Welcome to Club SAITO !
12-28-2018, 07:31 PM
12-28-2018, 07:43 PM
Not sure about the fella with the 100 but my 82 is hissing out of the intake port. I put my ear up to the ports while turning the crank through the compression stroke, very audible hissing from the intake port, nothing from the exhaust port. I can hear air moving through the ring gap if I put my ear at the vent nipple, as normal.
12-28-2018, 07:44 PM
My Feedback: (1)
hummm, I guess, to make sure it IS your valves that are leaking, you can fill the valve's cavity with a light oil, then turn the crank on it's compression stroke to see if there are air bubbles in the oil
Jim
Jim
12-28-2018, 07:56 PM
My Feedback: (1)
Not sure about the fella with the 100 but my 82 is hissing out of the intake port. I put my ear up to the ports while turning the crank through the compression stroke, very audible hissing from the intake port, nothing from the exhaust port. I can hear air moving through the ring gap if I put my ear at the vent nipple, as normal.
OK then. you can ether re-seat the valve or try a new valve,
as for the Crank and Rod, boy that is a tuff one, you can run it as Dave says or buy a new Rod and Crank, I looked it up, a Rod is only $15, but the Crank is $62
Jim
12-28-2018, 08:39 PM
If you lightly lap the valve, clean well and have a look at the valve face. You should see a continuous band with a very consistent width defining the actual contact area. Don't fret too much about the leakage you may hear. Run the bugger a while, they often do improve, especially the intake. Odds are any leakage you have on the intake side are from a slightly bent valve, not any seat problems. Trying a fresh valve is about the cheapest test. Take off the intake tube, hold a greased finger tightly against the intake port DURING THE COMPRESSION STROKE. If you notice a big bump in compression, that is the leaky spot. You already know that from listening of course, but this test gives a good idea just how much. Yet, by running and checking RPM, you may find it isn't really hurting performance.
My comment about lapping the rod was just a caution against that!
If you have a badly scored crankpin you will likely wind up looking for a crank and rod as the scoring usually affects both.You may be able to get by with stoning down any minor high spot if the scoring is not severe. Hard to say without seeing and/or measuring. Running a bad pin and rod may cost you the entiere engine at some point if the rod lets go.
My comment about lapping the rod was just a caution against that!
If you have a badly scored crankpin you will likely wind up looking for a crank and rod as the scoring usually affects both.You may be able to get by with stoning down any minor high spot if the scoring is not severe. Hard to say without seeing and/or measuring. Running a bad pin and rod may cost you the entiere engine at some point if the rod lets go.
12-28-2018, 08:39 PM
My 100 definitely has a leaking intake valve. Compression leaks down somewhat quickly when turning over by hand. When I put my thumb over the exhaust port, no change in compression. When I put my thumb over the carb opening, compression increases considerably.
12-28-2018, 08:41 PM
Jim, I was just offering the 100 as a sub for the 90.
No problem, I do have a use for it
Hope you guys have a great season next year.
Had a good time here, at times.
No problem, I do have a use for it
Hope you guys have a great season next year.Had a good time here, at times.
12-28-2018, 08:43 PM
Bye
Last edited by Jesse Open; 12-28-2018 at 08:47 PM.
12-29-2018, 04:04 AM
My Feedback: (102)
Join Date: Dec 2001
Location: Colonial Beach, VA
Posts: 20,370
Likes: 0
Received 25 Likes
on
25 Posts
Not sure about the fella with the 100 but my 82 is hissing out of the intake port. I put my ear up to the ports while turning the crank through the compression stroke, very audible hissing from the intake port, nothing from the exhaust port. I can hear air moving through the ring gap if I put my ear at the vent nipple, as normal.
Jim, if that's the 82-a you got from me you might want to check the rocker lash, I set them with the .04 mm/.0015" OS gauge. I worry that that is too tight, but others love those close settings.
Last edited by Hobbsy; 12-29-2018 at 04:37 AM. Reason: Correct spelling
12-29-2018, 04:25 AM
My Feedback: (102)
Join Date: Dec 2001
Location: Colonial Beach, VA
Posts: 20,370
Likes: 0
Received 25 Likes
on
25 Posts
hey Dave, can you tell me why the 82GK uses different valves than the standard model ?? 82A #90s46,, 82aGK #91s46
now I know you find swapping Saito parts around is interesting, well>>> remember how "Captcrunch44" said he bought a used Saito 65 and it didn't have a carb and intake manifold, so he put an 80 carb and manifold on it, and he had a substantial power increase. he reported that it would turn a 13X6 at 11200RPM’s, well my OS 61FX would only turn an APC 12X6 at 10600 with the old Slimline Pitts on 20%..
well I found myself standing in front of my 82, I had not yet remounted the carb. so there I was standing there looking at the carb in the hand, and I could not resist, it was eating at me, I had to know, so I removed the 100's carb to see, and I found that the 100's carb ID is about .40mm larger than the 82's carb (my yellow plastic calipers only read in 1mm increments, and as I said I dropped my metal calipers so I could not get an accurate reading), never the less the 100's carb is almost 1/2 mm larger than the 82's carb,,
now the 82's intake OD is too small for the 100's carb, but the 100's manifold will fit the 82's engine head, but you have to shorten the 100's manifold,
so, in short, if you shorten the 100's manifold you can put the 100's larger carb on the 82,,, slick. it sounds like fun to me, so I will just have to try that some time, hey, maybe I will just buy a new 100 carb and manifold ?
one more thing, according to my "2008" Saito manual, all engines from the 62 to the 125 use the same "6547" valve springs and retainers, so I would think the springs should hold up
Jim
Saito engines are the thing
now I know you find swapping Saito parts around is interesting, well>>> remember how "Captcrunch44" said he bought a used Saito 65 and it didn't have a carb and intake manifold, so he put an 80 carb and manifold on it, and he had a substantial power increase. he reported that it would turn a 13X6 at 11200RPM’s, well my OS 61FX would only turn an APC 12X6 at 10600 with the old Slimline Pitts on 20%..
well I found myself standing in front of my 82, I had not yet remounted the carb. so there I was standing there looking at the carb in the hand, and I could not resist, it was eating at me, I had to know, so I removed the 100's carb to see, and I found that the 100's carb ID is about .40mm larger than the 82's carb (my yellow plastic calipers only read in 1mm increments, and as I said I dropped my metal calipers so I could not get an accurate reading), never the less the 100's carb is almost 1/2 mm larger than the 82's carb,,
now the 82's intake OD is too small for the 100's carb, but the 100's manifold will fit the 82's engine head, but you have to shorten the 100's manifold,
so, in short, if you shorten the 100's manifold you can put the 100's larger carb on the 82,,, slick. it sounds like fun to me, so I will just have to try that some time, hey, maybe I will just buy a new 100 carb and manifold ?
one more thing, according to my "2008" Saito manual, all engines from the 62 to the 125 use the same "6547" valve springs and retainers, so I would think the springs should hold up
Jim
Saito engines are the thing
Jim, we've been in and out so much I'm playing catch up.Those valves are all lumped together here: Saito Engines Valve In/Out:K,DD,EE SAI91S46 is compatible with SAIE082A, SAIE082B, SAIE082BGK, SAIE091S, SAIE091SGK, SAIE182TD, SAIE200TI, SAIEG14B, SAIEG14C A footnote to the specs.
I owned a 91-S GK for about a month, then the 100 came out so I traded the 91-S for a Joss Stock 90 and bought a 100.
Last edited by Hobbsy; 12-29-2018 at 04:34 AM.
12-29-2018, 04:48 AM
My Feedback: (102)
Join Date: Dec 2001
Location: Colonial Beach, VA
Posts: 20,370
Likes: 0
Received 25 Likes
on
25 Posts
Perhaps a moderator would tell us how many people regularly view these posts,i see regular comments from half a dozen people but there may be many more who just view and are helped by your knowledge gary.I won't insult you and say think about it as i'm sure you already have.Bear with me for a sec please.I like flying a good sounding saito fourstroke no matter what size,and hearing it go past,it's a reward for the time it took to fit that saito in an aeroplane you like.Your long post on your mechanical history although it mostly involved motorcycle engines gave me a sense of your experience and a willingness to listen to your opinion,saito engines ARE fourstrokes,i think it's a valid tell to others of your past experience...slap me if i'm wrong!! 
Pete, there was a time when all the current viewers were listed at the top of these pages, it varied from 20 to 50 names. Sometimes only one or two but that was rare.
12-29-2018, 06:22 AM
Trying a fresh valve is about the cheapest test. Take off the intake tube, hold a greased finger tightly against the intake port DURING THE COMPRESSION STROKE. If you notice a big bump in compression, that is the leaky spot. You already know that from listening of course, but this test gives a good idea just how much. Yet, by running and checking RPM, you may find it isn't really hurting performance.
I'll try to get some crank pin and rod pics uploaded today, and anything else I find.
12-29-2018, 06:29 AM
My Feedback: (102)
Join Date: Dec 2001
Location: Colonial Beach, VA
Posts: 20,370
Likes: 0
Received 25 Likes
on
25 Posts
My numbers for an 82-B unknown run time
Prop===Graupner G-Sonic 14 x 6
Plug===Fox Miracle
Fuel===Wildcat 10% with 18% full synthetic
Max rpm=9,150
Idle rpm=1,770
Last edited by Hobbsy; 12-29-2018 at 06:41 AM.
12-29-2018, 09:16 AM
My Feedback: (102)
Join Date: Dec 2001
Location: Colonial Beach, VA
Posts: 20,370
Likes: 0
Received 25 Likes
on
25 Posts
Rowdog that was worth the wait,love that sound.Is there a taylorcraft that would suit the fa90 twin rather than a cub if you like aerobatics? eg,i have a h9 82" taylorcraft and the recommended saito is an fa125,mine has an fa182 twin and is good fun to fly aerobatics with that sort of power,what do you think.
I had a chance to check out the Saito 120 DP I bought a while back, the carb mounts differently than any other Saito having two O-rings on the pipe and a steel bracket that bolts to the two upper back plate bolts. It has a rather long velocity stack. I need to run it.
12-29-2018, 11:19 AM
So I swapped the valves around in this 82 and the leaking problem did not follow the valve and I cannot find any inclusions on the intake seat that would cause the leaking. I must have taken 30 pics of the seat from all angles and I just don't see anything. Oh well, maybe Saito didn't machine the seat exactly perpendicular to the valve guide hole? Or maybe I just missed something? I'll find out tomorrow when I lap it using 3M Perfect-It ultra fine polishing compound. That will shine up all the high spots and make it easy to see what's going on.
How does the crank pin and rod look to you all? Is the crank salvageable with a fine stone and a light buff with 600 grit emery cloth?
How does the crank pin and rod look to you all? Is the crank salvageable with a fine stone and a light buff with 600 grit emery cloth?
Last edited by Glowgeek; 12-29-2018 at 11:33 AM.
12-29-2018, 11:44 AM
12-29-2018, 11:50 AM
My Feedback: (102)
Join Date: Dec 2001
Location: Colonial Beach, VA
Posts: 20,370
Likes: 0
Received 25 Likes
on
25 Posts
I just ran the big 120 for 50 minutes.
Saito 120 DP
Fuel===Wildcat 10% with 18% full syn.
Glow plugs==Dual Fox Miracles
Prop====Graupner G-Sonic 15 x 8
Exhaust==Latest Revised cast muffler
Max rpm==9,210, rock steady
Idle, 2,500 but not really attempted
Nice and smooth running, no kick backs, I was careful with the priming.
Saito 120 DP
Fuel===Wildcat 10% with 18% full syn.
Glow plugs==Dual Fox Miracles
Prop====Graupner G-Sonic 15 x 8
Exhaust==Latest Revised cast muffler
Max rpm==9,210, rock steady
Idle, 2,500 but not really attempted
Nice and smooth running, no kick backs, I was careful with the priming.
12-29-2018, 11:56 AM
My Feedback: (102)
Join Date: Dec 2001
Location: Colonial Beach, VA
Posts: 20,370
Likes: 0
Received 25 Likes
on
25 Posts
In that port picture between the 9:00 to 11:00 position the castor is mighty close to the wall of the intake port. Also, at midnight the seat appears to be wider than elsewhere. Might be an optical illusion though.