Oil Injection Removal -Yamaha 50hp - 2 Stroke - 3 Cylinder

[Turpentine]

I appreciate the answer. I could only assume that with Jeff doing the head and block work and knowing what pistons were going to be used that that part was done correctly. He did skim the head a little as well. I'm well within 10% of each other with the readings so I'm not worried about it I was just curious as to what the drop might be as both of my motors show about the same difference. All the holes were matched at 20 over on the newer motor. Both crank easily and idle great. They both run very smooth through the rpm range. I did add CCM sport reeds to both as I really like what they do for the idle in particular. The older motors compression is 105-105-96. I just use it as a spare. I'll likely rebuild it in the near future as there is a definite difference in the two coming out of the hole and thru the midrange. Which is where I need it. I'm not really looking for all out speed. I have not done any back to back type tests with oil shaft in place vs out. The only other thing I can think of is that I'm only about 3/4 of the way through breakin and have just backed off of double oil. I have taken my time and been pretty gentle through breakin. I've only taken it up to WOT 3 times now and each time for less than 30 seconds. I've burned almost 10 gallons of gas thru it now. I've done several heat cycles with it so far. Varying RPMs quite a bit. My numbers might settle in a little bit more as the rings continue to seat. Again I really appreciate you responding. I appreciate any advice you may have.

[Gone South]

Another variance is everyone’s own method of installing carbs. Proper way is back the set screw off so all 3 butterflies fully close. Snug the carb with the set screw down first then snug the other two while making sure there is not any throttle linkage force acting on the butterflies. If you haven’t been doing this, look into carburetor link n sync. When idling you want to verify all 3 pull equal vacuum through the venturi.

[Turpentine]

Again I appreciate your response. I apologize if I'm long winded and full of questions.
Yes sir the first thing I did before I started this build was buy the shop manual for my particular motor. I went through the link and sync and made sure everything was good there. I've also been checking spark plug color and that looks good. I do have one more question regarding set up and adjustment. My manual for my 86 motor went through the process of setting the timing with a timing light and explained adjusting the linkage to set timing. This new manual for the 2006 model only lays out the process of adjusting stops and linkages to allow the linkage arrow to point at the corresponding marks on the cdi box for idle position and WOT. There is no mention anywhere in the manual of checking timing with a timing light and corresponding marks on the flywheel. Is it necesary to check timing with a light on the newer motors with the new style CDI box and marks? I could do it. Just wondering if it's necessary to do it. Particularly with the motor running as well as it is

[ecu1984]

Another variance is everyone’s own method of installing carbs. Proper way is back the set screw off so all 3 butterflies fully close. Snug the carb with the set screw down first then snug the other two while making sure there is not any throttle linkage force acting on the butterflies. If you haven’t been doing this, look into carburetor link n sync. When idling you want to verify all 3 pull equal vacuum through the venturi.

The above is real important, I also balance mine with a vacuum gauge set-up, just like motorcycle shops use to tune bikes.
I use a Carbtune Pro 4. One of the best "specialty tools" I have ever purchased. Have used it to smooth out many engines
others couldn't get to idle right,

[Turpentine]

Thank you for that information. I'll take a look at one of those. It took me a while to get my 86 model to idle right. Timing was off and carbs were way out of adjustment. It runs like a sewing machine now other than being a bit "tired".
I did the link and sync on the 2006 when I rebuilt it. Just got it all back together at Thanksgiving. It runs and idles like a brand new motor. Cranks right up also. Never had one with the Prime Start but so far it's been nice.

I'm more of a farm mechanic vs outboards. That's the reason for all the questions. That and the Yamaha manual I bought leaves a lot to be desired.

[ecu1984]

If you are anywhere near Irmo/Columbia, you can borrow my vacuum tuner whenever.
It's super easy to use

[FEETDOWN]

I love the way 2 strokes sound and smell. What I love even more is how my 4 stroke magically and immediately starts purring when I bump the key. I alllllmost sold it and bought a 2 stroke before duck season. So glad I got talked out of it

[Tater]

You’re too old to go back to a real motor.

[Turpentine]

With my boat and my big rear end im at a pretty big disadvantage with my particular boat when it comes to power to weight ratio or I might entertain a four stroke. Put a dog, decoys, and a couple more people in it with me and a 25 or 35 don't get it done. Ive had both. The 50 2 stroke is just about right. Fact is I love the 2 strokes also and run them "because I can". I don't take it well when the government tries to dictate what I run or don't run. They can choke on my smoke a little while longer before I switch anything or go to the grave. If that happens and the 2 stroke is still on there I'll consider it a small victory.

[FEETDOWN]

You’re too old to go back to a real motor.

Ain't no part a lie

[ecu1984]

I discovered fuel injection years ago and hope to never "soak' and rebuild another carb
unless of course its on a 65 Vette or such

[Turpentine]

I discovered fuel injection years ago and hope to never "soak' and rebuild another carb
unless of course its on a 65 Vette or such

This just reminded me how much it sucks sometimes to live on my side of the tracks. But it can be pretty cool too. Hell everything I have is old and needs work. That includes me. I wouldn't know what to do with new stuff. My newest motor is 18 years old but freshly rebuilt, by me. It's on a 27 year old War Eagle. My flats boat is all 1996 vintage and built like a tank with a 115 Johnson on it that runs pretty doggone good. My 1986 50 yahama is older than most of the people I pass on the way to the duck blind and I'm a lot older than it is. If I didn't have to work on something I wouldn't feel right.

[Turpentine]

I do appreciate the offer. I'm about an hour and a half southeast of you but I do get through there now and again.

[ecu1984]

This just reminded me how much it sucks sometimes to live on my side of the tracks. But it can be pretty cool too. Hell everything I have is old and needs work. That includes me. I wouldn't know what to do with new stuff. My newest motor is 18 years old but freshly rebuilt, by me. It's on a 27 year old War Eagle. My flats boat is all 1996 vintage and built like a tank with a 115 Johnson on it that runs pretty doggone good. My 1986 50 yahama is older than most of the people I pass on the way to the duck blind and I'm a lot older than it is. If I didn't have to work on something I wouldn't feel right.

when you get a good dependable two-stroke and maintain it.................nothing better in my book