Yikes! Something broke, don't know what or how to diagnose!

[dbdave]

Michael

We are all here waiting, watching, and hoping that you will change the spark plugs before you do any other nonsense. Please put any other 3 plugs in your boat, run it, and tell us either they made it work like it should or made no difference. We can't stand the suspense any longer!

 

[crisso]

Micheal,May you please change the plugs.We are asking very,very nicely.At the very least you will have a new set of plugs ready for next time.Please.Half the Seadoo owners of the world have taken bets on this.We are like a roomfull a woman watching "Day's of Our Drearies".Pleeeeezzzzzze.Change them.I wish you all the very best.
Oh KELTONKS Mate.May the force be with you.And NARNU NARNU

 

[dbdave]

Michael, I see you post in other threads but not this one. Have you done anything yet? Just wonderin'.

 

[Coastiejoe]

Killing you to KNOW if the plugs were changed isn't it....

 

[dbdave]

Ya, and I'll bet a few others, too. I'm beginning to wonder..... No, couldn't be.

 

[Michael211_2000]

Michael, I see you post in other threads but not this one. Have you done anything yet? Just wonderin'.

Apologies, with the wildfires breaking out all over my part of Texas (and 1 wildfire broke out in my neighborhood just down the street burning 2 mobile homes and 1 house on blocks), this just has been sitting on the backburner... our freshwater boating season is shot, the lakes and rivers are all bone dry (all the boat ramps are landlocked that I know of). This drought really suxs!

However I did go out earlier this afternoon, pulled each plug 1 at a time and used this shiney new compression tester from O'Reilly's... each cyclinder (holding WOT while cranking 5-6 seconds!) set the guage on exactly 90psi. What is acceptable psi level for the 4TEC engine?

I have not yet swapped the plugs out, I still have the new plugs with 5 hrs on them in the engine.

ps. The ignition spark issue is a non-issue, I just unplugged each coil and set it aside leaving the other 2 cylinders with spark plugs and coils in and hooked up... the open electrical plug on the wiring harness does not spark at all as long as the contacts aren't touching any metal.

- Michael

 

[Michael211_2000]

Micheal,May you please change the plugs.We are asking very,very nicely.At the very least you will have a new set of plugs ready for next time.Please.

LOL! ROF! I appreciate your very polite request. You are very wise I am sure. I haven't touched the RXT in about a month due to all the drought problems going on around here with fires breaking out everywhere friends having to evacuate their homes and the fact that our freshwater boating season is over and done with due to the the lakes and rivers being too low to use now it all just made the RXT engine issue a low low priority. My apologies oh Great One!

I did do the compression test earlier this afternoon and all 3 cylinders had the same psi reading of 90 psi. So I presume this means there is nothing wrong with the head, head gasket or piston's in general?

I can only run it on the trailer now, there is no place I can put the RXT in freshwater to test it at this point... if there's no other ideas I can put last year's spark plugs in and see if it runs any differently on the trailer perhaps? All 3 of my current 5 hr plugs look identical and clean as a whistle though, if there's a failure in 1 of the plugs it'd have to be internal I guess. Is there any way to test the plugs for spark, perhaps pull one of the ignition coils out and put each plug into it 1 at a time and crank the engine? With the other 2 iginition coils disconnected so the engine will not start of course (does holding WOT disable the ignition system or something else to prevent the engine from starting?).

Live long and prosper!

- Michael

 

[Michael211_2000]

Ya, and I'll bet a few others, too. I'm beginning to wonder..... No, couldn't be.

Errrr, wonder what Dave?

We have a severe SEVERE drought going on here in Texas, the last time I took the RXT to the lake was 1st weekend in August I believe and the water around the public boat ramps was barely shin deep... even if the engine hadn't started this sudden missing and surging, there wasn't much chance of doing any more boating with it this year (unless we got like a slow moving tropical storm or something.... which we didn't, we ended up on the bone dry side of TS Lee dangit!). It feels like we are cursed or something around here, we got a few light rain showers this past weekend but it's already dry and dusty around my place again... there was a large mass of rain last night in Central Texas, but it went due South into the Valley, there's another area of widespread rainfall up around Dallas as of this morning but it was sliding due East! The Houston area just cannot catch a break I swear! Houston has been draining Lake Conroe into Lake Houston so Houston's water pumps won't go dry, the rivers all have grass growing on the riverbeds around here and even my stomping grounds up at Lake Livingston you cannot launch a boat at the boat ramps it's so low.

I have a 12 foot deep pond next to my home that I dug with a large excavator machine over a decade ago... it's got like 12 inches of water way down in the bottom of it now, and all the larger fish went belly-up over a month ago and birds are feasting on the smaller perch and catfish now that there's nowhere to hide down there. Ughhhh!

I never even got a chance to take my jetboat out for a run on the lake this year... this drought is a real PITA! Grrrrr!

- Michael

 

[Seadoobuddy]

With 90 PSI it looks like you need a rebuild, surprised it even ran on the trailer, but then there is no load on it either.
Good luck with the weather, maybe you'll get dump on by a couple snow storms from the wicked witch of the West.

 

[Michael211_2000]

With 90 PSI it looks like you need a rebuild, surprised it even ran on the trailer, but then there is no load on it either.
Good luck with the weather, maybe you'll get dump on by a couple snow storms from the wicked witch of the West.

A rebuild? The engine only has 74 hrs on it. What's the psi supposed to be for the cyclinders?

All 3 have the same 90 psi... what could cause all 3 to lose compression all at the exact same time?

Remember this thing was running like a scalded cat for the past 5 hrs of operation, this was the 1st time I took it up past 60mph (was hitting 67-8 mph on the speedo for maybe 45 seconds when the engine suddenly lost all power). This isn't a wear issue, something somewhere failed suddenly. Interestingly is starts right up with just a bump of the Start button still. No coolant loss, no oil loss, no mechanical noises that don't belong.

- Michael

 

[Michael211_2000]

ps. We don't get snow here, maybe an inch of snow once in a blue moon I cannot even remember the last time I saw real snow! LOL! I do not believe for 1 second though that an engine with so few hours has worn out and needs rebuilding, that just does not compute. It may require me to pull it apart to fix whatever has gone wrong, but I have no doubt this is NOT a wear issue by any stretch. The question is what could cause these symptoms on a low hours engine, besides being worn out which it is not!

- Michael

 

[Michael211_2000]

A search of the Forum's reveals that around 150psi is what the 4TEC engine cylinders should be reading. Hmmmm.... this engine is low hours, and was running fine making excellant horsepower right up to the second when it suddenly lost all power which suggests something is broken not worn. At 90psi compression I could not have made anywhere near 70 mph I'd think, so they must have had much higher compression before it lost power. Unfortunately I don't know what the engine compression was before that last 67+ mph run I made with it, so I've nothing to compare the current readings to.

That all 3 cylinders have the same 90psi reading suggests that whatever failed has affected all 3 cylinders, so must be head-gasket or higher up I'd think (ie. not piston or ring related). The head gasket is new as of 69 hrs, and I torqued the new head stretch bolts down myself by the manual in the order the manual specified. No fluid leaks are evident either and fluid levels are all the same as they were before it lost power... so could the head gasket have blown? Would a blown head gasket affect all cylinder's compression at once? How can I test for a blown head gasket? Would spraying soapy water around the head then cranking or running it briefly reveal soap bubbles perhaps?

Thoughts anybody? I'm stumped, but still pondering the problem and where to go from here.

Thanks.

ps. When I replaced the head gasket last fall at 69 hrs (in order to replace a bent connecting rod on piston #1), the walls of all 3 cylinders were like brand new with the factory cross hatching pattern still very sharp and crisp, there was no sign of wear in there just a single bent connecting rod which I replaced... I replaced every stretch bolt and bought all new gaskets, everything is torqued down to the manual specs and I loctite'ed each and every bolt that the manual called for. I cannot imagine why only 5 hrs of operation later all the cylinders would simultaneously lose compression... what might I have done wrong I wonder? Hmmmm......

- Michael

 

[Florida Paul]

I would check the compression tester. All three testing the same sounds suspect to me.

 

[Michael211_2000]

I would check the compression tester. All three testing the same sounds suspect to me.

How? It's brand new and not too complex to use... just the act of unscrewing it from a spark plug hole relieves all the pressure in the guage and it goes back to 0 psi. There is however a little button on the side which when depressed releases all the pressure from the guage as well... it would seem unlikely that it's reading wrong right out of the package.

I say they each hit 90 psi, but #1 cylinder was just a hair under 90 psi maybe 89.5 psi. #2 and #3 however both put the needle spot on on the 90 number. As I said, the cylinder walls were still nicely cross hatched and looked like brand new when I had the head off last Fall to change that #1 piston connecting rod... I cannot see where engine wear should be a factor in this.

- Michael

 

[Michael211_2000]

I've been thinking and thinking since I did that compression test on the cylinders earlier today... and about the only thing that makes sense is if the head bolts have loosened up. I don't know how that could happen, I thread locked them and torqued them down as per the manual (in the correct order and to the correct torque settings and then the additional torque angle on each bolt). It's the only thing that makes sense though, for the compression on all 3 cylinders to have dropped off so suddenly and evenly during that last outting in early August, the head bolts must have loosened up.

Friday evening I'm going to pop the valve cover off and check the head bolts and see how tight they are. They almost have to be loose for it to be running like this and have such low compression on all the cylinders suddenly. But I'm still open to other ideas if you got 'em (pretty sure we can lay the faulty spark plug idea aside though now that we know the compression on all 3 cylinders is so low).

Regards!

- Michael

 

[dbdave]

See my post #76 before you go ripping into the engine, please.

 

[Michael211_2000]

I've already read post #76 before... do you believe that 90 psi is the correct compression for a 4TEC engine's cylinders? Different spark plugs aren't going to change the compression readings on the engine cylinders...

ps. I'm in no rush to rip the engine apart as I won't be able to use the RXT till next year anyhows. (sigh!)

- Michael

 

[crisso]

Did you take the plugs out and crank the engine a bit before doing the comp test.
Have the valves been adjusted since the work you did.Did you have the throttle at wot when you did the test.Was the battery charged to give proper cranking speed when you did the test.HAVE YOU CHANGED THE BLOODY PLUGS YET!:thumbsup:

 

[nb717]

I would check the compression tester . I've had that problem before too. Test it out on an engine you know has good compression before you start tearing apart the engine. I learned the hard way on that one, with a brand new compression tester too.

 

[Michael211_2000]

The bloody spark plugs have NOTHING to do with cylinder compression! If ANYBODY thinks 90 psi is the correct cylinder compression for this 4TEC engine then and ONLY THEN will I be trying a different set of spark plugs. Otherwise there is no point. :toetap05:

I took 1 plug out at a time, installed the compression tester fitting in the plug hole connected the guage and then cranked the engine holding WOT for 5 to 6 seconds and read the guage dial (~90 psi on each cylinder). Obviously by the time I tested the #3 cylinder I had cranked it a bit having tested #2 and #1 previously but the compression was still only 90 psi. Ergo cranking the engine a bit didn't affect cylinder compression, otherwise #3 would have had higher compression than #2 or #1.

I have not touched the valves ever... they only have 74 hrs run time on them just like the rest of the engine. 74 hrs might as well be a brand new engine that's no run time at all hardly. Yes the battery is new and fully charged it turned the engine over at very good speed would have fired right up had I had all 3 spark plugs in and not held WOT. I keep a Battery Tender Jr. on the battery.

Finally please keep in mind that there's no way I could have been going nearly 70 mph with this low low cylinder compression... the cylinder compression had to have dropped very suddenly to cause the engine to lose all power instantly while I was running at high speed that day! This is not a wear or adjustment issue, it stopped running from 1 second to the next losing all power as if the engine had died but as I slowed down to 30 mph the engine was still running just barely and missed and surged the entire way back to the dock. No beeps, no fault codes on the instrument panel. If the valves were this badly out of adjustment I would never have been going nearly 70 mph that afternoon, if the cylinder walls or piston rings were worn out I would never have been doing nearly 70 mph! I lost cylinder compression on all 3 cylinders almost instantly during that last run, there were no mechanical sounds to indicate anything had broken inside the engine it starts easily and idles smoothly even now and it had good horsepower and excellant hole-shot that day just BEFORE I decided to open the throttle up to see how fast it would really go.

Until and unless the cylinder compression issue is resolved, I really do not want to discuss the spark plugs further. :banghead:

The symptom's and the compression readings especially do not point to spark plug issues ya'll. I will check the head bolts for tightness later this afternoon, I'm not saying they have come loose only that loosening head bolts would explain the symptoms I'm seeing here.

If you think I did the compression test wrong please let me know another procedure and I will try it for 1 cylinder and see if I get a different reading. For now though let's stick with the cylinder compression issues, please... thank you! If we get the compression issue resolved and it still doesn't want to run right then I will promptly try my spare set of spark plugs just for grins. Compression 1st though!

- Michael

 

[crisso]

Settle petal
Did you see the post the other day and the guy discovered a broken blower inlet pipe.It sounded a lot like yours.You may have a loose or cracked pipe.His was very hard to see he explained.food for thought?His was from the blower to the inlet.

 

[dbdave]

I give up. Your troubleshooting skills are questionable. You always need to do the easiest, cheapest thing first before you dig into something that may or may not have anything to do with your problem. It's a process of elimination, even if you are sure that what you are doing is not going to make a difference.

The plugs cannot be determined to be bad by life or by just looking at them, and by changing them (the cheapest, easiest, and most probable item) with ones that you know to be good, you will at least eliminate that as the problem rather than tearing the entire engine apart and finding nothing and then coming back to change the plugs. Seems a little bullheaded to me.

Likewise, you are not sure if the compression reading you got is correct or not. The tester may be off, the reading you are getting may be within the acceptable range, you just don't know for sure. The only thing you do know is they are very close in value and not entirely way out of the ballpark. You need to get the actual suspected value for a 4-tech and to make sure what you are reading is correct, try another compression tester before going on a fishing expedition by tearing the engine apart. If you were to have broken or loose head bolts, you most likely would see coolant where it shouldn't be and the compression readings would not be that similar.

Look at the supercharger hose that was suggested, again a cheap and easy possibility that will either be the problem or will be eliminated as a possible cause.

Good luck.

 

[crisso]

Last post here for me.Bye Bye

 

[ocod]

With what I searched for you others say 120...
But I would start by checking every single hose for cracks along SC path. A leak would cause lack in performance.

 

[Kozerxp]

With the compression reading being low but equal I would say the gauge is inaccurate and the compression is ok verify the gauge accuracy first before pulling engine apart I have three compression gauges and all three read different on the same engine u get what u pay for u bought a cheap gauge so is not a great gauge but the equal reading seem ok I also think u might just have a boost leak a tear in a hose or one popped off I would go over and check all the intercooler piping for a Loose clams or ruptures