Yamaha 1.8L TBO

[FLJetBoater]

Does Yamaha publish a TBO (time between overhauls) on the 1.8L engines? Specifically the post-2015 timing belt version.

 

[bikerman5345]

No they do not. Its not an aircraft that will fall out of the sky so no need for a TBO. When it breaks you fix it. When you notice performance loss you diagnose and go from there. No reason to just overhaul the engine at a specific time. But these engines with proper maintenance are known to go over 1k hours.

 

[FLJetBoater]

No they do not. Its not an aircraft that will fall out of the sky so no need for a TBO. When it breaks you fix it. When you notice performance loss you diagnose and go from there. No reason to just overhaul the engine at a specific time. But these engines with proper maintenance are known to go over 1k hours.

Thanks. I was curious because we have 1100 hours on ours and looking to sell it. Wanted an idea of how much life is still in them.

 

[bikerman5345]

You can do a compression check and borescope the cylinders, you can also remove the Valve cover to inspect the cams. Then you can take an oil sample and send it out to see what wear metals show up. Doing all that should give you a good idea how the engine is doing.

 

[adrianp89]

The rental skis for 1000s of hours. I’d be more concerned about sand that has been sucked up and starting to clog jackets.

 

[FLJetBoater]

You can do a compression check and borescope the cylinders, you can also remove the Valve cover to inspect the cams. Then you can take an oil sample and send it out to see what wear metals show up. Doing all that should give you a good idea how the engine is doing.

I plan to do a comp test when I change the plugs next week.
Speaking of which - on the SE with push button start you can’t really control how long it cranks for. Do you just let it run it’s course? Also, is there a way to cut fuel without cutting ignition? I know on the earlier models you could just pull the kill cord and still crank. But on these pulling the kill cord kills the starter entirely

 

[FLJetBoater]

The rental skis for 1000s of hours. I’d be more concerned about sand that has been sucked up and starting to clog jackets.

Well it’s my boat so I’m fairly certain there’s not been much sand sucked up. But, what’s a jacket?

 

[FSH 210 Sport]

The rental skis for 1000s of hours. I’d be more concerned about sand that has been sucked up and starting to clog jackets.

I know I read / hear about rental skis regularly going for over 4000 hours.

 

[bikerman5345]

Well it’s my boat so I’m fairly certain there’s not been much sand sucked up. But, what’s a jacket?

The water jackets are around the cylinders. What happens is the sand gets sucked up and then accumulates in those jackets at the bottom. This hardens up and prevents water from cooling the cylinders. Over time its not good and the only way to really clean those is engine disassembly. You can actually pull the anodes in the engine and stick a borescope in there and see how much is around the cylinders.

 

[Farny]

I plan to do a comp test when I change the plugs next week.
Speaking of which - on the SE with push button start you can’t really control how long it cranks for. Do you just let it run it’s course? Also, is there a way to cut fuel without cutting ignition? I know on the earlier models you could just pull the kill cord and still crank. But on these pulling the kill cord kills the starter entirely

Unplug all your injectors if you’re talking about a compression test. With push button you can crank a few times if needed to get your readings. Yamaha dealer said leak down is better test for these engines than compression.

 

[TommyMcK]

As mentioned above, these aren't airplanes, but that guidance isn't a bad starting point for setting general expectations, for planning purposes, on life for an engine that sees episodically sporadic use. That is typically 2000 hours and someplace between 12 and 20 calendar years independent of hours for aviation engines. Plenty of pilots ignore the calendar recommendation and more than a few ignore the hour recommendation so long as they aren't flying for hire.

 

[FSH 210 Sport]

There are actually two tests you can do with the oil system to keep an eye / trend on what’s happening in your engine.

You can do the aforementioned used oil analysis, as well as doing a filter patch test. The latter is where you use a specialized tool (like a tubing cutter) to open up your oil filter (without putting pieces of metal in the filter) and send that along with the UOA sample and the lab will tell you what’s up with your engine.

Barring any dramatic engine problems, oil usage will start to trend up between changes as the engine starts to get some significant wear.

 

[FLJetBoater]

Unplug all your injectors if you’re talking about a compression test. With push button you can crank a few times if needed to get your readings. Yamaha dealer said leak down is better test for these engines than compression.

thanks. That makes sense! Do you need a professional to do a leak down test?

 

[bikerman5345]

You need a special gauge set to do a leak down test and an air compressor. You move the cylinder you want to check to top dead center. Pressurize the cylinder to 80 psi and the other gauge on the differential tester will show you the maintained pressure. You can also listen for air escaping out the intake or exhaust or even air coming out of the crankcase breather for blowby. You want to be as close to 80 on the other gauge as possible which means you have a good cylinder seal on the rings and valves. Its more involved than a simple compression test so i would recommend just doing a simple compression test first. That will tell you quite a bit about the health of your engine.

 

[FLJetBoater]

You need a special gauge set to do a leak down test and an air compressor. You move the cylinder you want to check to top dead center. Pressurize the cylinder to 80 psi and the other gauge on the differential tester will show you the maintained pressure. You can also listen for air escaping out the intake or exhaust or even air coming out of the crankcase breather for blowby. You want to be as close to 80 on the other gauge as possible which means you have a good cylinder seal on the rings and valves. Its more involved than a simple compression test so i would recommend just doing a simple compression test first. That will tell you quite a bit about the health of your engine.

Thanks! I’ll do the compression test first and go from there

 

[Farny]

thanks. That makes sense! Do you need a professional to do a leak down test?

What @bikerman5345 said?