still wondering about a noise...

[Gorilla0178]

Ok Ive brought this up before, ill try to make it short. I had a powerpack on my 99 200 johnson go bad, it wouldnt run good above 3000rpm, an had a flutter or miss sound if i tried to run faster than that. Bought a new CDI pack and it runs great, but it has this sound throught the exaust still that wasnt there before the pack went bad. I've been running it for a while with no issues yet. If i slowly get up onto plain it makes the noise the whole time, if i slowly accelerate it makes it constantly, the only time it stops is when your hard on the gas, then if you let off a little it comes back. I was told it was running real rich by a mechanic that heard it running recently, but i still think its odd that it happens so much. Everything seems to run fine with it, it idles good, accelerates good, runs up to over 6k rpm, temp is a bit low due to having washers instead of thermostats, comp is good. It doesnt make the noise while on the hose or if i rev it up while its not in gear in the water. Is there anything else that the pack could have messed up when it went bad? I dont notice a loss of perf that I can tell. I just want to track down this noise. I dont know how to describe the noise, kinda soulds like a tazer going off if that makes sense, a snapping or flutter that can be heard through the exaust.

[Riverman]

I'd pull the heads and have a look at the pistons and cylinders first.

[Gorilla0178]

I just had the heads off, i switched them from 3 liter to the 2.7 liter. Everything with the pistons was good. I gained 20 lbs comp and 5 mph. still has the noise. What would i be looking for?

[racer]

First pack sounds like it was going into slow. I would check for a double fire on the new one.

[ChrisCarsonMarine]

Are you using champions or Ngk plugs,cdi packs sometimes run poorly or do strange things with ngk's,use the correct champion,Chris

[Gorilla0178]

The plugs are stock champion plugs. I was told it was the high speed circuit that went bad on the stock pack. When it went bad it only made the noise when i tried to run it hard, below 3k rpm it ran normal. I put the new pack on and it runs good but has this noise all the time unless hard on the gas. It gets annoying while running. My buddy that was with me when it went bad thought it sounded like a miss or short. Now that reminds me, when i investigated it when i got home I found one of the coil wires coming from the pack pinched between the head and the block, the sheath was pinched and it exposed the wire, which I thought was the original prob, but i patched it up and it still didnt work so i got a new pack. If that was grounding out could it have broken anything else. How do I check for a double spark? There are no other symptoms that I know of other than this noise.

I appreciate all the help.

[t4265]

have you checked all the leads, plugs, coils etc for arc. When sparks jmp they give that tazzer sound you described.

[Gorilla0178]

I did while it was on the hose, i just unplugged the wires from the spark plug while it was running, a shocking experiance. All of them were getting good spark. The noise is only while in gear while running. If i rev it on the hose or in the water no noise. In gear running there's noise. Gonna swap the coil that had the pinched wire, and see if that helps.

[Forkin' Crazy]

How do I check for a double spark?

A timing light should work.........

[Riverratt]

A timing light should work.........

I agree. Index the flywheel and mark all 6 cylinders on the flywheel and you will be able to see if any are firing together.

[t4265]

Hi
The way you describe it could still possibly be a spark issue. If i can relate it to you in a basic term. You can have 12 volts in a system but no amps and to the untrained eye you have checked the system for a good 12v supply.... most people stop there. another one... you can turn your water tap on a little bit... you still get water but there is no pressure. What i am trying to say is... you say that the noise is not there when its on the hose or running out the water in gear.... I:E The engine is under no load. everything is working under minimum effort

You described the noise happens when under load and the rpm is climbimg. On conventional ignition systems as the RPM goes up the spark plug requires more KV (kilo volt) from the coil to develop the spark and cause it to jump the gap this is due to the increase in combustion pressures and increase in the fuel volume at higher rpm these both mean more compression and load which in turn requires more KV to produce the spark

Example Engine on idle......... kv required from coil to cause spark to jump the plug gap 8000kv
Engine at 3000RPM..... Kv required from coil to cause spark to jump 25000kv.
On yours It may just be a coil that is breaking down under load. check your plug gaps etc... May sound silly also but run the engine and spray a mist of water over the plugs leads and see if you see sparks jump they generally show them self when wet.

I dont want to send you up the wrong path as some of these forum threads do but i mearly want to give you some thing to think about.

can i also suggest a pair of plastic pliers for removing plug leads lol

Hope this is of some help

[Gorilla0178]

Plastic pliers ha ha ha.... Your info is great, I went out and swapped out the coil that had the pinched wire on it, I won't know if it helped till I run it. Well have to see.

On the coil one of the bolt holes has a metal strap on both sides, I assume it's a ground or something, on the coil I took off the strap was pretty corroded, I don't know if that makes a difference.

[gfinch]

Plastic pliers ha ha ha.... Your info is great, I went out and swapped out the coil that had the pinched wire on it, I won't know if it helped till I run it. Well have to see.

On the coil one of the bolt holes has a metal strap on both sides, I assume it's a ground or something, on the coil I took off the strap was pretty corroded, I don't know if that makes a difference.

I take a set of ignition pliers and attach a wire to them with a wire clamp like used on a battery charger. When the spark jumps it goes to ground through the wire not you The electricity that comes to that single wire that goes to the coil has to go to ground through that metal strap.
The noise you are hearing can be a "Too rich sound= 4 stroaking" and/or a cylinder thats miss firing

[Gorilla0178]

I was told too rich, but I didn't think it was there before the pack went bad.

[gfinch]

Usually the engine sounds dull or flat with a dead hole. With a cylinder cutting in/out you can hear the difference.
I cheat by having a pyro in each cylinder with the display on the dash.

[Gorilla0178]

Usually the engine sounds dull or flat with a dead hole. With a cylinder cutting in/out you can hear the difference.
I cheat by having a pyro in each cylinder with the display on the dash.

How do you have that set up? I would like that.

[gfinch]

2 of these, http://www.racepak.com/F1-C.html
6 hollow head studs
6 pyros with cabling

I told you I cheat, I am blessed to have very knowledgeable and generous friends!

[Gorilla0178]

It was suggested that I get egt gauge, I'm all for knowing what my motors doing. It's on my list of things to do.

Damn I wish my motor looked like that...What are all the extra fittings for, like the one that is In the notch next to the v6 logo, and the one above it, and tapped into the top of each head, boy there are a lot of extra hoses....

What does the pulley off the flywheel run?

Where did you order the hollow head bolts from?

[racer]

Slow keeps the engine right at 3k or so, if the box was fine under 3 it was going into slow. At times they will do that for no reason other than going bad.

[Gorilla0178]

3k was the magic number.....

[Gorilla0178]

So i took it out for a hard run earlier. I swapped the coil out that had the pinched wire on it, i noticed that the ground strap had alot of corrosion on it. I noticed the noise a little bit today but i dont think it was as bad as the other day. i dont know if the coil helped, or maybe the cooler air. I checked the plugs when i got home, i didnt bring the right wrench to do it on the water, and they were all brown, none of them looked like they had water on them or were white. It was running good. It was running cool. It seems to lose the smallest amount of power if you put the pedal all the way down, it seemed to run best just off the bottom. I just adjusted the throttle stop and made sure all the butterflys were totally straight open, they were not opening all the way before.

what exactly is 4 stroking?

[jphii]

Watch this:

<iframe width="853" height="480" src="http://www.youtube.com/embed/0wzph3hL6EE" frameborder="0" allowfullscreen></iframe>

[Gorilla0178]

That's a great video. That is kind of what it sounds like. I'm still going to clean all the coil contacts to seeif that helps. If it turns out to be four stroking how do if fix if or do I even need to?

[gfinch]

Thats a good informative video.

[M. HARDEE]

If the new plugs were in it when pack went bad --may have gas foul some of them -- ---once gas fouled THEY USUALLY never clear themselves completely ---and will get that sputter too rich condition/sound --also ACCATIONALY have seen closing the plug gap up 4 or 5 thousants will take the sputter or a miss out in rare cases--

[Gorilla0178]

Ill get new plugs, they were new when the pack went bad. Plugs still look good, but ya never know. I heard about the gap too, i have them gapped to .30 ill try smaller next time. That will be before the next test run. Gonna make sure that the mid air bleeds are clear too.

[jphii]

You do mean .030, correct? I gap mine at .022.

[Capt.Insane-o]

Check the primer pintle.

[Gorilla0178]

Yes I mean .030, i was wondering about that when i typed it. I'll try a little smaller when I get new plugs. I'll check the primer also to be sure.

[Forkin' Crazy]

Did you change the head gasket on the side you were getting the water on?

[Gorilla0178]

Water? I only noticed a few dropplets on a couple spark plugs after it was sitting for a day or so. I checked the plugs after running it and they all seemed to look ok. I didnt end up changinging the gaskets, I had to reuse the ones I had, they were pretty new to start.

[Gorilla0178]

Well I guess i didnt know it wasnt blown. I went out and did a comp check before i changed spark plugs, 1 was not reading any comp. i took the head off and found a broken fire ring. im pretty sure it happened right after i put the head on, i did a comp check and found that 2 of the bolts hadnt been tightened all the way on that cylinder, so i guess it broke the ring. So i ran it that way and didnt even know it. I dont think it damaged anything, didnt see anything out of the ordinary, im keeping my fingers crossed.

[terry taylor]

I just had the heads off, i switched them from 3 liter to the 2.7 liter. Everything with the pistons was good. I gained 20 lbs comp and 5 mph. still has the noise. What would i be looking for?---------------------And how many rpm,s thanks.

[Gorilla0178]

if i plug in the numbers into the prop slip calc, i think about 400 rpm, i was getting 74 at about 6200, and i got it to 80, which should be at 6600 or so. Thats with a blown fire ring on 1 cylinder, i dont know how much that affected it, but ill post when i get new gaskets.