YS-63 Engine Rebuild
#1
Senior Member
Thread Starter
My Feedback: (7)
Join Date: Oct 2003
Location: Round Rock,
TX
Posts: 2,024
Likes: 0
Received 0 Likes
on
0 Posts
YS-63 Engine Rebuild
Ok, I have an YS63-FZ original model. It is now about 6-7 years old and has seen about 30-40 gallons of fuel would be my approximation. It use to run great but started acting up last year. I replaced the diaghram and checked the valves. The valves looked fine other than some mild rust. The diaghram was pretty worn. Anyway, it ran "ok" not great for another 6 months but this last weekend, it kind of finished up. I adjusted the regulator because at 3500 RPM, it was slowly loosing RPM. I turned the regulator in alot and it was still doing it. It finally got to the point where it stopped and it starting surging on full throttle to the point that it sounded like it was running way too fast and then stopped. I let it cool, tried to restart it and it started up but I couldn't advance the throttle without the motor wanting to die. I kept trying and then it died. I repeated the process again-same thing. Then I tried it one more time and the motor would not start at all.
I really think its time just to rebuild the motor and go through it part by part. Its really had a lot of run time. I'm interested in the "consumables" I'm going to need to pre-order. First, I am worried about the compression. Running forward, the motor feels like its got no compression at all. But, I know the YS turns a lot of the forward motion compression into the fuel system. When I run the motor backwards, it feel like its got very good compression. I can feel and hear air coming out of the carb. and if I hold my hand over the muffler, it will form a good vacuum. It seems like the engine never had much compression going forward.
So my first question is.
1. Do I need a new ring?
What other consumables am I going to need?
1. Valve gasket (I know this is leaking from the time I checked the valves. Also some of the valve parts were a tiny bit rusty when I adjusted them 6 months ago. I removed as much rust as I could without taking it apart but taking everything apart will allow me to remove any additional rust.
2. Is there a gasket kit?
3. O'ring kit?
4. I think the bearings feel fine....at least the front one for sure. I don't feel any "sandy" feeling and the compression and engine turning over is smooth.
5. The diaphram is fairly new. Should I replace the spring or the plunger? The plunger looks like it could use some cleaning with fine emery cloth.
6. Are there any other parts that are typical for replacement at this mileage like in the fuel/carb area? What about the disc valve...does this part wear out?
Thanks in advance.
I really think its time just to rebuild the motor and go through it part by part. Its really had a lot of run time. I'm interested in the "consumables" I'm going to need to pre-order. First, I am worried about the compression. Running forward, the motor feels like its got no compression at all. But, I know the YS turns a lot of the forward motion compression into the fuel system. When I run the motor backwards, it feel like its got very good compression. I can feel and hear air coming out of the carb. and if I hold my hand over the muffler, it will form a good vacuum. It seems like the engine never had much compression going forward.
So my first question is.
1. Do I need a new ring?
What other consumables am I going to need?
1. Valve gasket (I know this is leaking from the time I checked the valves. Also some of the valve parts were a tiny bit rusty when I adjusted them 6 months ago. I removed as much rust as I could without taking it apart but taking everything apart will allow me to remove any additional rust.
2. Is there a gasket kit?
3. O'ring kit?
4. I think the bearings feel fine....at least the front one for sure. I don't feel any "sandy" feeling and the compression and engine turning over is smooth.
5. The diaphram is fairly new. Should I replace the spring or the plunger? The plunger looks like it could use some cleaning with fine emery cloth.
6. Are there any other parts that are typical for replacement at this mileage like in the fuel/carb area? What about the disc valve...does this part wear out?
Thanks in advance.
#2
Senior Member
My Feedback: (2)
Join Date: Jul 2005
Location: La Pine,
OR
Posts: 672
Likes: 0
Received 0 Likes
on
0 Posts
RE: YS-63 Engine Rebuild
I'd give YS parts & Service a call and talk with them about your engine. Then, based on their advice, you could order up the parts you need right then and there. I have always found them very helpful. They're nice guys too.
Paul
YS Parts and Service
1370 Porter Drive
Minden, Nevada 89423
Phone : (775) 267-9252
Paul
YS Parts and Service
1370 Porter Drive
Minden, Nevada 89423
Phone : (775) 267-9252
#3
Senior Member
My Feedback: (12)
Join Date: Dec 2001
Location: Port of Spain, FL
Posts: 619
Likes: 0
Received 0 Likes
on
0 Posts
RE: YS-63 Engine Rebuild
you might want to gas port the piston, all newer YS engines have this
its done by drilling 4 holes on the top of the piston to just behind the ring
helps with the compression
if doing it yourself make sure you know what you are doing
its done by drilling 4 holes on the top of the piston to just behind the ring
helps with the compression
if doing it yourself make sure you know what you are doing
#4
Senior Member
Thread Starter
My Feedback: (7)
Join Date: Oct 2003
Location: Round Rock,
TX
Posts: 2,024
Likes: 0
Received 0 Likes
on
0 Posts
RE: YS-63 Engine Rebuild
ORIGINAL: lennyk
you might want to gas port the piston, all newer YS engines have this
its done by drilling 4 holes on the top of the piston to just behind the ring
helps with the compression
if doing it yourself make sure you know what you are doing
you might want to gas port the piston, all newer YS engines have this
its done by drilling 4 holes on the top of the piston to just behind the ring
helps with the compression
if doing it yourself make sure you know what you are doing
#5
RE: YS-63 Engine Rebuild
Yes, If life has been good, and no repeated symtoms of RPM surging (ring seating problems) you won't need the gass porting.
My experiences with these engines is that they absolutely benefit from a full strip down, replace everything service.
Ring, bearing, gaskets O rings, valves etc.
If it isn't an obvious problem/fix don't hesitate... just send it in for the full service. It costs some... but you'll get a Brand New engine back.
I try and do it every year. Well worth it.
My experiences with these engines is that they absolutely benefit from a full strip down, replace everything service.
Ring, bearing, gaskets O rings, valves etc.
If it isn't an obvious problem/fix don't hesitate... just send it in for the full service. It costs some... but you'll get a Brand New engine back.
I try and do it every year. Well worth it.
#6
Senior Member
Thread Starter
My Feedback: (7)
Join Date: Oct 2003
Location: Round Rock,
TX
Posts: 2,024
Likes: 0
Received 0 Likes
on
0 Posts
RE: YS-63 Engine Rebuild
Just not sure about the Piston Ring...
Not even sure exactly how I can tell if it needs a new one when I look at it.
Overhauls have worked very well before me. All kinds of hidden girt and grime, rust, corrosion and other things get uncovered and cleaned up which just happen from lots of use and time.
Not even sure exactly how I can tell if it needs a new one when I look at it.
Overhauls have worked very well before me. All kinds of hidden girt and grime, rust, corrosion and other things get uncovered and cleaned up which just happen from lots of use and time.
#7
Senior Member
Join Date: Oct 2002
Location: Malaysia, MALAYSIA
Posts: 990
Likes: 0
Received 0 Likes
on
0 Posts
RE: YS-63 Engine Rebuild
How much it cost to overhaul it like mentioned by YS, I mean send them in and get it done by YS Team?
Any idea how much would be for the YS110?
Any idea how much would be for the YS110?
#9
My Feedback: (58)
RE: YS-63 Engine Rebuild
Richard and the crew at YS Parts & Service will get your engine back in tip top shape. I had a 1.40L that was giving me fits and they got it back to normal. I was going to put a new ring, piston and liner in it but they changed out a few gaskets, the plunger spring and the bearings and all was better. It saved me a few bucks and a few gray hairs.
Give them a call.
Give them a call.