prop combination.
Me for general use I always follow the manufacturer except when I am "racing" and finances permitting I usually purchase 2 of the racing engine that I am about to modify / re tune and keep the other stock as a reference point. Expensive yes but I do have a pristine NIB collection of diesels (Burfords and ED's) and Glo's such as Rossi 40, ST 40 (with pipe) and the OS 40PS and the racing Irvines.
What I am leading up to hear is unless there is need to follow the manufactuers specs it is designed to get the optimum out of the engine and if it breaks back it goes under warrenty. If you mess with it outside the manufacturers parameters by by warrenty.
Keep up the conversation on this and for my 2 bob's worth (20 cents to the US and 20p to UK) I run the until the engine is hot and then set the rocker clearence to a tight fit of the factory guage and the adjust the Hs mixture according to what I want the engine to do. And in duration I use new plugs and a tight gap combined with a "medium" needle valve setting for max rpm for the prop combination.
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RE: Welcome to Club SAITO !
That last post reads a bit ragged, follow the manufacturers specs for general / sport use vary at you pocket book peril. Back to the birthday celebrations, Pear cider plus all the local goodies are the go for this newly minted 62 year old
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RE: Welcome to Club SAITO !
Well after 3 flights with my new Saito 125 my Yak fell right out of the sky and happened to hit on the road thereby shearing the muffler manifold off at the cylinder and an entire rocker arm assembly. I can take losing an airframe - it's expected from time to time, but it hurts to do that much damage to a new $400 engine. Looks like the crankshaft may be OK, but I'll be needing a new top end.Question is can the top end be replaced without complete disassembly given the crank is OK.Is there anywhere in the thread describing procedure for the upper end rocker/pushrod disassembly?
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RE: Welcome to Club SAITO !
The cylinder is a $125 hit. if you destroyed the rocker arm pivots on one side?
The valve covers are expensive if they are gold plated.
Some of the old parts can be used on the new cylinder head.
The valve covers are expensive if they are gold plated.
Some of the old parts can be used on the new cylinder head.
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RE: Welcome to Club SAITO !
working on saitos is fun. but often expensive to replace parts. Post some photos on here and lots of folks can walk you through it.
RE: Welcome to Club SAITO !
ORIGINAL: mike early
working on saitos is fun. but often expensive to replace parts. Post some photos on here and lots of folks can walk you through it.
working on saitos is fun. but often expensive to replace parts. Post some photos on here and lots of folks can walk you through it.
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RE: Welcome to Club SAITO !
OK, here's the post mortem,
Parts List.
Parts List.
Cylinder
Gasket Set
Rocker Arm
Rocker Arm Nuts
Rocker Arm Pins
Rocker Covers
Cylinder Screw Set (for cover screws)
Pushrod Covers w/Rub Seal
$171 Total (Ouch), Look Complete?
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RE: Welcome to Club SAITO !
Cylinder $116.99
http://www.horizonhobby.com/Products...dID=SAI125A01A
Rocker arms $15.15
http://www.horizonhobby.com/Products...ProdID=SAI5041
Rocker arm adjusting nuts $4.75
http://www.horizonhobby.com/Products...ProdID=SAI5042
Rocker arm pivot pins $3.75
http://www.horizonhobby.com/Products...ProdID=SAI5043
Rocker Covers $15.15
http://www.horizonhobby.com/Products...rodID=SAI5049A
Cylinder screws $2.15
http://www.horizonhobby.com/Products...ProdID=SAI6514
Valve cover gaskets $4.99
http://www.horizonhobby.com/Products...odID=SAI125A32
Push rod tubes $7.99
http://www.horizonhobby.com/Products...odID=SAI90TS40
http://www.horizonhobby.com/Products...dID=SAI125A01A
Rocker arms $15.15
http://www.horizonhobby.com/Products...ProdID=SAI5041
Rocker arm adjusting nuts $4.75
http://www.horizonhobby.com/Products...ProdID=SAI5042
Rocker arm pivot pins $3.75
http://www.horizonhobby.com/Products...ProdID=SAI5043
Rocker Covers $15.15
http://www.horizonhobby.com/Products...rodID=SAI5049A
Cylinder screws $2.15
http://www.horizonhobby.com/Products...ProdID=SAI6514
Valve cover gaskets $4.99
http://www.horizonhobby.com/Products...odID=SAI125A32
Push rod tubes $7.99
http://www.horizonhobby.com/Products...odID=SAI90TS40
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RE: Welcome to Club SAITO !
Looks Like we match on the parts list. Does the cylinder just sit down on top of the the pushrods/pushrod covers and then you assemble the rocker arm assembly? Anything special to compress the piston ring when lowering the cylinder? And anything I need to know about installing the valves in the head? Never disassembled a Saito before. Thanks for the assist.
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RE: Welcome to Club SAITO !
The cylinder just sits down on top of everything. You can nudge the ring inside the cylinder with your fingernails.
The hardest part is setting the old head down over a screwdriver handle with the screwdriver shank held in a vice. This is to hold the valves closed while you take the springs off.
You push the valve spring retainer down with a open pair of needle nose pliers and slide the retaining clip off with a small shirt pocket screw driver. This little clip will fly off into parts un known so be careful or do it inside a clear plastic bag to catch the clip?
Then you have to slide the valve out of the head. This is sometimes difficult for the valves will have a lip on them at the top of the keeper grove and at the very tip where the rocker arm taps it. You will have to take this lip off before putting the old valves in a new head.
Then you put the new head down over the screw driver handle with the valves in it and reassemble the springs.
Then you will have to adjust the valves
A guy brought me a 125 that his brother in law had put a new cylinder on. It had absolutely no compression. There is a wax on the valve seats. I had to take the cylinder all apart again and clean the valve seats with a little dot of tooth paste on each valve to get the wax off the valve seats. Sort of like lapping the valves. I spun the valves by putting a pin vice on the stems.
The hardest part is setting the old head down over a screwdriver handle with the screwdriver shank held in a vice. This is to hold the valves closed while you take the springs off.
You push the valve spring retainer down with a open pair of needle nose pliers and slide the retaining clip off with a small shirt pocket screw driver. This little clip will fly off into parts un known so be careful or do it inside a clear plastic bag to catch the clip?
Then you have to slide the valve out of the head. This is sometimes difficult for the valves will have a lip on them at the top of the keeper grove and at the very tip where the rocker arm taps it. You will have to take this lip off before putting the old valves in a new head.
Then you put the new head down over the screw driver handle with the valves in it and reassemble the springs.
Then you will have to adjust the valves
A guy brought me a 125 that his brother in law had put a new cylinder on. It had absolutely no compression. There is a wax on the valve seats. I had to take the cylinder all apart again and clean the valve seats with a little dot of tooth paste on each valve to get the wax off the valve seats. Sort of like lapping the valves. I spun the valves by putting a pin vice on the stems.
RE: Welcome to Club SAITO !
ORIGINAL: Linkan2
This tool makes it easy to change springs
Lars
This tool makes it easy to change springs
Lars
Or, if you don't otherwise have to remove the cylinder, you could thread some light cord through the plug hole with the piston down and then gently raise the piston allowing the cord to fill the space under the valves and hold them in place while you change the springs or keepers.
Richard
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RE: Welcome to Club SAITO !
Update on the crashed 125. Determined bent crank and at least one distorted ball bearing in additon to above. Price to repair now almost 90% of new engine. Sadly it looks like it's finished.