# Cayo 30 2 stroke



## RunningOnEmpty (Jun 20, 2015)

What motor? The powertech SRA3 props are good. The heavy cupping and rake make them perform like a higher pitch. My Yamaha stainless 13p prop has a better holeshot and top speed vs my SRA3 13P. I should have bought a 12P SRA3.


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## Troutset (Aug 23, 2015)

RunningOnEmpty said:


> What motor? The powertech SRA3 props are good. The heavy cupping and rake make them perform like a higher pitch. My Yamaha stainless 13p prop has a better holeshot and top speed vs my SRA3 13P. I should have bought a 12P SRA3.


Yamaha 30 2 stroke. Thinking of 11P 3 blade with extra cup.


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## RunningOnEmpty (Jun 20, 2015)

2 cylinder or 3? I have the 3 cylinder and Yamaha claims that the motor makes it's max rated HP @ 5000 rpms. Max recommended is 5500 rpms. I run mine well over the max rated rpm when solo. My motor has been modified and the powerband has been moved up from exhaust and intake mods.


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## Troutset (Aug 23, 2015)

RunningOnEmpty said:


> 2 cylinder or 3? I have the 3 cylinder and Yamaha claims that the motor makes it's max rated HP @ 5000 rpms. Max recommended is 5500 rpms. I run mine well over the max rated rpm when solo. My motor has been modified and the powerband has been moved up from exhaust and intake mods.


3 cylinder 30. How does the mods affect reliability of the motor. I was looking at the hyro tec kit to bump it up a bit.


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## RunningOnEmpty (Jun 20, 2015)

I have been talking to others that run their little 3 cylinders beyond what the Hydro tec kit allows and they don't have any issues. It can't be good though! I just bought one of the last few things needed to complete mine. I'm fitting the Tohatsu 40hp carbs very soon . The high compression head from Hydro tec is next. Not looking forward to removing the stock head!


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## No Bait / Lures Only (Apr 10, 2011)

RunningOnEmpty said:


> I have been talking to others that run their little 3 cylinders beyond what the Hydro tec kit allows and they don't have any issues. It can't be good though! I just bought one of the last few things needed to complete mine. I'm fitting the Tohatsu 40hp carbs very soon . The high compression head from Hydro tec is next. Not looking forward to removing the stock head!


With the head modification, be prepared to run 91-93 octane to capture the head upgrade performance........


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## RunningOnEmpty (Jun 20, 2015)

stephenchurch said:


> With the head modification, be prepared to run 91-93 octane to capture the head upgrade performance........


87 would pre detonate and burn up the pistons more than likely.


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## No Bait / Lures Only (Apr 10, 2011)

RunningOnEmpty said:


> 87 would pre detonate and burn up the pistons more than likely.


That is the gas grade I have been running in 90 and 25 modded motors since 1990 with no issues at all....


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## RunningOnEmpty (Jun 20, 2015)

stephenchurch said:


> That is the gas grade I have been running in 90 and 25 modded motors since 1990 with no issues at all....


How much compression does your 25hp have?


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## No Bait / Lures Only (Apr 10, 2011)

RunningOnEmpty said:


> How much compression does your 25hp have?


Call Jon Wolfe @ Hydrotec for specifications, the head is cut by them and octane recommendations as well....


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## RunningOnEmpty (Jun 20, 2015)

If I remember correctly they recommend a minimum of 91 octane with a shaved head.


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## No Bait / Lures Only (Apr 10, 2011)

RunningOnEmpty said:


> If I remember correctly they recommend a minimum of 91 octane with a shaved head.


Empty, how did the completed motor run? Please advise the details.....thanks in advance........


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## RunningOnEmpty (Jun 20, 2015)

I have been trying different main jets and now my plugs are a perfect light tan color. I had to use bigger 125 main jets from a Yamaha 25hp 2 cylinder. Turns out my Tohatsu 40hp carbs are the same as the newer Yamaha 25hp 2 cylinder 2 stroke. I need some different props for more testing. I'm not sure if I need to go up or down in pitch? The good news is it's running really good and I can go fishing again. The motor probably runs 5/6 mph faster vs stock now. I didn't spend a lot of money doing this. Maybe $250 so far? I found someone that makes a custom CNC hemi head and I'm still waiting for a response on pricing. Hydo Tec is only offering a shaved down factory head. I could do my own at my shop for the cost of a new head gasket.


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## No Bait / Lures Only (Apr 10, 2011)

RunningOnEmpty said:


> I have been trying different main jets and now my plugs are a perfect light tan color. I had to use bigger 125 main jets from a Yamaha 25hp 2 cylinder. Turns out my Tohatsu 40hp carbs are the same as the newer Yamaha 25hp 2 cylinder 2 stroke. I need some different props for more testing. I'm not sure if I need to go up or down in pitch? The good news is it's running really good and I can go fishing again. The motor probably runs 5/6 mph faster vs stock now. I didn't spend a lot of money doing this. Maybe $250 so far? I found someone that makes a custom CNC hemi head and I'm still waiting for a response on pricing. Hydo Tec is only offering a shaved down factory head. I could do my own at my shop for the cost of a new head gasket.


Hemi Head ? Won't you have to change the pistons to take advantage of that shape difference? What is your top speed/rpm, I have 3 different props and they all act differently.
powertec 12 sra 32/33 5800/5900
turbo hot shot 12 33/35 6850
solias 13 29/30 5200
best luck........


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## No Bait / Lures Only (Apr 10, 2011)

stephenchurch said:


> Hemi Head ? Won't you have to change the pistons to take advantage of that shape difference? What is your top speed/rpm, I have 3 different props and they all act differently.
> powertec 12 sra 32/33 5800/5900
> turbo hot shot 12 33/35 6850
> solias 13 29/30 5200
> best luck........


Just remembered, my 2 cyl 25 2 stroke carbs were venturi's opened up and rejetted at hydrotec, they are 2006 model carbs....


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