77' Johnson 115 Maidencraft WOT Question!

[PGH Mike]

So... I bought this boat for 300$. Put a new steering rack in, fixed a few bugs, took it out on the water. I'm not sure the pitch or any info on the prop, because nothing is stamped on it.

This is my first boat so bear with me here. Let me tell you was going on.
Info:Maidencraft 16' 115 Johnson TNT bass boat, exactly like this "except not at nice":http://cdr.vflyer.com/home/flyer/home/1819666

We take it out, go full throttle, with 2 of us, it'll rev real easy up to about 2800 RPM, then take 15-25 seconds to plane out. Once planed i can trim the motor to run at about 4300 RPM and 35 mph, maxed WOT.
The boat came with 2 props, we put the one on thats stainless, and the boat would only go about 2500 RPM with no plane.

What we did:
Checked stator reading (fine according to manual)
Fuel Lines
Cleaned Tank
Plugs
Seafoam
Replaced Steering Linkage (irrelevant)
Fixed throttle linkage (correct to manual)

QUESTIONS: 1. From what i've been reading, this boat should revv out to about 5500 RPM, which would give us another 9-11 mph. Which would be in the "normal range" for this. Is Revving to only 4300 ok? What should i Test, what should it run?
2. Should it take 15-25 seconds to jump onto plane? Or should it just jump up rather quickly, cause from what i remember, most boats just jump up.
3. Via Google maps, we traced out our river router to be around 30-35 miles, and used about 12 gallons of gas, is that normal as well? Most of that was WOT.
4. If this is not normal behavior (which I believe the lack pushing onto plane and also not topping out is not) Then what else should I check? I'm going to check compression sometime, what should a good readout say?

Right now the boat is docked, and I'm welding/grinding/painting the trailor, because its got a pretty bad case of cancer.

Anyways, If some of you fellas could give me some feedback after reading this novel of a post I wrote, that would be fantastic. Like I said, First boat, First post, give me some feedback/pointers.

 

[DJ]

Re: 77' Johnson 115 Maidencraft WOT Question!

You're not running on all four cylinders.

Did you do a compression test? If not, do so. Each cyl. should be over 100 psi and within 10% of each other.

Any of your spark plugs look real clean? If so, you popped a head gasket. Easy to change on that engine.

If you haven't rebuilt the carbs, you're overdue.

 

[tashasdaddy]

Re: 77' Johnson 115 Maidencraft WOT Question!

your link does not work. agree with above. the rule of thumb for gas consumption is move the decimal of the hp to the left one place, 115hp + 11.5 gallons per hour, at wot.

 

[PGH Mike]

Re: 77' Johnson 115 Maidencraft WOT Question!

I will check compression here in a week or so, Until then, one of the spark plugs did look real clean, like it hadn't fired.

Could that be a bad coil? Like that coil is not firing?

Or does a clean spark plug always=bad head gasket?

 

[PGH Mike]

Re: 77' Johnson 115 Maidencraft WOT Question!

Checked Compression, left side = 120, 118. Right Side = 114, 112. They are all within 10% and I figure that's pretty good for that engine.

Also found out my coil pack is not sparking... at all, on one piston, sooo I think i've found my problem.

Tmrw I'm going to swap out coils, and see if it will fire will a different coil, or if its a powerpack.

 

[wavrider]

Re: 77' Johnson 115 Maidencraft WOT Question!

Sounds like you are on the correct path to getting the old engine running correct.

You need to get a spark that jumps a 7/16" spark nice and blue color.
You can get a spark tester at any of the auto parts store or build your own.

Clean those carbs, Clean the carbs,,did I mention to clean the carbs??
The carbs wil get gum and varnish in them from sitting up. Just because the engine runs does not mean it is running correct. Clean them carbs, soak them in carb cleaner and use a wire to push through the jets, then compressed air to make sure they are good and clean.

This will not only give you peace of mind in knowing it is not a fuel related problem but also will let you know you wil not be running lean and the engine , pistons wil get all the fuel and lube they need.

Check the timing, Use Joe Reeves triming method at the top of the page, works great.

There can be alot of corrosion in the spark plug wire boots. Pull the boots and see if there is any rust that may need to be cleaned.

Clean all the ground connections on your amplifier and coils. Pull the battery ground from the engine block and clean all the corrosion off from there, Those year engines are known for corrosion build up in the ground areas.

You will want to change the water pump and thermostats also. Make sure the cooling system is workng well.

As long as you keep good fuel properly mixed, and the cooling system is working fine, the old engines will run practically forever.

I have a few of the v-4's, they are thirsty old engines but dependable as all get out if maintained properly.

 

[PGH Mike]

Re: 77' Johnson 115 Maidencraft WOT Question!

a all the plugs seem to have a really crisp blue spark, you can hear it cracking, and I felt it a few times yesterday haha.

Well, I just picked the boat up umm, about two months ago, and for the past 3 weeks i've been redoing the trailer, I docked it up while I did that so engine work as been sort of sparse.

Its basically a winter project, get ready for next years fishing season.

Regaurdless, i'm going to swap the coils today, between a known good cyl, and the bad one, just to make sure its the coil pack and not the amplifier.
I looked at the price of a new coil, and its like 25$, so If i can get away with spending just that, that would be great.

I had taken it out back before I got the tach working, and it was running 40 mph, and I thought that was just great, but apparently it wasn't because I was only running on three pistons!

But I think for 300$ for boat and trailer, I made a pretty good investment, and i'm hoping the old saying about the two best days of your life don't stand true.

The carbs well def get rebuilt/cleaned this winter when its parked in the garage (along with new paint and carpet on the boat) and the hydraulic trim/tilt systems will get rebuilt.

Along with a new fish finder, and whatever else I can get my hands on!

BTW, does anyone know of any good online parts stores?

 

[Timmstng67]

Re: 77' Johnson 115 Maidencraft WOT Question!

Try http://www.bestboatparts.com/ Fast shipping Great customer service Great prices.

 

[Tim Frank]

Re: 77' Johnson 115 Maidencraft WOT Question!

http://www.garysmarine.com/

 

[PGH Mike]

Re: 77' Johnson 115 Maidencraft WOT Question!

Thanks for the sites guys.

Well, I checked the coil... The coil seems good, I switched wires 2 and 4 on the coil, so that I could check if it was the coil, or if it was the power pack, and the problem stays with the power pack. Not sure if i'm explaining it right? Basically cyl 2 used to spark before i switched wires, and now does not, cyl 4, which did not spark before, no sparks when the engine is being turned over.

So, I'm fairly new to marine engines, but I mean, I'm a fairly good car mechanic, so....

Is this basically a no brainer and I need a new power pack, or could it be something else like an amplifier (do I even have one of those?) or maybe a stator not sending signal to fire there?

What else should I check before I go spend 100$ on a power pack. (other than your grounds and whatnot, simple stuff)

 

[wavrider]

Re: 77' Johnson 115 Maidencraft WOT Question!

If I understand correctly, you swappd the coil input wires around on the amplifier?

If the coil was sparking before the switch, and now it is not sparking, then it is either the amp, or input to the amp, or wires broken somewhere.

Before you throw an amp at it inspect all the wires leading to the amp coming from under the flywheel. If you can pull the flywheel and inspect the pickups, sometimes you can just adjust the pickups in a little on the ring and it will be enough to get the proper voltage to the amp to fire it.

Take cover of the amp and loosen and retighten all the screws connecting the wires to the amp.

Also check the grounds on all the coils, even though it did fire.

I do not have the link here but tomorrow when I am at the office I will post the link to troubleshoting your ignition system with resistance values and what the voltage values are for the ignition system.

The wires do get old and brittle with age, the timing advance also moves the harness leading to the amp, sometimes the plastic harness cover gets brittle and cracks, cuting the insulation on the wires and shorting them out intermittently/constantly.

 

[wavrider]

Re: 77' Johnson 115 Maidencraft WOT Question!

http://www.boatpartstore.com/tips.asp
http://www.boatpartstore.com/page40.asp

found the links

 

[PGH Mike]

Re: 77' Johnson 115 Maidencraft WOT Question!

Hey thanks for the ideas/links wavrider (because I don't know your name.)

My one buddies is actually an electrical engineer, and is real good with wiring, and testing things, i'll get him to stop by and we'll see what we can come up with.

I'll post back on friday, that is of course.

 

[PGH Mike]

Re: 77' Johnson 115 Maidencraft WOT Question!

Well, I went ahead and checked out the Power pack (about a month ago) and it seems cyl 2 the problem cyl was not throwing a spark.

Did some testing, put a new power pack in, ran like a raped ape.

With the standard prop I was getting about 55mph down the river at 5300 rpm.

With the speed prop i was getting about 63mph at 5100rpm.

ATTENTION: For the fella who is not getting spark, and you have similar engine with the sensor wire 1,2,3,4 and then cyl wire 1,2,3,4. What I did to figure out it was the power pack was I was not getting spark at cyl 2, so i swapped sensor wire 2/4 to make sure that 2 was sending a spark, which it was because when i has sensor wire 2, hooked up to the spot where sensor wire 4 went, it sent a spark to cyl 4, so I knew there was a break between sender wire 2/cyl 2.

Well, lets have a running total:
Boats+title+transfer (450$)
Fixing the trailor (100$)
Steering Cable (180$)
Power Pack (120$)
Misc (50$)
---------------------------
(900$)

Granted, I still have to paint it, carpet it, get a fish finder, put some rod holders on, so i figure for about 500$ more dollars (in boat math that = 800$ sadly) and i should have a nice old fishing boat, ready to crush some bass.