New here and new boat owner 35hp 2 stroke

[Alaska_guy]

After cleaning the carbs again and adjusting all screws to 2 It fires up first time using choke. I then stop using choke and it will fire up at will and run now.

I did notice these small flake like things in the top carb when I cleaned it again. All the rest were fine. I wonder if the inner lining of the old fuel line was breaking down and plugging up the carbs jets.

I was able to put it in forward and reverse with the muffs on and it now seems like it has tons of power.

Here is to hoping the problem is solved.

[Alaska_guy]

OK, this is the best it has ran so far. Startup is still a little cranky.

https://youtu.be/NiSb8KXgkBA

[99yam40]

I would think that motor would have an electric choke you could hit (usually push in on key)when cold starting instead of having to manually operating it

[Alaska_guy]

OK, dropped it in the lake. Still having an issue staying idling. Will die after about a minute or so. It will fire right back up. Engine sounded nice and smooth on the lake. The power wasn't as aggressive as it used to be. Overall it's running way better. Before it had a miss and would cut out on the lake when you gave it the beans. Now it goes full tilt just fine, but just doesn't have the speed it had before. I think it's running a tad lean now when I give it the beans. Idle circuit needs to be leaned just a tad, if I use the choke it will kill it while idiling. Getting much closer now. Don't feel like it's gonna leave me stranded in the middle of the lake now.

I haven't been able to source a carb rebuild kit anywhere. Been searching for 20 minutes.

Anyone have a line on a company that might have a rebuild kit for this old of an outboard?

[99yam40]

click on the red Yamaha parts at the top of the page and find your motor for parts

[Alaska_guy]

Thanks! That also helped me confirm it was a 40hp detuned to 35hp. My jets are 70 slow and 125 main and the site shows 70 slow 130 main jet. L4 is stamped on the seats of my current ones.

[Alaska_guy]

I have all pilot screws set at 1 turns out. I initially stated 2 turns out. I forgot I was counting half revolutions when I was documenting. I had to check my notes.

Long story short I misrepresented how many turns out the pilot screws were set at.

I found this post while searching... I plan to set them according to username: boats.net. interesting how the middle carb is drastically different from the others.

https://www.yamahaoutboardparts.com/...bs-adjustments

[99yam40]

Thanks! That also helped me confirm it was a 40hp detuned to 35hp. My jets are 70 slow and 125 main and the site shows 70 slow 130 main jet. L4 is stamped on the seats of my current ones.

I asked early on what made you think this was a 35 and you never answered that question.

following advice on a 30 hp motor while working on your 40 does not make sense to me.
how was your 40 detuned to a 35 and how do you know it was?

[Alaska_guy]

My uncle stated he paid a marine shop to have the 40 detuned to a 35hp. I called him last night and he told me so and gave me the name of the shop. There is a river here that requires less then 40hp engines and that's the only river he fished. So to meet regs for that river he had to have it detuned. It was done by deweys cook inlet Inc. That same river now no longer allows 2 stroke engines any longer so there is no reason to keep it "detuned".

Thanks for the advice. I will keep the pilot screws at 1 turn out for now then. It at least idles and runs enough to get me into gear and once I get on the throttle it's fine..

I cleaned the carbs, checked all needles and seats. Removed the main and low speed jets and cleaned them, including the side holes of the jets.

[99yam40]

My uncle stated he paid a marine shop to have the 40 detuned to a 35hp. I called him last night and he told me so and gave me the name of the shop. There is a river here that requires less then 40hp engines and that's the only river he fished. So to meet regs for that river he had to have it detuned. It was done by deweys cook inlet Inc. That same river now no longer allows 2 stroke engines any longer so there is no reason to keep it "detuned".

Thanks for the advice. I will keep the pilot screws at 1 turn out for now then. It at least idles and runs enough to get me into gear and once I get on the throttle it's fine..

I cleaned the carbs, checked all needles and seats. Removed the main and low speed jets and cleaned them, including the side holes of the jets.

I would be contacting the shop to see what they did to detune the motor to see what needs to be changed back correctly.
ask them what the settings should be since you do not have a manual

[Alaska_guy]

Thanks. Apparently it's a shifter linkage kit. It was a very popular thing back in the early 2000's.

https://forums.iboats.com/threads/re...etuned.325839/

https://forums.outdoorsdirectory.com/forum/alaska-boating-forums/alaska-power-boating/57949-need-help-with-a-detune-kit

[99yam40]

well that said it was the cam on the throttle not opening the throttle plates completely.
so you need to find out if that is true on the Yamaha you have also.
and ask them if they still have one of the original for you to put back on

you still need to find the proper settings for the pilot screws
and follow the procedure for syncing the carbs together with the throttle plates all completely closed, not just in the idle position

[Alaska_guy]

Thanks. I checked the needle and seats and they looked good. It's running much better. I purchased a hardline hour/tach gauge to help me dial in the idle rpms, plus now I can see how many rpms I am turning at full throttle. Just need to get it in the water to test.

[Alaska_guy]

Still fighting the issue. Upped the idle and that keeps it running but it's not right. I can feel it wanting to thunk into gear a little. I revved it today in the lake while idiling, manually by pushing down on the idle rod. After revving a few times blue smoke went everywhere. I wonder if the auto oiler is messed up and just fouling the plugs. I need to see how to go about removing the auto oiler and mix my own fuel.

[Alaska_guy]

OK, removed the oiler and premixed fuel. She fires up everytime now on muffs. Surely helped. I think the on board oiler was fouling plugs at idle. It still has a small miss at idle, but so fsr it idles 50% better. Will try again Sunday to get it in the water. I sprayed carb cleaner around all gaskets and no leaks.