Welcome to Club SAITO !
01-20-2022, 06:02 AM
"Claude" moved up to my house from Brian's a couple months ago He is happy here in the country. Been working up loads for my 300 blackout. The pilot has been worried with all the shootin round here.
01-21-2022, 09:16 AM
Saito 125
I had a “squirrel!” moment and decided I need a Saito 125 for a future build. So I bought one used and of course that’s always a gamble. The engine itself looks good, is smooth with massive compression but I now think it’s been rebuilt. I asked the previous owner about this, he claims it has not and is now getting defensive about it. The drive hub has puller marks on it and the carb looks messed with. So now I have to go through it and make sure everything is how it should be.
So my questions are 1) the hs needle valve looks brand new so does it look like the correct one? 2) should there be a spring in this carb? The throttle barrel has a little play and the retaining bolt shows wear on the end. 3) the cat eye on the spray bar is oriented towards the air intake, not the intake tube. Is this correct?
Thanks guys!
So my questions are 1) the hs needle valve looks brand new so does it look like the correct one? 2) should there be a spring in this carb? The throttle barrel has a little play and the retaining bolt shows wear on the end. 3) the cat eye on the spray bar is oriented towards the air intake, not the intake tube. Is this correct?
Thanks guys!
01-21-2022, 09:55 AM
Why not just run it?
Did you pull the rear cover and simply look inside!
Rusty or dirty ?
The scarred prop hub is pretty common but not proof positive that it was rebuilt. The carb on the 125 iirc is one model Saito that did not use the spring. Why tear down with good compression and only peripheral questionables?
Did you pull the rear cover and simply look inside!
Rusty or dirty ?
The scarred prop hub is pretty common but not proof positive that it was rebuilt. The carb on the 125 iirc is one model Saito that did not use the spring. Why tear down with good compression and only peripheral questionables?
01-21-2022, 10:03 AM
Why not just run it?
Did you pull the rear cover and simply look inside!
Rusty or dirty ?
The scarred prop hub is pretty common but not proof positive that it was rebuilt. The carb on the 125 iirc is one model Saito that did not use the spring. Why tear down with good compression and only peripheral questionables?
Did you pull the rear cover and simply look inside!
Rusty or dirty ?
The scarred prop hub is pretty common but not proof positive that it was rebuilt. The carb on the 125 iirc is one model Saito that did not use the spring. Why tear down with good compression and only peripheral questionables?
01-21-2022, 12:30 PM
I agree, I won’t tear it down needlessly. It was -7 this morning so no test run.
The bearings look original and it well oiled. You can see the marks on the hub. The carb was clearly taken apart for some reason which makes me wonder why. I installed a new spring keeper nut and intake-cylinder o-ring & washer and put her all back together. Now I’ll check valve clearances and wait for a warmer day for a run.
The bearings look original and it well oiled. You can see the marks on the hub. The carb was clearly taken apart for some reason which makes me wonder why. I installed a new spring keeper nut and intake-cylinder o-ring & washer and put her all back together. Now I’ll check valve clearances and wait for a warmer day for a run.
01-21-2022, 01:16 PM
One more time
There was one version of that carb, either the 100, 115 or 125 that used no spring. I don't recall now which one.
Better check before adding one.
Good luck with the run.
There was one version of that carb, either the 100, 115 or 125 that used no spring. I don't recall now which one.
Better check before adding one.
Good luck with the run.
01-21-2022, 02:19 PM
I had a “squirrel!” moment and decided I need a Saito 125 for a future build. So I bought one used and of course that’s always a gamble. The engine itself looks good, is smooth with massive compression but I now think it’s been rebuilt. I asked the previous owner about this, he claims it has not and is now getting defensive about it. The drive hub has puller marks on it and the carb looks messed with. So now I have to go through it and make sure everything is how it should be.
So my questions are 1) the hs needle valve looks brand new so does it look like the correct one? 2) should there be a spring in this carb? The throttle barrel has a little play and the retaining bolt shows wear on the end. 3) the cat eye on the spray bar is oriented towards the air intake, not the intake tube. Is this correct?
Thanks guys!
So my questions are 1) the hs needle valve looks brand new so does it look like the correct one? 2) should there be a spring in this carb? The throttle barrel has a little play and the retaining bolt shows wear on the end. 3) the cat eye on the spray bar is oriented towards the air intake, not the intake tube. Is this correct?
Thanks guys!
The hsn fits everything from FA-45S through FA-125, no problem there.
The cateye should face towards the intake tube (manifold). Downstream side.
The prop hub appears to have been pulled. Crank may have been bent in a crash along with damage to the original carb body.
Check your valve timing (visually) without disassembling the engine.
The carb should have a barrel spring, mine does anyway.
Overall, the engine appears to be a low time unit.
ETA: Good call on replacing the intake tube oring, that one was improperly installed. Probably leaked like a sieve. Very likely why the "poor running" engine was sold.
Last edited by Glowgeek; 01-21-2022 at 02:28 PM.
01-21-2022, 03:32 PM
Hard to see detail on the little phone screen.
Good deal on the spring. Was not recalling which one was spring free. Likely the 115.
Maybe Dave can check his 100 (?)
Pretty easy to do a rudimentary prop tip runout check on the crank.
Good deal on the spring. Was not recalling which one was spring free. Likely the 115.
Maybe Dave can check his 100 (?)
Pretty easy to do a rudimentary prop tip runout check on the crank.
Last edited by Jesse Open; 01-21-2022 at 03:35 PM.
01-21-2022, 06:40 PM
My Feedback: (1)
Saito 125.
boy, if it has been run why is the Exhaust Port so super clean !
I agree about the carb's Barrel and tiny screw, they look too warn to be brand new.
maybe it was run a bit and it crashed and it now has a brand new cylinder on it ??
Jim
boy, if it has been run why is the Exhaust Port so super clean !
I agree about the carb's Barrel and tiny screw, they look too warn to be brand new.
maybe it was run a bit and it crashed and it now has a brand new cylinder on it ??
Jim
Last edited by the Wasp; 01-21-2022 at 06:47 PM.
01-21-2022, 06:59 PM
Good news! Crankshaft & drive hub are straight. You guys had me worried for a while. Below is my rudimentary run out gauge.
Maybe an attempt was made to remove the hub? Who knows. I think the bearings are original and they’re smooth. I’ll flush it with some raw fuel, dry it, re-oil and call it good.
I think perhaps there was a crash and the original spray bar assembly & needle valve were damaged. That would explain why the needle valve looks brand new and the spray bar was just assembled wrong. So I need to order a carb screw/spring kit from Horizon, reassemble the carb properly and this engine should be as good as new.
Maybe an attempt was made to remove the hub? Who knows. I think the bearings are original and they’re smooth. I’ll flush it with some raw fuel, dry it, re-oil and call it good.
I think perhaps there was a crash and the original spray bar assembly & needle valve were damaged. That would explain why the needle valve looks brand new and the spray bar was just assembled wrong. So I need to order a carb screw/spring kit from Horizon, reassemble the carb properly and this engine should be as good as new.
01-22-2022, 03:53 AM
Senior Member
Quick, the spraybar is nearly upside down, the "catseye" needs to point straight up the center of the intake pipe. Place the HS needle on the spraybar when you push the spray out, then push the spraybar back in, don't pull it in with the nut that holds the clip.
Wrong way.
Correct way.
Wrong way.
Correct way.
01-22-2022, 07:38 AM
Thanks Sportster. That’ll be the next trick. To reposition the spray bar without damaging anything. I think a little heat on the carb body should help in pressing the spray bar out. Good tip on using the needle valve.
Didn't realize there was a B version of this engine. Looks like the cooling fin area has been improved a bit.
Didn't realize there was a B version of this engine. Looks like the cooling fin area has been improved a bit.
01-22-2022, 04:44 PM
Senior Member
Quick, I'm going to make you a properly sized velocity stack, it will take a few days as I'm out of 10mm OD K&S tubing. Your carb barrel has the relief cut in it for the spring, the springless one is flat on the end.
Last edited by 1200SportsterRider; 01-22-2022 at 05:05 PM.
01-22-2022, 07:55 PM
Wow! Thank you Sportster! That would be fantastic. Less mess and more efficient I believe.
I was at my LHS today to see what they had for me in the parts bin and I came home with a carb screw & spring set for a 200T. It has the spring, barrel retaining bolt & washer and mounting screws I’m looking for. There is a recess at the end of the throttle barrel for a spring. The owner said the spring is pretty important. It keeps the throttle barrel from vibrating which tends to shear the retaining bolt over time.
Taking things apart is easy. Putting the spray bar back in tricky. I’m thinking of using the throttle barrel to press it back in after heating the carb body.
I was at my LHS today to see what they had for me in the parts bin and I came home with a carb screw & spring set for a 200T. It has the spring, barrel retaining bolt & washer and mounting screws I’m looking for. There is a recess at the end of the throttle barrel for a spring. The owner said the spring is pretty important. It keeps the throttle barrel from vibrating which tends to shear the retaining bolt over time.
Taking things apart is easy. Putting the spray bar back in tricky. I’m thinking of using the throttle barrel to press it back in after heating the carb body.
01-22-2022, 09:12 PM
New problem. It’s all put back together but with the spring the throttle barrel won’t close all the way. Without the spring it will close all the way. Pretty certain the spray bar is in as far as it’ll go.
01-23-2022, 05:08 AM
Me too.
I recall coming across one model long ago without the spring. Thinking it had been left out by mistake I tried one . It flat out would not allow full throttle closure. After looking into the matter found it was not used from the factory in that case.I found other people who ran into the same issue at the time.
If the throttle wont close, good chance there should be no spring.
Not sure about the spot faced throttle barrel as there is a distinct possibilty the carb body on a spring free version is different as well. Saito is not so good about documenting the odd production variations.
If it comes down to it, I probably still have a few new carbs as I have been converting FG models to methanol fuel. Right now that box of parts is with a friend in North Carolina who is converting a pair of FG-20 to methanol fuel.
Anyhow I can probably help out with a factory fresh 125 carb as I bought several of them.
I recall coming across one model long ago without the spring. Thinking it had been left out by mistake I tried one . It flat out would not allow full throttle closure. After looking into the matter found it was not used from the factory in that case.I found other people who ran into the same issue at the time.
If the throttle wont close, good chance there should be no spring.
Not sure about the spot faced throttle barrel as there is a distinct possibilty the carb body on a spring free version is different as well. Saito is not so good about documenting the odd production variations.
If it comes down to it, I probably still have a few new carbs as I have been converting FG models to methanol fuel. Right now that box of parts is with a friend in North Carolina who is converting a pair of FG-20 to methanol fuel.
Anyhow I can probably help out with a factory fresh 125 carb as I bought several of them.
Last edited by Jesse Open; 01-23-2022 at 05:22 AM.
01-23-2022, 05:59 AM
Jesse, I think you may be right in that this carb has no spring. I’ll have to call Horizon Hobby tech support and see what they have to say. At the very least the cat eye is pointing in the right direction and the new barrel retaining bolt took up most of side to side wiggle in the throttle barrel. Really appreciate the offer on a new carb. Let’s see what happens with this one first.