why wont it go FASTER!!!

[Willyclay]

Re: why wont it go FASTER!!!

1. it is a 2 stroke

The way I read the Spark Plug Chart at the link below, your 2004 motor should be a four-stroke. Last two-stroke 15HP was 2001.

http://www.boatsetup.com/SparkPlugChart.pdf

I think Suzuki was building all the smaller Johnson branded motors for BRP at that time.

How about posting you motor's model number so we can be certain what you have?

 

[steelespike]

Re: why wont it go FASTER!!!

the motor should have plenty of time to cool we get to the hole by 4am hunt and so-on with the motor in the freezing water till 9am

Your probably right; I'm just saying if it continues fouling plugs check for good spark.

 

[steelespike]

Re: why wont it go FASTER!!!

The way I read the Spark Plug Chart at the link below, your 2004 motor should be a four-stroke. Last two-stroke 15HP was 2001.

http://www.boatsetup.com/SparkPlugChart.pdf

I think Suzuki was building all the smaller Johnson branded motors for BRP at that time.

How about posting you motor's model number so we can be certain what you have?

I checked an engine spec chart there was a 2 stroke 9.9 and 15 available in 03.Ill bet its a carry over either dealer or factory stock.

 

[smokeonthewater]

Re: why wont it go FASTER!!!

Spark-plug: NGK B8HS
I just do 40:1 to 50:1 mix
I keep it in the 3 tilt pin hole
Prop Pitch: 9.25X11 (aluminum)
32 mph when it was me and fishing stuff (no battery)
I use TCW3 synthetic from Quicksliver

BTW... lets make sure we are comparing apples to apples.. Is this 32 mph with a GPS?

 

[JBooth]

Re: why wont it go FASTER!!!

No, I have a speedometer on a Lowrance Sonar. I installed the little wheel at the bottom of the transom.

 

[fishrdan]

Re: why wont it go FASTER!!!

When adjusting motor trim you will likely find that a notch isn't quite enough and the next up is too much and it stasrts to porpoise.

Sometimes you can move the gas tank and or gear forward to tame it.If its a gentle bounce just leaning forward will settle it down.

Since you have a GPS, use that to test the different trim pin settings. Run the outboard at WOT in each trim pin hole and see what the top speed is, then select the fastest setting.

Your buddy hauling around extra gear could actually benefit his speed if it's balancing out his boat better than your boat. If you have all the weight in the stern of your boat, that's going to be a performance killer. I have most of the "gear weight" mid-ship in my boat to balance it out and it's been the same for all the small boat's I've owned. Small boats are very sensitive to load balance, so start shifting things forward (fuel tank, battery, anchor, etc.) like SS suggests.

When the OB starts to act up and sputter, try squeezing the primer bulb and see if this helps. If squeezing the primer bulb straightens out the sputtering, you have a fuel delivery issue, tank vent not open, bad primer blub, weak fuel pump, air leak in the fuel hose or connection.

I think you said you completely drained and re-filled the fuel tank, but did you see if there was any water in the old fuel? IE: dump some into a clear jar and see if any water separates to the bottom.

 

[fishrdan]

Re: why wont it go FASTER!!!

No, I have a speedometer on a Lowrance Sonar. I installed the little wheel at the bottom of the transom.
View attachment 130100

Those speed wheels are not really accurate at high speed, though they will help identify top speed for different trim positions. I used to have an Eagle sonar with paddle wheel speedo on my jon boat and it read I was going 26-27MPH, when I was actually doing 22-23MPH.I figured this out by running a couple long distance runs, 10-20 miles. I haven't GPS'ed it to see what the actual speed is though.....

 

[JBooth]

Re: why wont it go FASTER!!!

I suspected this as well. I have timed my run and it seems to be within 1-3 mph. I did 5.5 miles in around 12 minutes (27mph) and was reading about 28 mph the entire way.

 

[all duck'd up]

Re: why wont it go FASTER!!!

ok so updates... my buddy came by yesterday to help me check the spark on the motor and everything checked out good. but while he was looking he found a few issues with my gas line conections. we replaced them and went ahead and re-did the lines and cleaned the fuel pumps screen. the motor hasnt ran this good since i bought it hopfully it wont act-up on the water anymore. never knew that small of a leak in the gas line could make that much of a difference. :facepalm: i ran it in the yard for a good 30-45 min no hickups bumps backfires or anything and i even think the throttle response is better.

i think its ready to eat a old e-rude

 

[all duck'd up]

Re: why wont it go FASTER!!!

Since you have a GPS, use that to test the different trim pin settings. Run the outboard at WOT in each trim pin hole and see what the top speed is, then select the fastest setting.

Your buddy hauling around extra gear could actually benefit his speed if it's balancing out his boat better than your boat. If you have all the weight in the stern of your boat, that's going to be a performance killer. I have most of the "gear weight" mid-ship in my boat to balance it out and it's been the same for all the small boat's I've owned. Small boats are very sensitive to load balance, so start shifting things forward (fuel tank, battery, anchor, etc.) like SS suggests.

When the OB starts to act up and sputter, try squeezing the primer bulb and see if this helps. If squeezing the primer bulb straightens out the sputtering, you have a fuel delivery issue, tank vent not open, bad primer blub, weak fuel pump, air leak in the fuel hose or connection.

I think you said you completely drained and re-filled the fuel tank, but did you see if there was any water in the old fuel? IE: dump some into a clear jar and see if any water separates to the bottom.

i was under the impression that the least amount of boat in the water the better so i stuffed everything into the back battery, gas can, and anchor; thinking if it was twards the front it would weigh it down and keep it from coming up on plane.

i guess i will start by moving my battery into my dry box

thanks fishrdan and steelespike

 

[all duck'd up]

Re: why wont it go FASTER!!!

as to the gps i used was on my phone sometimes the service isnt so great so i use mine and my buddy also uses his

 

[steelespike]

Re: why wont it go FASTER!!!

Prop calculator says 32 isn't possible with an 11" prop 2.42 ratio, If the motor can reach 7000 (some question if an 05 2 stroke is rated that high) 28.3 is the max speed. at 6% slip.Minfo says the 15 2 strike went to 6,000 rpm in 95. 11" is the highest pitch here at iboats.
I've lost track; do we know your prop size?

 

[all duck'd up]

Re: why wont it go FASTER!!!

Prop calculator says 32 isn't possible with an 11" prop 2.42 ratio, If the motor can reach 7000 (some question if an 05 2 stroke is rated that high) 28.3 is the max speed. at 6% slip.

24.5 would be good enough just to get me out front but 28.3 would be better! haha

 

[steelespike]

Re: why wont it go FASTER!!!

i was under the impression that the least amount of boat in the water the better so i stuffed everything into the back battery, gas can, and anchor; thinking if it was twards the front it would weigh it down and keep it from coming up on plane.

i guess i will start by moving my battery into my dry box

thanks fishrdan and steelespike

It depends on the balance If it seems stern heavy it may need to have some more forward. My old 15 ft kit boat was a little bow heavy and I ran with me sitting on the rear deck next to the motor the gas tank and battery on the rear seat and the motor trimmed in the 4th notch. indicated speedo speed was occasionally 27 the max rated speed for the stock 18 hp.I know now that the motor was probably too deep because I never had any venting trouble unless I put it into a sharp turn and it started to slide.

 

[all duck'd up]

Re: why wont it go FASTER!!!

It depends on the balance If it seems stern heavy it may need to have some more forward. My old 15 ft kit boat was a little bow heavy and I ran with me sitting on the rear deck next to the motor the gas tank and battery on the rear seat and the motor trimmed in the 4th notch. indicated speedo speed was occasionally 27 the max rated speed for the stock 18 hp.I know now that the motor was probably too deep because I never had any venting trouble unless I put it into a sharp turn and it started to slide.

when you say venting problem you meen when air gets in the prop and it revs really high?

the bow on my boat should be really light the dry box is loaded but there isnt anything heavy in it (life jackets, paddle, couple tools, spare sparkplugs thats about it for up front other than when i'm going hunting i'll have the decoys up there too

 

[Chinewalker]

Re: why wont it go FASTER!!!

Keep in mind - props are like gears in your car. Going up in pitch is like shifting up in gear. For example, if you're presently running a 9x10 at 5000 RPM, going up in pitch to a 9x11 might drop your RPM down to 4600. You will likely go SLOWER in the process. Now, if your motor is spinning 6200 RPM with the 9x10 and you then try the 9x11, you RPM might go down to 5700, in which case you might go FASTER in the process. Why? Say your motor is rating its HP in the 5500-6000 RPM range. Going over or under that is out of its power band. It is best to prop your motor to be near the high end of the range to better accommodate changes in load and still get into the happy zone RPM. It is usually the fastest you'll get out of your rig. If you load up a cooler, bring a buddy, or have a really good day of fishing you're covered. Changing set-up can also change the prop needed - motor angle, height, etc. may allow a taller/higher pitch prop to be used and still get into the band. Like your car - if you're going up hill, it downshifts (lower pitch) to bring the RPM up so you can maintain speed as load increases (buddy added). Your car is most efficient when it's within it's own happy zone.

As noted above, get more of the boat out of the water. Get as much of the lower unit out of the water (paint sticks under the clamp brackets work great!) Experiment! And buy/borrow a tach if you can... Otherwise you're shooting in the dark...

 

[steelespike]

Re: why wont it go FASTER!!!

Correct. For many years refered to as cavitation even by the manufacturers.
A little more trim/balance info::
My 18 foot Crestliner utility with a tiller 50 Evinrude is a little light in the bow.
I put one or 2 6 gallon tanks near the bow and I still sit with my butt against the transom
when I want to really go.
Motor is in the second notch 3rd notch porpoises.
For the most speed it probably would be best with the tanks closer to the stern. But the boat will occasionally kite when really pushing it into the wind.
When adjusting your trim there is usually a notch that will porpoise. Let us know what you find.

 

[all duck'd up]

Re: why wont it go FASTER!!!

Correct. For many years refered to as cavitation even by the manufacturers.
A little more trim/balance info::
My 18 foot Crestliner utility with a tiller 50 Evinrude is a little light in the bow.
I put one or 2 6 gallon tanks near the bow and I still sit with my butt against the transom
when I want to really go.
Motor is in the second notch 3rd notch porpoises.
For the most speed it probably would be best with the tanks closer to the stern. But the boat will occasionally kite when really pushing it into the wind.
When adjusting your trim there is usually a notch that will porpoise. Let us know what you find.

the 3rd notch is the best one that ive found the 4th had that venting problem but i will test it after moving the battery and throwing the anchor in the shed.

i called and talking to my buddy with the e-rude he said that when i am riding pretty good the back of my boat is really low in the water (like inches from the top) so i will look at ajusting the weight in my boat today.

i was wanting to install a radio so this will be perfect for me to mount it in the dry box by the battery

 

[fishrdan]

Re: why wont it go FASTER!!!

i will test it after moving the battery and throwing the anchor in the shed.

Keep the anchor in the boat, it might give you the added ballast you need fore or aft. You want to balance the boat with everything it will normally run with. When I first bought my jon boat I took it out with several batteries, trolling motor, fuel tank, gear, and started moving them around to see where they needed to be located for best performance. Then, after the first run to see where everything needed to be located, I hacked the boat apart and customized it...

I used to have an old Coleman Crawdad, that if running long distances, I would take the trolling motor of the transom and lay it in the bow. That 40# ballast shift made a HUGE difference, probably 5MPH if not more. I highly doubt you boat is that sensitive, but think it will respond to load balancing.

 

[all duck'd up]

Re: why wont it go FASTER!!!

drew up a plan of what i'm thinking about doing with my dry box so i can move the battery up farther in the boat