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View Full Version : 93 Mastercraft 190 25th Anniversary model


Clark
07-05-2007, 02:42 AM
my boat is making a popping noise when in gear and under acceleration. it is a consistent noise that goes away once throttle is backed off. seems to lessen as motor warms up although always present. noise is only present when under power in gear.
Any ideas of the source? clark.mcfadden@cusl.com

east tx skier
07-05-2007, 12:04 PM
How loud is it? Check to see that all of your plug wires are connected properly. Had this happen to me on our first outing this year. Very disconcerting (loud) pop sound.

Clark
07-05-2007, 01:34 PM
Thanks. i have checked and double checked all plugs and plug wires. all are good.

André
07-05-2007, 01:41 PM
Thanks. i have checked and double checked all plugs and plug wires. all are good.
Could it be coming from the tranny?

Clark
07-05-2007, 03:23 PM
i do not believe the sound is coming from the tranny. it is at the top of the motor somewhere. starting to think it is exhaust related.

dchatagnon
07-05-2007, 03:53 PM
Is it a "ticking" noise ? if so, check if you don't have an exhaust leak between the exaust manifod and your cylinder heads.

Hoosier Bob
07-06-2007, 12:26 AM
Check to see if it is coming from the spark arrestor. Could be a weak valve spring allowing compression to shoot back through. Could be worse as well and be worn rings/cylinder. This allows pressure to hit the crankcase and eject through the PCV valve I believe. First check the springs. They sit compressed for a long while and typically on the same cylinder. Weak and or broken springs can cause a "flutter" in the accelleration and an open intake valve can cause the sound you are hearing. If the boat is running perfectly disregard.:o

Clark
07-06-2007, 12:28 AM
Hoosier Bob, Thanks for the advice. Compression is 200 in all cylinders which tells me engine is 100%.

JKTX21
07-06-2007, 12:33 AM
200!! That seems high to me. My boat runs fairly decent with compression ranging from 120-150 (have a couple of leaky valves).

Hoosier Bob
07-06-2007, 12:39 AM
Should it not be in the 130 range?:confused: How does she run?

Clark
07-06-2007, 02:44 AM
it has the LT1 Corvette block and is rated to be at 200.

just advised that the noise is related to electronic engine octane management. popping sound is as a result of module being defective. will confirm and advise.

Clark
07-06-2007, 02:59 PM
200 is what it is rated for. Boat has LT1 Corvette motor.
Was told to check module that warns of low octane..... advised that it may be defective. Search continues...

mcwakebder
03-30-2009, 11:51 PM
I just put my 1997 Ps 205 in the water and the second day we had it out I had the same symptoms. Was there ever a resolution to this issue? I checked plugs, transmission fluid was a little low. Would that cause it?

barefoot
03-31-2009, 01:31 PM
My understanding of compression is that it will drop over time with use. What you are looking for is a constant drop in all cylinders in a tight range. What you don't want to see is a cylinder with 105 and another with 150.

EricB
03-31-2009, 02:22 PM
Does it "pop" only under hard acceleration? Does it stop when cruising at 30~35 mph? Will it start to pop when you go wide open throttle? Does the boat seem to miss-fire when it is popping?

EricB
03-31-2009, 02:24 PM
and additionally, will it pop only when warm? Will it pop when it's cold? (this would require letting the engine cool and trying it cold).

mcwakebder
04-05-2009, 09:26 AM
Those are all the symptoms for my boat. We can not tell where the popping is coming from. It is not the lifters. It sounds lower. It pops when getting on a plane and over ~25mph. If anyone has had the same problem I would love to know that I am dealing with.

BrandonKTM
04-08-2009, 11:49 AM
Those are all the symptoms for my boat. We can not tell where the popping is coming from. It is not the lifters. It sounds lower. It pops when getting on a plane and over ~25mph. If anyone has had the same problem I would love to know that I am dealing with.

Check your plug wires and the firing order. Believe it or not, the engine can still run if you have switched two plug wires. Had it happen on a Ford tractor when I replaced the wires and it started, ran etc but I guess it had to do with how the fuel was being burnt in the wrong order and thus wrong ratios, it sounded like popping, and it changed with different amounts of throttle....

mcwakebder
04-15-2009, 08:52 PM
It turns out it was a bad cylinder or cylinder rod? We are getting a new Indmar 350 engine for the 1997 model for a pretty good deal. Should be back on the water in a couple days. I always heard that was the cadillac northstar engine but I am not sure if that is correct. I know its a GM block.

TMCNo1
04-15-2009, 09:08 PM
It turns out it was a bad cylinder or cylinder rod? We are getting a new Indmar 350 engine for the 1997 model for a pretty good deal. Should be back on the water in a couple days. I always heard that was the cadillac northstar engine but I am not sure if that is correct. I know its a GM block.

Probably a 350 with the Northstar ignition IIRC.