89 Mariner WOT specification?

[jon-milford-ct]

Finally got all the stuff worked out with the motor thanks to countless hours (combined) of searching and testing. First it was one cylinder not firing and it followed the coil. New coil, same problem! Plugs, wires, more searching. Guy I bought it from said he thinks carb needs to be cleaned/rebuild. NOT! Think he chased same problem And already had carb done because it was cleaner than clean. So more searching while waiting for carb kit (while I had it off might as well) and found some results about the reeds. They looked fine as far as I could see but decided I might as well pull and get a better look. Going back, the motor smoked a lot, left lots of fuel and oil in the bucket so I originally thought the float might be punctured. I found a video of the same motor on YouTube and same problem. To many different suggestions to count. So anyways, when I pulled the reeds I found the bottom of the gasket and sealer real oily and thought BINGO!!!!! Now the motor is running perfect. Time to get the tach working. I saw it work a few times out on the water but now its just dead. Search, test bla bla bla..... Got a new Rectifier and that fixed that! This is a 1989 16ft fisher freshwater fishing boat. Very light package. 25hp 2stroke mariner. WOT its pushing between 19-21MPH @3000/3100rpm Prop is 48.19640 A10L 13P Motor serial is I can not find anything in searches telling me what my WOT should be. My last merc had a tag on it telling you all of that. I found nothing. But I suspect I'm way to low. Should be up somewhere like 4500 to 5500rpm, no? Each increase in pitch will give me like 200 more rpm? If I raise the rpm up to the range will the boat go any faster? Im looking for asuch speed as I can get. Don't care about the hole shot. Right now she plains but just barely with all the freshwater fishing gear and crew of 2.

 

[jon-milford-ct]

Motor serial c153680

 

[racerone]

Compression is ?------------Lower crankshaft seal been checked ?.------Exhaust passages below the block checked for blockage ?

 

[jon-milford-ct]

Compression is ?------------Lower crankshaft seal been checked ?.------Exhaust passages below the block checked for blockage ?

Compression is great. That's the first thing I checked. Was close to 120 each. Others I have not checked. Do you suspect there is something else wrong because as I said she is running perfect. Just need more rpm to be in the correct rpm range, UNLESS I'm supposed to be down around 3000rpm. I'm getting full open on the butterfly.

 

[racerone]

At 3000 RPM your motor will not develop proper power.-----You also risk damage to the motor.----Step #1 is to confirm that your tachometer is giving you the correct reading.-------I suspect it is not.

 

[Faztbullet]

A 13 pitch prop sounds way to big for your set-up.

 

[jon-milford-ct]

Yeah I'm about done playing with it for the season. Gonna pull the motor to replace transom wood and axle to install ezlube spindles. Over the winter I plan on getting tto tach and first thing in the spring I'll try to get this sorted. I had it out today and just doesn't seem like its reving up like it should for a 2 stroke.

This boat it way way lighter than the 04 tracker I had with 25 4s few years ago. That was very heavy comparing the 2. This Fisher doesn't even have decking with storage. The floor is one whole sheet of thin aluminum with alum ribbing under it.

 

[jon-milford-ct]

Ok got it all back together, got the tto tach. what should my settings be set at? I ran the motor and played with settings but am unsure what it should be set at. I noticed that if i hold the tach in my hand the rpm doubles.
If i set it to 1 it seems to low and set to 2 it seems a little high