engine quit at WOT!!!!!

[yelah]

I was boating along sat. for about 45min and all of a sudden i heard the starboard engine just quit all together. When i went to start it back up, the starter made a growling noise and the engine wouldn't turn over. I tried it several more times out of shear panic with the same resulting screech. I took a deep breath...... and limped back to a calmer area with the port engine. I proceeded to remove the spark plugs and try turning the engine by hand. I found it was very stuck, it wouldn't budge. I then tried the starter again, it turned over slowly at first then after a few more seconds it started to sound normalish. After all that, i was angry. I just made way for the dock and put the boat on the trailer. Waited till today to even touch it. I checked spark, got good spark. Checked fuel, got good fuel. Checked spark plugs, installed new spark plugs. Checked compression, 110psi and 112psi. I sprayed a little WD40 in when i changed the plugs out and it ran for a few seconds...not sure what that means yet. I also checked my fuel delivery by swaping the external fuel pumps. well, that leaves me with the last thing i noticed. When i was hitting the start button and the engine was turning over i saw a little smoke coming from the intake box. I removed the cover and saw the smoke was coming from the carb. I also noticed when i removed the spark plugs that same kinda smoke come from inside the combustion chamber. Im starting to catch on here and i would like to know more about the rotary valve part of this engine. Does it have a "saftey" gear that can shear off? If it does, what happens when that happens? This is a newly rebuilt engine by a reputable company(they both are). I haven't run them very long at all, like 1 hour or so. Im trying to break them in right and this was my first quick burst to full throttle. Surly thats not the problem..right? sorry this is so long.

 

[timmyboy76]

quik burst during break-in...not at all, stud. When I rebuilt my motor on my first Sportster (14ft), after I got passed the wakezone, it was all WOT..from there, bro.
The RV assy, has whats called a brass gear, for this/that reason. If something is to get in the assy, then it'll strip that gear, thus sav'n the crank/rest of motor. Possible, that the rebuild, didnt give enuf clearance for pistons?, but it does sound as if, you'll need to pull that motor out, and break it all down.

 

[seadoodude1]

Something internal broke or the pistons seized since you could not turn motor by hand or with starter after it quit running. Did you fix the problem that caused you to have to rebuild the engines in the first place? And what kind of damage did the first motors have? Were the carbs rebuilt before installing them on the rebuilt engines? If not, my guess is your running lean and burnt up the top of the pistons or may have seized due to lack of oil, but I assume you are adding extra break in oil to the gas so that is probably not the problem. Compression sounds low for a new engine so I suspect some piston damage has occured.

 

[PWCdoc]

I'm willing to bet the brass RV gear sheared away. And judging by those compression numbers I'd almost be willing to bet the motors were rebuilt by SBT perhaps?

But there is a chance you sucked something up into your pump too.

 

[Chester]

I think you had a major engine failure. It's time to make use of the warranty with the "reputable company". Whatever you do, don't take the engine apart as this will void the warranty.

Chester

 

[yelah]

when rebuilding i found it has been sitting for 5 years and everything was locked up. i also found a bad oil pump, so i replaced it with a good one. im going to take my video bore scope and stick it down the carb and see if the rotary vavle turns when i start it. then i'll call and use that warr. i have. I'll let you know what i find tonight.

 

[yelah]

Well, here are my findings. I removed the airbox and stuck my video bore scope down the carb throt and cranked the engine a little. I found the engine would run a little but the rotary valve wouldn't turn at all. I called the company i got the engine from and they were very nice and said i should take it out and ship it to them and they would take care of it. is this a common faliure? Are these rotax engines good for the long haul?

 

[PWCdoc]

What company rebuilt the engine?

 

[yelah]

The company i got my engines from is East Coast Seadoo. They are in Bensalem PA. The guy i talked to and have been dealing with is awesome, his name is Tom. The number there is 215-639-0988. He cut me a deal if i got both engines at the same time. I paid $650 ea. with a 1 yeah warr. on the engines. I'll let you know how the warr. claim goes.

 

[yelah]

Just an update - I shipped my engine out to have them take a look at it (cause it is under warranty). I called to see if they got it ok, and they said that they did and it is already being taken apart and repaired. Doesn't look like i'll have to pay for anything except the shipping there ($14.00). I'll let ya know when i get it back what happens. The weather is nice here and im freaking out!:ack:

 

[seadoosnipe]

Rotary...?

What kind of oil are you using in your rotary bath?

If these engines were just rebuilt, something had to cause that woodruff key to shear. It's not usual for this to happen after such a fresh rebuild.

I'll be installing my 12 SBT engine this coming week and I've never had that type failure. I''ve used their 657, 717 and 787's with great success. The only problem I've ever encountered was a leaking gasket at the head of the 717.

The price for your engines sounds great. It sounds like you have a nice company to work with too. So, when you get it back, see if you can get his opinion on the root cause as to why this happened. You can tell him, we ALL want to know. Especially after you gave him a free plug!.....:rofl::cheers:

 

[yelah]

quicksilver synthetic pwc oil. im running the same thing in both engines. I have had only one fuel related problem with the other engine. i'll call later this week and see what they found. he did ask me to send my rotary plate cover this time to check the clearances. he also said it could be crankshaft alignment. he said he would check all that too.

 

[timmyboy76]

crankshaft alignment...

might be a "tard" for post'n this, but...thought the crank sits in the cases, one way..

 

[yelah]

Well, i talked to my guy at East Coast Seadoo. He said that the brass gear just let go and hes not sure why. he thinks it might have just been a defective part. he said this is the first he has seen of this condition. There didn't seem to be any indication of anything entering foreign entering the engine and it had plenty of oil (no burning marks) the only thing he said was that the rotary valve clearance could be too tight (my fault i didn't check that). Se he is going to put it all back together and check and if need be adjust the rotary valve clearance. Man, these guys are a pleasure to deal with. my out of pocket cost :$14.57 for shipping. It going to be shipped back (on there dollar) Friday. Anyone have a theory on what "might" have happened? just curious.

 

[timmyboy76]

with clearance related, installed the wrong o-ring around the RV assy...looks just like one, of the top-end o-ring...?

 

[yelah]

The problem,..and the fix!!!

So i finally found out what was wrong with the engine that failed. East Coast seadoo took the engine apart and found nothing at first and just thought that the problem was a inferior brass gear on the rotary shaft. They reassembled the engine and thought everything was good, before shipping my man Tom thought it a good idea to spin it up on a machine they have to 3000rpm, good thing he did. He found that the gear was getting chewed up again. He found that the rotary valve shaft was bent. Long story short, he replaced the shaft tested it again and it on its way back to me. Thanks Tom. Im very happy with the service at East Coast Seadoo. My out of pocket cost was $14.00 for shipping.

 

[TVZ1965]

WOW Lets hear it for aome great CUSTOMER SERVICE. It not often we hear of it. OH wait maybe it just me.:hurray::cheers: