I'm sure someone knows how to work those heads. It would be a fun project to play with.
Type: Posts; User: Tiller guy; Keyword(s):
I'm sure someone knows how to work those heads. It would be a fun project to play with.
I read somewhere that those motors can't handle high rpm's because of valve float. Fact or BS?
My old yamaha 30hp had a misty vapor coming out of the carb bores at high speeds until I installed Chris Carson race reeds with reed blocks from the yamaha 40/50 hp. ...
Did you use lock tite? I'm always worried the screws will come out and go through the motor.
I was researching the merc inline 3 cylinders and found info suggesting they have valve float beyond the factory recommended rpm's.
Sooner or later everyone will be running a 4 stroke and people will be doing custom head work and intake mods. A 450cc 4 stroke dirt bike produces around 50hp. That tohatsu 30hp is over 500cc.
Actually my new 4 stroke motor is 20 lbs lighter than a comparable E-tec and both are slow when compared against my old yamaha. There isn't anything on the market today that's worth getting excited...
RPM'S? No tach because it's a tiller motor and the prop has a pressed rubber hub. The noise goes away at speed, but wow it's awful at low speed.
Suzuki. I figured it was a 4 stroke issue even though my dealer disagrees.
The new prop chatters out of the water as well while at a very low idle in gear on the muffs. I have been told it's the clutch dog? There's no metal in the gear lube and it shifts perfect. I think...
I hit something at wot and it stopped the motor really fast. The roll pin that holds the crank bearing sheared off and then it went into the #2 cylinder. I loved the motor and it hauled ***, but I...
Flats fishermen down here in FL will pay the high prices. 99% of them have no interest in doing mods.
I sold my 1995 Yamaha 30hp for $800 blown up and the insurance company paid out $2600 on top of it. They are worth a lot to the right buyer.
My new motor sounds like it's gonna come apart at low rpm with the new stainless prop. Everything seemed fine with the stock aluminum prop that came with the new motor. The dealer said it's normal...
I learned this the hard way. It was fun while it lasted.
Your gonna need some big jets!
I was reading that some of the high performance oils will cause plug fouling in low temp motors. My motor almost runs too clean now if that's even possible?
If I run my outboard WOT 90% of the time would the Quicksilver Full Synthetic 2-Stroke PWC Oil be safe? Someone gave me 2 gallons of it for free.
All of the throttle shafts should interchange. I just went through this with my little Yamaha.
I ran the 122 jets and the motor ran great, but I lost 1 mph. So I re installed the 125's and my idle mixture was off again. I thought it was running great on the hose so I went out for another test...
Did you shave the head? I'm running 40 carbs with CCMS race reeds, cut down tuner and 40/50 reed cages. I'm a little nervous about removing the head because it's a saltwater motor.
I did my first test run and so far a 3 mph gain. Motor felt rough when gently accelerating, but it ran strong when I hit the throttle hard. More torque for sure and the 125 jets might be a little too...
These look very nice http://www.boatracingfacts.com/forums/showthread.php?9988-Yamaha-30-Head-Project
I found the 125 jets for you grayson http://www.boats.net/parts/search/Yamaha/Outboard/2006%20and%20Later/25MSH/CARBURETOR/parts.html. The newer Yamaha 25hp 2 cylinder twin carb uses the same Teikei...
I'm finally ready to buy one because I'm always cleaning small carbs. How much power and what's the best cleaner? This is the one I'm looking at now...
My local outboard shops don't know anything about the jets. One guy told me that my motor will never run right again LOL
My carbs came off of a Nissan NS40D. Same as Tohatsu. The fuel pump on the bottom doesn't work because of the shifter rod being in the way. ...
The Yamaha 30hp butterfly shaft is a perfect fit. My carbs have 125 jets. I thought 122 was the norm?...
Nice to see that the stock throttle link rod works. Good luck on testing! Keep us posted.
Any test results yet? I remember someone saying the stock yamaha link rod worked ok?
I take it your motor is premix? The oil injected motors have a linkage arm on the other side of the carbs that controls the oil pump.
What about the auto lube linkage?
Restriction on prop spacer? What prop are you running?
Grayson, Thanks for the comparison! I have the 40hp blocks and the race reeds ready. I was expecting the reed blocks to be the same, but I was wrong. I'm still debating the high compression head?
Did you buy the racing or sport CCR reeds? How did you open up your stops? Johnson used shims on the little 15hp motors. I thought about trying that on my 30hp.
Vise grips and lots of heat around the bolt area, but not the bolt. When they move go back and forth and a little at a time. That seems to work the best for me. I hate easy outs because when they...
Our motors have a 1.85.1 gear ratio. I use 6% slip when working with the numbers. I know it's not perfect, but it worked great for propping my boat and it gives me a ballpark RPM average. If I had...
I don't use a tach, but based on my speed and prop pitch it's around 5700 rpm at wot http://continuouswave.com/cgi-bin/propcalc.pl/
My Yamaha 30 has nothing to prevent over revving in neutral. Nothing has been removed or played with as far as I know. The cdi doesn't have any way to detect gear position either.
I have the same motor and was wondering the same. Yamaha claims that it makes it's 30hp @ 5000 rpm. I was planning on using 40hp carbs, but now I'm going to bore out the factory set. It should be fun...
Please share your findings.
A 4 blade and bigger gear case will add extra drag and less speed. You probably need more power to achieve 40 mph?
Nice little increase. I wonder if reeds would add anything?
MX bikes make a lot more power for sure! A Kawasaki KX 500 probably makes twice as much power compared to my 496cc Yamaha 30hp.
Does any anyone know were I can buy a jet kit for a small Yamaha with Nikki carbs?
Do you think cutting a tuner down would cause a lean condition? My plugs look lean after modding my exhaust on my yamaha 30hp 3 banger.
Good read and thanks for sharing.
Try the bigger carb first since you already have one. I would use which ever carb that looks the best.
The squeeze your referring to is the exhaust were it gets small? My Yamaha 30hp had a bunch of casting imperfections and I removed all of them and it opened the squeeze. Did I screw up by doing that?...
I've been playing around with the West epoxy and I love it. I can't believable how well it bonds to old glass. I'm still unsure about covering it with gel coat? I haven't seen an epoxy based gel coat...