Welcome to Club SAITO !
03-03-2015, 12:40 PM
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03-03-2015, 03:26 PM
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03-03-2015, 04:49 PM
I think he was referring to the disc for mid range tuning, not the butterfly you might be thinking of. Here is a quote from the notable Bill Robison regarding the tuning of the "air bleed" carb on the Saito FA 120abc engine, one of which I have.:
"Adjusting the AB carb is a little different from the TN. WARNING: If the engine is running well DO NOT RESET the mid range disc adjustment. If you feel it's needed, first reset it to its base setting. ee the pictures, the line on the disc and the cast boss on the carb body give the initial position. Similar to the TN, first peak the high speed, but for the moment don't give it the few clicks rich. Next drop to 1/2 throtle, let the engine settle to a smooth run, and pinch the fuel line. The rpm should rise justn a little, and then fall. Thnis shows a good mid range mixture. If it falls immediately or doesn't rise at all, the mid range is lean. Loosen the two clamp screws on the strap holding the brass colored disc, turn it to put the line on the disc 1/32" to 1/16" below the boss on the body. It's sensitive, probably take a couple tires to get it right. Alternately, if the rpm climbs a fair bit and holds for more than 5 or 10 seconds before it falls, you're too rich. In this case reset the disc line above the boss on the body. Once you get the disc set go back to full throttle, peak the HS again,and this time do go back 200 rpm or so on the rich side of peak. Go to idle, again let the engine settle, and check the transition to full throttle. Adjust the air bleed screw as needed to get the engine to come off idle well. This is exactly like the twin needle, except in this case turn the screw IN for rich, and OUT for lean"
Sincerely, Richard
Club Saito #635; Saito 56, 100, 120abc, 130T, 180
"Adjusting the AB carb is a little different from the TN. WARNING: If the engine is running well DO NOT RESET the mid range disc adjustment. If you feel it's needed, first reset it to its base setting. ee the pictures, the line on the disc and the cast boss on the carb body give the initial position. Similar to the TN, first peak the high speed, but for the moment don't give it the few clicks rich. Next drop to 1/2 throtle, let the engine settle to a smooth run, and pinch the fuel line. The rpm should rise justn a little, and then fall. Thnis shows a good mid range mixture. If it falls immediately or doesn't rise at all, the mid range is lean. Loosen the two clamp screws on the strap holding the brass colored disc, turn it to put the line on the disc 1/32" to 1/16" below the boss on the body. It's sensitive, probably take a couple tires to get it right. Alternately, if the rpm climbs a fair bit and holds for more than 5 or 10 seconds before it falls, you're too rich. In this case reset the disc line above the boss on the body. Once you get the disc set go back to full throttle, peak the HS again,and this time do go back 200 rpm or so on the rich side of peak. Go to idle, again let the engine settle, and check the transition to full throttle. Adjust the air bleed screw as needed to get the engine to come off idle well. This is exactly like the twin needle, except in this case turn the screw IN for rich, and OUT for lean"
Sincerely, Richard
Club Saito #635; Saito 56, 100, 120abc, 130T, 180
03-03-2015, 08:04 PM
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Thanks guys. Yes, nice clean piston free of the cylinder, with a very stubborn ring. The ring gap is tiny, I have slightly enlarged it with a steel pick, but no luck yet. What I need is a way to hold the piston securely without damaging it - maybe then I can drive the end of the ring free by gently hammering the pick into it. Any thoughts on holding the piston without marring or distorting it?
03-03-2015, 08:29 PM
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Thanks Richard,
I was thinking of the disc on the Perry or late K&B carb. Looks like I was on the right track. I did a search on FA-120 ABC and found a pic of the right side of the engine. It looks like all the mixture adjustments are on that side. I'd like to see a close up of it.
I wasn't aware of the 120 ABC. My introduction to Saitos was with the FA-45 Mk2 ABC, which has a twin needle carb. I didn't use 120 & up engines until some years later.
CR
I was thinking of the disc on the Perry or late K&B carb. Looks like I was on the right track. I did a search on FA-120 ABC and found a pic of the right side of the engine. It looks like all the mixture adjustments are on that side. I'd like to see a close up of it.
I wasn't aware of the 120 ABC. My introduction to Saitos was with the FA-45 Mk2 ABC, which has a twin needle carb. I didn't use 120 & up engines until some years later.
CR
03-04-2015, 04:25 AM
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Thanks guys. Yes, nice clean piston free of the cylinder, with a very stubborn ring. The ring gap is tiny, I have slightly enlarged it with a steel pick, but no luck yet. What I need is a way to hold the piston securely without damaging it - maybe then I can drive the end of the ring free by gently hammering the pick into it. Any thoughts on holding the piston without marring or distorting it?
Last edited by SrTelemaster150; 03-04-2015 at 04:33 AM.
03-04-2015, 04:33 AM
I should have explained myself better,i assumed the piston was out and disconnected/disassembled.
03-04-2015, 08:21 AM
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03-04-2015, 09:58 PM
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Hopefully the gap is close to 90° from the wrist pin bore.. If it is, make a hardwood dowel slightly longer then the width of the piston that will fit the wrist pin hole snugly. Insert the dowel. then clamp the piston, in a vise W/copper, nylon wood, or other semi-firm faces positioning the ring gap upwards for access. Use a micro screwdriver to gently drive the ring end free..
I tried to be as gentle as possible, but this one was just STUCK.Darn it. Don't feel too bad, it wasn't actually a SAITO! But it was a very cool open rocker O.S. FS-60. The rest of it is in great shape, I will try posting to see if anyone has an old one lying around. DARN.
03-05-2015, 06:03 AM
03-05-2015, 06:11 AM
I find when rings are that seized only a few ideas worked. Holding the piston is usually necessary when trying to work two handed, but I find holding it in one while trying to free the ring is all I can figure on. Most times a ring is stuck due to old fuel or mistreatment and anything more than a small pin to force the gap open will likely break it in pieces. Worst case is corrosion as none of our normal methods will loosen that up.
If soaking in hot glycol does not free it up then you are limited to physically working the ring loose. Just like getting your vehicle out of snow or mud very slight movement will save the day. Each small flex breaks a bit more loose and once open enough I keep flushing and wetting with methanol.
Sometimes I try a heat gun and keep the methanol spray handy. Try not to heat up too much before hitting it with methanol and the different properties may do the work for you.
If soaking in hot glycol does not free it up then you are limited to physically working the ring loose. Just like getting your vehicle out of snow or mud very slight movement will save the day. Each small flex breaks a bit more loose and once open enough I keep flushing and wetting with methanol.
Sometimes I try a heat gun and keep the methanol spray handy. Try not to heat up too much before hitting it with methanol and the different properties may do the work for you.
03-05-2015, 02:50 PM
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Senior Tele, as usual you had good advice. I ended up cutting a length of steel rod that would fit through the wrist pin hole, and covered it with masking tape until it was a snug fit. Then I clamped the rod in a machinist's vise, and put o-rings around the piston to keep it from touching the vise. That held the works steady enough to work my pointed pick into the gap and tap it with a hammer. The end of the ring loosened up, but unfortunately it took the top of the ring land with it. I tried to be as gentle as possible, but this one was just STUCK.
Darn it. Don't feel too bad, it wasn't actually a SAITO! But it was a very cool open rocker O.S. FS-60. The rest of it is in great shape, I will try posting to see if anyone has an old one lying around. DARN.
I tried to be as gentle as possible, but this one was just STUCK.Darn it. Don't feel too bad, it wasn't actually a SAITO! But it was a very cool open rocker O.S. FS-60. The rest of it is in great shape, I will try posting to see if anyone has an old one lying around. DARN.
WOW! That sucker really was SHHTUCK!
03-05-2015, 05:09 PM
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I am guessing that it was severe corrosion... more than just rust. I've had experience with this in my 'day job' where you mix aluminum (piston) and steel (ring) with something to act as an electrolyte. Even water will do over a long enough time. Sometimes it can be severe enough that the metals are almost welded together... Not much that you can do about it at that point. I'm wondering if that's what happened here.....
Just my $.02.
Bob
Just my $.02.
Bob
03-05-2015, 05:28 PM
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Good luck finding an open rocker OS 60. They are greatly sort after by the old timer community(just like McCoy 60's). You might consider the SAM International website and check out the magazine for parts suppliers.
03-05-2015, 08:13 PM
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Ha ha, sorry for polluting the Saito thread, but I knew there were some good wrenches hanging around here!
Noel Jensen, who trades on ebay as "nubsdoesparts", sorted me out. I had just bought a rebuild kit from him (consisting of bearings, Bowman ring, and gaskets), and I emailed to ask about pistons - he has 'em! Amazing, this internet of ours.
So - the old O.S. will ride again, on the nose of a Kadet Senior, which will be parked next to my Kadet Seniorita, powered by HP VT-25. Come to think of it...maybe I should put a VT-49 on the Senior!
I swear, I do own Saitos - currently a 30A, 65 and my favorite, 90TS, all without homes.
Noel Jensen, who trades on ebay as "nubsdoesparts", sorted me out. I had just bought a rebuild kit from him (consisting of bearings, Bowman ring, and gaskets), and I emailed to ask about pistons - he has 'em! Amazing, this internet of ours.
So - the old O.S. will ride again, on the nose of a Kadet Senior, which will be parked next to my Kadet Seniorita, powered by HP VT-25. Come to think of it...maybe I should put a VT-49 on the Senior!
I swear, I do own Saitos - currently a 30A, 65 and my favorite, 90TS, all without homes.
03-06-2015, 12:02 AM
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Pretty sure I've seen to odd OS open rocker donk on rctrader.com - might be worth keeping an eye on the site. Some stuff gets snapped up pretty quick.
It's an Oz site, but I'm sure one of us Downunda get pick it up and ship it to wherever...
BJ
It's an Oz site, but I'm sure one of us Downunda get pick it up and ship it to wherever...
BJ
Last edited by BJ64; 03-06-2015 at 01:31 AM.
03-06-2015, 10:48 AM
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Thank you for the reply.....Maybe the answer is better info on adjusting the orginal carb than replacing it. Funny how most all engine manufacturers are known for their easy or difficult carbs. Perry carbs always solved my problematic 2 stroke engines.
03-09-2015, 08:03 AM
03-09-2015, 09:57 AM
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I added an LED headlight ring to my big bicycle yesterday. The shop door is open because I had the engine running, sitting since late October, it started on the first compression stroke, isn't fuel injection wunnerful?
03-09-2015, 12:02 PM
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I had one back in '66 and it was a reliable machine. As I remember, I traded it for a brand new Kawasaki A7 Avenger, 350cc two stroke. MUCH better speed but, it was like riding a 2x4. Currently messing about with a '99 BMW R1100RT.
Still have two Saitos ....FA80 on a H9 DVII and an FA91 that is currently waiting on me to finish the rebuild of my Intruder 90R.
RJ
Currently messing about with a '99 BMW R1100RT.Still have two Saitos ....FA80 on a H9 DVII and an FA91 that is currently waiting on me to finish the rebuild of my Intruder 90R.
RJ
03-09-2015, 08:20 PM
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What a beauty that was Hobbsy! Every heard of my first one? - A Frances Barnett with a Villers engine.
