Engine Detonation

[Cobra Jet Steering LLC]

The last time I heard of a mr1 engine doing that it was caused by low oil from the oil filter leaking at the crimp due to rust.

 

[Ronnie]

@ jetexpress, it sucks that this happened to you especially at the start of the boating season. We just missed each other in that I only recently sold an 06 fx cruiser waverunner with the same engine and a bad Ecu for $1.400. I have had a PWC with a rebuilt sbt motor in it and thought it ran great, the key in my situation was that a qualified shop installed and tuned the engine but look into it some more because one of the sbt requirements is that you turn in a usable core sometimes this means you have to repair the broken part or provide a functioning one. My recommendation is that you test drive and, if it's running right, buy a used fx waverunner preferably from the same year as your boat and replace the damaged engine from your boat with the one from the waverunner. You may be able to do this yourself for under $4,000 (in current Nor Cal PWC prices). Also do somemore research here and/or the other site, yamahajetboaters.com, there are at least two others that had to replace/repair their engines so they may be able to suggest a good shop for you to use or an alternative to my recommendation.

 

[jetexpress]

The last time I heard of a mr1 engine doing that it was caused by low oil from the oil filter leaking at the crimp due to rust.

I replace my oil filters each fall when I change the oil. The oil filters have no rust on them and they were not leaking. I also checked the oil before we went out and the level was right above the low mark on dip stick.

 

[jetexpress]

@ jetexpress, it sucks that this happened to you especially at the start of the boating season. We just missed each other in that I only recently sold an 06 fx cruiser waverunner with the same engine and a bad Ecu for $1.400. I have had a PWC with a rebuilt sbt motor in it and thought it ran great, the key in my situation was that a qualified shop installed and tuned the engine but look into it some more because one of the sbt requirements is that you turn in a usable core sometimes this means you have to repair the broken part or provide a functioning one. My recommendation is that you test drive and, if it's running right, buy a used fx waverunner preferably from the same year as your boat and replace the damaged engine from your boat with the one from the waverunner. You may be able to do this yourself for under $4,000 (in current Nor Cal PWC prices). Also do somemore research here and/or the other site, yamahajetboaters.com, there are at least two others that had to replace/repair their engines so they may be able to suggest a good shop for you to use or an alternative to my recommendation.

Thanks Ronnie, yea I'm still researching my options.

 

[jetexpress]

Well I finally got an answer from the dealer about the engine. It definitely threw a rod. It wiped out both sides of the block, and damaged the cylinder head. I'm going with a remanufactured engine from SBT with a two year warranty . They won't except a core return on the damaged block or cylinder head because they are unrepairable. Also getting a new oil pump assembly because of the possible contamination of metal in the old pump.

 

[skyler baldwin]

Hey guys new to the forum and jet boating, just bought a 2007 sx230 with the mr-1 HOs. One engine was bad at the time of purchase so we are replacing it. Please see my picture. Looks likes the cylinder closest t the oil reserve failed. What would cause the engine to malfunction and this to happen? Trying to figure out so i can prevent this from happening to my replacement.