1996 Rude Power Pack questions

[ondarvr]

Re: 1996 Rude Power Pack questions

A rev limiter typically causes an audible miss and rough running when you hit it, not a smooth bog or surging, a bad PP can do just about anything though.

If the surging is on and off like a light switch then its electrical, if its smooth and just wonders up and down then its normally fuel related.

 

[SparkieBoat]

Re: 1996 Rude Power Pack questions

it was on and off....but only happened on one run about 3 times..cannot get it to do it again...you could tell the surges were powerful though even though they were quick ( about 2 secs each. ) it is like I got about 50 horses waiting to be released. I am going to pick up a set of champions QL78YC today, set gap to .030 and see what happens..I will also be testing a 23 pitch prop today and see how that effects it. it was warm yesterday..a little chill in the air today, better wear my jumpsuit. thanks again for everyones suggestions and help I really appreciate it. this forum has been a goldmine of info.

 

[CharlieB]

Re: 1996 Rude Power Pack questions

Many of the J/E power packs work perfectly fine with the NGK resister plugs, HOWEVER........

the SPECIFIED Champion plugs use a slightly different styletype resistance, this difference can be problematic to some powerpacks because of the Radio Frequency created by the ignition current thru the spark plug causing interference with the powerpack at HIGHER RPMs.

J/E High RPM misfires are usually cured with a simple spark plug change to the specified Champion plugs.

 

[SparkieBoat]

Re: 1996 Rude Power Pack questions

does not seem to be any mis firing going on..changed to the recommended champions QL78YC gapped at .030 could not tell any difference at all. with the 23 pitch prop it got to about 4200 RPMs around 37 MPH. It comes out of the hole pretty good..it gets to 4000 RPMs and about 35 MPH in about 3 secs from idle. a slight hesitation at first but once it gets going it just winds out fast. I saw a small amount of water coming from the head on the drivers side of the motor. Pulled head..thermostat seal is leaking the o-ring on the #3 piston is also damaged about a 1/4 " spot is torn slightly. Maybe enough to allow some water into the piston. piston and cylinder wall looks about the same as the other 2. compression test was pretty even back when I tested it. I remember there was one slightly low cylinder..maybe this was the one.
got new seals on the way..I was not able to find on any boat parts website, the small seal that goes where the water pressure gauge plug-in is, also could not find the tiny seals that plug all of the 1/4 " holes all around the block, must be 20 or so of them. any other suggestions

 

[CharlieB]

Re: 1996 Rude Power Pack questions

The correct plugs should have cured your high RPM problem but with the larger pitched prop you won't know.

Also that larger prop is going to seriously shorten the life of your motor, even running at lower throttle settings that pitch is overworking the motor.

Put the old prop back on to confirm that you have cured your WOT rpm problem, THEN prop the motor to run at or near the max rating, the motor will last MUCH longer once the load is correct.

 

[SparkieBoat]

Re: 1996 Rude Power Pack questions

no change with the 19 pitch prop..the plugs made no difference at all. Hopefully I have found the problem with the water leak. We will see. By the way this is a 150 HP motor on a 17.5 McKee Craft which is 3K lbs loaded. I have friends with much bigger boats than mine running 19 and 21 pitch props. I feel like my motor should easily spin a 23 pitch prop well over 5500 RPMs. It should be able to spin a 19 pitch prop way past the rev limit of 6100. I went to this web page http://go-fast.com/boat_speed_predictions.htm , I put in 3000 lbs 135 HP and a 250 constant and it calculated my potential top speed to be 53 MPH..I have not gotten past 38 yet. I would be happy with anything real close to 50 and this is what I expect this motor to be able to do on my boat. I have a 100 HP motor that I am sure would push it as fast as I am going now. the boat had an 85 HP motor on it when I purchased it and it was the original motor that came on the boat from the factory. And I assume the 85 pushed this boat over 30 MPH.

 

[ondarvr]

Re: 1996 Rude Power Pack questions

The 23 may be the correct prop, but there's no way to know unless the motor is running correctly and going up in pitch to correct a poor running condition "may" cause problems, that's why it was suggested you don't do it. If water is getting into that cylinder, the plug, piston top and head would typically be very clean with no carbon at all.

 

[SparkieBoat]

Re: 1996 Rude Power Pack questions

i was testing to see if my RPMs would be limited to 5300 again..It was limited to that on both 19 and 17 pitch props..and I suspected the power pack, when it was limited to 4200 RPMs with the 23 it showed me that I have something other than a faulty rev limiter going on. The boat is not in use and is still in the "working on it" stage. So I have only taken it out for short test runs. I have had multiple problems with this motor, I have replaced the fuel pump, intake manifold gaskets, clutch dog and found/fixed a place where water was getting into my gas tank. so it has been one thing after the other. It appears to me that someone else had the heads off before and I think they swapped the heads around because the screw holes for the cover for the big electrical connection coming from the remote, appeared to have been used on the drivers side head. hopefully the new seals will fix my problem..Am I right in assuming that if my #3 cylinder was drawing in a small amount of water it could cause low power at top end??

 

[SparkieBoat]

Re: 1996 Rude Power Pack questions

the piston/cylinder that I suspect water invasion did have the same amount of carbon as other cylinders...so maybe it is not the problem..

 

[SparkieBoat]

Re: 1996 Rude Power Pack questions

i also did do a decarb on the motor recently as well, forgot to mention that..but the piston tops had a coating of carbon with only a couple of dime sized patches on each piston where it was silver.

 

[CharlieB]

Re: 1996 Rude Power Pack questions

it was on and off....but only happened on one run about 3 times..cannot get it to do it again...you could tell the surges were powerful though even though they were quick ( about 2 secs each. ) it is like I got about 50 horses waiting to be released. I am going to pick up a set of champions QL78YC today, set gap to .030 and see what happens..I will also be testing a 23 pitch prop today and see how that effects it. it was warm yesterday..a little chill in the air today, better wear my jumpsuit. thanks again for everyones suggestions and help I really appreciate it. this forum has been a goldmine of info.

This is typical symptoms of a fouled spark plug clearing for a moment before re-fouling.

The NEW plugs should have cured it BUT, you also changed the prop.

Change only ONE THING AT A TIME.

Any more tends to cloud the results and skew the diagnosis.

You haven't mentioned if you have tested compression.

How heavy is your boat, could there be waterlogged foam under the floor?

Reduced top speed can be caused by a number of things, it's just a process of elimination, one at a time.

Retest WOT RPM with the smaller prop to be sure that the ignition is NOT rev limiting, also, any possibility of verifying that tach?

 

[SparkieBoat]

Re: 1996 Rude Power Pack questions

I did do a test run with the new champions before changing the prop..no change..I then changed prop and posted the results. weight is 3080LBS with trailer and ready to go in the water..batteries + anchor + cooler + fuel and other little items. this is the expected weight for this boat, so no water logged foam..McKee Craft uses a closed cell foam that does not adsorb water.
The original tach was reading ok I think, I purchased a new one to check it, just to make sure, the instructions said to set it at the 6P setting which I have done. I have no reason to think the tach is wrong, both tachs are reading the exact same. all of the NGK plugs appeared to be in good condition and they all looked the same.
motor cranks up great and idles very smooth, runs smooth through all speeds but feels like it bogs out just before full throttle. My dad has a 130 johnson on a bigger and heavier boat and it is way more powerful and will out run mine. my motor feels like a 100 hp motor to me. once I get the seals in and the head back on I will test again.
I will also do another compression test..I did compression test when I first got the motor about 2 months ago and they were all with in 10 PSI, I think in between 90 and 100, 5 were real close with one being a little low but within tolerances. If any pictures would help just let me know what you would like a picture of if it would help any.
thanks again for everyone who has taken the time to respond to my post, I really appreciate it. Sparkie

 

[ondarvr]

Re: 1996 Rude Power Pack questions

[qoute] McKee Craft uses a closed cell foam that does not adsorb water.

Not that it matters in this sutuation right now, but there is no such thing, they all absorb water over time.

 

[SparkieBoat]

Re: 1996 Rude Power Pack questions

thats good to know..I did not know that

 

[reeldutch]

Re: 1996 Rude Power Pack questions

what 1/4" seals are you talking about?

the heads have 3 o rings and all the other holes you put a litle black rtv around.
look in the shop manual it will explain it.
make sure the head is absolutely flat.
any slight warp will cause a potential leak.
if your fuel system is good , compression is good, than the only thing that will cause a lack of power is when your timing is off.
check if the timing is indeed advansing. where is it at @ 5200????

 

[SparkieBoat]

Re: 1996 Rude Power Pack questions

roger on the black RVT...got some..timing was 28 BTC at WOT / 5300 RPMs with 19 pitch prop

 

[reeldutch]

Re: 1996 Rude Power Pack questions

wow,

according to my manual a 150 or 175 60* looper max advance timing should be 19-21* btdc.

i dont know exactly what engine you have but 28 * sounds like timing for a old crossflow.

 

[CharlieB]

Re: 1996 Rude Power Pack questions

The condition you are describing is that of an intermittant ignition failure, either of a fouling plug(s), but not because you have just tried the new correct plugs.

OR

An intermittent failure of the ignition system.

As in my first post, have you done ALL the test outlined in the CDI Troubleshooting Manual?

What were the results?

You describe a failure at absollute PEAK load when attenpting to run WOT, yet all seems well at slightly less than peak load. This could be a pack failure, but I doubt it.

It smells more like a stator on the verge of meltdown.

Rig a DVA Meter and go for another test ride checking stator output near and again at, WOT and PROVE if the voltage is beginning to fall off as the misfires begin.

 

[SparkieBoat]

Re: 1996 Rude Power Pack questions

I have not done those test yet..I will have to acquire the tools needed. I will rig a dva meter and see what happens. I would not say that the motor is just fine until near WOT..I would say it seems to lack HP at all ranges, but it is hard to tell, it seems to me to run about like a 100 hp motor. the dva test will help figure it out.
Reeldutch, whatever the timing says on the motor is what it is..I have been working on 4 motors at once so I may have gotten it confused with another motor. But the timing is on my flywheel cover, whatever it says is what it was.
thanks again for all of your helpful responses. I will test if it quits raining tomorrow.

 

[reeldutch]

Re: 1996 Rude Power Pack questions

i would double check it if the timing is indeed advancing and reaching the 20* mark.
if its off that could defenatly cause a lack of power.