115 yamaha tech questions

[biggercb]

I have purchased a 2001 VIP 17ft fish and ski boat. It came with a 2001 115hp 2 stroke Yamaha outboard.During the test drive the boat is running a 19 pitch 13.5 dia 3 blade aluminum prop. Runnin in the 3rd hole from the top. I plan to fish, slalom, barefoot. Wide open with trim all the way down approaches 6000rpm. With any trim at all the rpm runs over 6000 @ 47-50mph. (from the boat speedo--i dont have a gps--yet). Two people in the boat, no gear, 1/4 tank fuel.

Questons:

Is the cavitation plate on the engine supposed to be level with the bottom of the boat? Or does it depend on other factors.

Is the RPM too high?? Or is this likely because of minimal weight in the boat?

Would a 115 hp benefit from a stainless prop?

I noticed in a search that a yamaha prop will fit a mercury lower unit, does this apply to the smaller v4's?

If I can get the weather to cooperate I will get some pictures of it running with more people payload in the boat. My main concern is the 6000rpm. Is it safe to run it this fast?

Since the mrs. will be taking the boat out also, I was thinking of leaving the oil injection intact? Does anyone have any input?

Will the 115hp yamaha charging system be able to support a stereo system? With or without an small (maybe 200w) amplifier? I looked up the charging system on yamahas website and it was rated for 20A @ WOT. Is my 2001 an identical engine? Or have they changed it?


Thank you ahead of time for any input.

[captcarb]

I had one of those propped like that. You will need that prop or even a 17 for skiing. If you want to run flat out I would get a little more pitch. I think it is easier to just back off the throttle a little. My ski boat is an 18 with a 17 pitch on a 150 Johnson and will easily hit the rev limiter at 6100. I just don't run flat out. It pulls like a train.

I ran the oiler with no problems, but I had problems on the Johnson I have now and I premix. That particular Yam is one of the best motors ever in my opinion.

jim

[mackeral5]

add a little cup if you need to get the rev's down. cut the rev limiter loop and let it spin up to 6000-6500. if you don't get rid of the rev limiter the rev limiter WILL kick in and you'll know it----mine kicks in at 5800 and sounds a lot like a crotch rocket hitting the limiter...I put a switch on mine so I can turn it back on for diagnostics, cutting the limiter disables warning horns as I am told...good luck

[shawnjetton]

i had a 115 yamaha on a 20 ft. almn. flat with a 19 power tech and it ran high rpms like that. i also have a 24 raker that i would run on it during the summer just to ride around and it brought the rpms down to 56-5700 and went about 54 mph. still have prop if u wana by it $150 + $15.00 shipping

[iammarcuse]

Too many revs! You want to keep that V4 under 6000. Your 19" may be fine for skiing and towing, but you should have no trouble turning a 21" SS. I run a 130 Yamaha (which is about the same on holeshot, the 15 ponies are all between 5500 and 6000 RPM) and I run a 21" SS everyday, including for pulling skiers. 5900 @WOT. You can run small hub Yamaha or Merc props.

[mackeral5]

Just my personal experience with 1 yamaha 115. It's a 2002 model that came with a boat won in a tournament--a Cobia 184, 1950# dry hull weight center console. After putting around 50 hours on it I started mods---heads, carbs, exhaust plate, tuner, reeds, intake work, etc. These mods were performed based on input from the yammie gurus on the board and many hours of conversation with John at Hydrotec and Ray N in Tennessee. All recommend no less than 5800 rpm at WOT.... I routinely run mine 6100-6300rpm for 30 minutes to an hour at a time. Hour meter currently shows 435 hours of being ran like this. I'm sure it will eventually blow, but 435 hours of abusing a v4 pushing a heavy boat (3000lb fully loaded) isn't too shabby. Still runs like a champ and man the sound gets better each 100 rpm increment above 6000!!!! I hate to admit this is all running normal quicksilver oil from wallie world.

Just my experience with 1 particular motor....good luck with yours.

[Ray Neudecker]

like Mike said let it turn up. They like it. A good stainless prop would be first on the list. Limiter is at 6100. You can clip it and alarm functions still work.
The standard 21 Yamaha worked on a lot of boats.

[biggercb]

Thanks for all the replies.
It seems that it should have no trouble turning over 6000. I think I will stick with the 19pitch aluminum and be on the lookout for a 21pitch SS yamaha.

Since the Mrs. says she wants to take it out, for now I will leave the oil injection intact and if I cut the limiter wire I'll put a switch in it like Makeral5. While on the topic of the rev limiter, if I decide to clip it, what is a safe max rpm to run?? If 6100 is the limiter then 6300? not over 6500?

Thanks for all the info.

[Dingie 2]

I have a perfect 21 pro series yamaha pro . It a ''10'' . $250.00 TYD. Joe R

[mackeral5]

I'm still running oil injection, but it is somewhat of a concern in the back of my mind. I just don't think the way my boat is used between me and my wife that I can risk her filling it up and forgetting to add oil....for that matter I could easily do the same thing. boat lives in the water, gets sporadic use 24/7 so until you hear me crying about a blown powerhead due to oil injection failure, oil injection is the only way I will go!

[biggercb]

Thanks for the advice.
Dingie, I want that prop but I had probably wait until my tax refund arrives.

[Dingie 2]

biggercb, It's sitting in the garage not being used. E mail when your ready. Joe R