My 2001 lund fisherman 1700 with a 115 yammi 4 stroke seems to have something wrong, it has a 17 pitch prop and is running about 4300 rpms with a top speed between 29-30 mph with 2 people no load! I know their is something wrong because a friend has the same boat and goes about 40 mph with a large load. Any input on possible problem or new prop size would be awesome!
I have a fisherman with a 115 yama I will look at my prop and get back to you but my guess its a prop problem……..did it just start havin problem or has it always ran like that?
bought the boat on craigslist. first time on the water this year since I like in northern Wisconsin. Everything has worked fine on the boat except the motor. runs awesome at 28-30 mph but seems like theirs no more power their once you get going
I have that same boat and had a Yam 115 on it originally. I can’t remember the prop size but I’m guessing it was a 17 pitch SS Yam prop. It ran 38-42 mph at 5500, very load dependent. I repowered it with a F150 Yammie and it’s a totally different boat.
My engine was mounted 1 hole up on the transom. Does yours get up on plane fast or is it a slug? Sure sounds like a prop issue. The 115 Yamaha is a nice motor on that boat unless you’re determined to cruise at 40+, then the 150 is needed.
Are you using the trim and tilt?
Glenn I am using tilt and trim
lundgeye.it has snap and gets on plane like normal but once on plane it seems like we are not gaining any power.
It could be a fuel related problem also check and make sure all 4 cylinders are getting spark, I had a problem like that with my 90 horse johnson last summer turns out I just knocked a spark plug wire lose. If thats not the case possibly in need of having the carbs or injectors cleaned out (whichever it has). Just a couple of simple things to check out
scratch that about the spark plug didn’t pay attention to the fact its a 4 stroke if it was that it would run like garbage
If all else fails, I know Al’s has a diagnostic hookup to their laptop that will spit out any/all faults and give you an answer. Might be worth stopping into Al’s on N Broadway and talk the issue through with them, might give you some good clues. If it accelerates fine, then more than likely the prop is not too tall, leading back to fuel or spark.
Running a similar boat (17 ft lund tyee)and I got a 13×19 prop on my 115 evinrude h.o. 2 stroke. Tops out at 45
I am sure it isnt your prop that prop should over rev the motor if anything,I had a friend who had same problem with his yamaha and he had a dirty injector.I would bet it is fuel related and just needs a cleaning you could try some sea foam.This new gas now days doesnt like to sit for long and will gum things up.I have a lund also very nice boats 
Thanks Guy, I am taking it to my marine tech next week. I was thinking how many rpms im off (1400-1600 rpms) could a prop change really do that much difference?
Do you really think seafoam would work in a 27 gallon tank? (almost a full tank)
Decarbing the motor is a good first step. I think the prop is unlikely to be a problem. This can work wonders and from there if there are still problems you likely need some carb or injector help.
DECARBING FAQ
Since this pops up every other day on some board, try this method, I picked it up on another board and have been using it for awhile now,works great. Tip for the Week Do-It-Yourself Engine Tip; A Simple and Cost Effective Way to De-Carbon an Outboard By Capt. Bob Dunkelberger [email protected] This works for Carbed, EFI, Ficht, HPDI, Opti-max and even 4-strokes… and should be administered after every 50-60 hours of use. First you need a separate small fuel tank. One of those 3-gallon red Tempos works well or an empty gallon milk jug in a pinch, but it might be a bit messier. I use Seafoam over the OEM (original equipment manufacturer) stuff like OMC Engine Tuner or Mercury Power Tune. Note: in the last few years they changed the formula and you have to let them sit up 12 hours. Who’s got time for that? Seafoam does the job in 15 minutes and can be purchased from NAPA, Car Quest or other auto stores. You’ll need 3/4 gallon of gasoline and one 16oz can of Seafoam for each engine. Don’t forget to add 3oz of oil if you are pre-mixing in a carbed engine. Use a 3 ft piece of fuel hose off the small tank. Connect this tank to your engine by pulling off the main tank fuel hose from the intake side of your water separating fuel filter and plug the hose off the small tank onto that fitting. Or you can separate the fuel line on the tank side primer ball, so you can still use your primer. If your engine has a fuel plug then you will also need a fuel plug on the smaller tank’s hose. Start the engine, let it warm up and start pulling the mix into the engine. You may have to increase the idle to keep it running once she gets loaded with the Seafoam. Run the engine 15 minutes at the dock or just cruising around under 2500 rpm’s. Then shut it down and let it sit for another 15 minutes. Restart the engine; the smoke you see is the carbon burning off. Do the whole thing again and let her sit again for 15 more minutes. If she smokes after the second time do it again. I’ve never seen one still smoke after three doses. (I bought a Bronco two years ago that had 95,000 miles on it. When I used Seafoam on it I had the neighbors hanging out of their front doors looking for where the fire was after I started it the first time there so much smoke) The gallon mix should be just enough to do this 3 times. You don’t need a wide-open throttle and you don’t need to change the plugs. The plugs are cleaned at the same time as the combustion chambers. My suggestion is that every 50-60hrs is the optimal time to change plugs in most engines. I cleaned an antique Evinrude once that had a 1/4″ of solid carbon on the exhaust chamber walls by running a 1/2 gal of the aforementioned mix through it. Seafoam, a great product, has been around since the 1930’s and it’s what they used when they were burning straight 4 stroke 40SAE oils in outboards. For you guys with the 4 stroke outboards? Those engines work 10 times as hard as any auto engine ever will and they too will carbon up. Too many are under the assumption that it’s totally the 2 stroke oil that causes the carbon, Wrong… it’s also the additives they put in the fuels today. The carbon inhibitors in 2-stroke oil are there for this reason also. Remember when gasoline used to smell like gasoline, today it smells more like bad cologne. For those guys that like to work the carbon treatment by spraying it down the carbs, Seafoam also comes in spray can called Deep Creep. It’s the same stuff under pressure and notes on the can, “Oxygen Sensor Safe”. After that, if your engine manufacturer recommends a daily additive treatment then do so. The tank and hose are a one-time purchase and the Seafoam is only costs $5-6.00 per can.
thanks norge, going to try that right now!
Quote:
I am sure it isnt your prop that prop should over rev the motor if anything,I had a friend who had same problem with his yamaha and he had a dirty injector.I would bet it is fuel related and just needs a cleaning you could try some sea foam.This new gas now days doesnt like to sit for long and will gum things up.I have a lund also very nice boats
Not a prop issue – I agree above should over rev
I have a V177 Warrior with 115 Merc and a 20″ Lazer SS prop
and have no issue running in the max RPM range
Warrior boat is heavier then 1700 Lund too I think
How long did rig sit B 4 you got it?
Did U fill with fresh gas?
Check oil and see if gas smell in it
Just a few things U can ck – also Welcome to IDO 
DECARBING 4- stroke – U do not need to add oil 2 gas
I change oil(to much oil according to the dipstick) didnt do anything will try carbon thing. But someone at the landing suggested the fuel injectors
Could this be the problem new prop did not do anytjing(19 pitch)
I have same boat and motor, just a little newer. Running 17 pitch prop, I never got much more than 32-33MPH GPS. I went with a 15 pitch prop as I was trimming way up to get to 5,800 rpms. I get there a little easier now, and the prop doesn’t blow out as much in turns. Aluminum prop. If you are trimming right, and only getting 4200 or something rpms, there has to be something else.
This said, it was mentioned before… if you want top speed out of the boat the 150 is the right set up. I saved several grand at the time on the 115, and live with the top speed. Regardless of weight vs other manufacturers, this boat pushes a fair amount of water. Couple shops I have spoken to over time all seem to have the same thought on the early to mid 2000’s Yamaha four stroke 115 motors.. a little heavy and doggy compared to others of the same displacement. Real solid motors, just not a real performer on top end. I tend to agree with that theory.
Quote:
I change oil(to much oil according to the dipstick) didnt do anything will try carbon thing. But someone at the landing suggested the fuel injectors
Could this be the problem new prop did not do anytjing(19 pitch)
sinz8
if u went from a 17″ prop to a 19″ you should have dropped Rpm’s by a couple hundred 
– both props Aluminum?
when you changed oil and seen it was high – did it smell like gas?
I would also do a compression test
then decarb the motor – that should clean the injectors some
I did a compression test on a motor I got – then the decarb – then did the test again and seen a little increase
Good Luck and let us know how U come out
weather finally going warm up so a guy can do stuff like this
I just installed a set of Chris Carson Reeds in a motor I have
and can’t wait to SET THE WATER FIRE 
Does anyone have any opinions on Norge’s seafoam cleaning technique. I have a 115 2 stroke yamaha that i just bought and was thinking i might do this to make sure it is clean and good to go before putting it through it’s paces.
Ive just heard varied opinions on the pros and potential harm seafoam may do to motors.
Run ringfree and you would be just fine.
Hello all, I have found a fix. My marine dealer changed the plug and said that we wouldn’t even notice the plug during low rpms or idling we took it out on the lake drove great! 5600 rpms top speed of 41-42 but we were just checking our boat out and I was driving it around at 7 or so mph and we went to take off it bogged down and was doing the same crap 28-30 mph 4200 rpm I shut it off for a minute took off it ran fine
What’s the deal and suggestions?
Take it back to the dealer and have them lake test the boat with the computer hooked up. It sounds like a fuel issue. Sometimes the only way to see the problem is when the boat motor is under load when running on the water.
If the motor has individual pencil coils, they sit on each individual spark plug, a bad coil will show up as a fouled plug. They usually act up when they get hot after running a while. Then when cooled down work fine. Back and forth, back and forth. Hard to diagnose except on a hot motor while actually acting up.
If you are getting a fouled plug consistently on one cylinder you can exchange the coil/wire to a different cylinder. If the cylinder/plug fouling change then you know for sure it’s the pencil coil. But, dealer should rectify either through warranty or your own out of pocket repair payment.
I found the problem! It was partially plugged injectors! hard fix took about 2 weeks for the dealer to figure it out! thanks for your help guys!
Thanks for posting the root cause, what did the dealer do to fix the problem?
I would run Mercury QwikCare every few tanks of gas. On my 10 year old BMW motorcycle I had some issues after winter storage, low / rough idle, and surging while under light throttle. The bike has fuel injection and I tried the QwickCare. By the second tank of fuel all the issues cleared up. For me it works as a maintenance product, not a cure for a fully clogged injector, but seems to clean up a partially clogged one.
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