One of these is NOT like the other - - -

[kaitsdad]

Yep. Started oil consumption during the EODZA - 1 qt - 150 mi. 124K ish on the bike.

Did a compression check today - findings written on the box. #3 jug is just moving air.

Also has a very pronounced rod knock.

Doug's looking for a new engine, perhaps even a bike.

 

[Surly]

Bugger! That is sad.

Hope it gets sorted.

Best regards

Surly

h34r:

 

[beerme]

So sorry to hear this! Glad you're there to help, Hal.

 

[RossKean]

Any chance its just a carboned up valve? I would at least try a good dose of Ringfree and/or Seafoam to see if it helped anything. How many miles? What model year?

 

[Fred W]

+1 to what Ross just posted. Those were my exact thoughts.

Before trashing the engine you will definitely want to know where your compression loss is.

Rod knock is not really corollary with compression loss. But if the carbon buildup on top of the piston dome is enough, you may be knocking there.

What do you have to lose by investigating further?

 

[Falko]

Any chance its just a carboned up valve? I would at least try a good dose of Ringfree and/or Seafoam to see if it helped anything. How many miles? What model year?

I don't think that would explain the oil use though.

 

[RossKean]

Any chance its just a carboned up valve? I would at least try a good dose of Ringfree and/or Seafoam to see if it helped anything. How many miles? What model year?

I don't think that would explain the oil use though.

But a stuck or broken ring might explain this. Same initial remedy - Ringfree, at least to try. Wonder if compression test was repeated after oiling the cylinder?

 

[ionbeam]

+1 to oil in the cylinder and repeat the compression test.

Rod knock usually starts with an alarming RAP RAP on cold start up then goes away. As it gets worse the RAP will last longer. The noise is alarming enough that people take action right away. If it really is coming from the piston/rod area it would be more likely to be piston slap from the skirt knocking on the cylinder wall. The short skirt 2 compression ring pistons are more prone to piston slap.

 

[dcarver]

I have leak down tester available if you want/need, Hal.

 

[kaitsdad]

I have leak down tester available if you want/need, Hal.

Thanks, El Jefe, I appreciate it.

I was planning on using mine if needed, but with 65 psi and the oil consumption, I didn't see the necessity.

 

[kaitsdad]

+1 to oil in the cylinder and repeat the compression test.

Rod knock usually starts with an alarming RAP RAP on cold start up then goes away. As it gets worse the RAP will last longer. The noise is alarming enough that people take action right away. If it really is coming from the piston/rod area it would be more likely to be piston slap from the skirt knocking on the cylinder wall. The short skirt 2 compression ring pistons are more prone to piston slap.

Yep, could be a piston slap, but the noise is steady, doesn't diminish when warm. Considering that the #3 is just being dragged back and forth that could be it - but it really sounds like a rod knock to these old ears. I used a hearing aid (screwdriver in the ear,) and it's heavier at the crank end of the cases. Just kind of a SWAG on that one.

 

[kaitsdad]

Any chance its just a carboned up valve? I would at least try a good dose of Ringfree and/or Seafoam to see if it helped anything. How many miles? What model year?

I don't think that would explain the oil use though.

But a stuck or broken ring might explain this. Same initial remedy - Ringfree, at least to try. Wonder if compression test was repeated after oiling the cylinder?

The symptoms definitely point to a ring, currently running Seafoam through the gas and in the crank. Hoping that it might free things up. Did compression check twice, upon arrival, then after adding Seafoam to top end and letting soak. No difference. Doug will continue to ride the bike for a while in hopes that the additives will free things up.

And one of these days I've gotta figure out the multi-quote function.

 

[RadioHowie]

And one of these days I've gotta figure out the multi-quote function.

Super easy....just go through the entire thread, clicking "MultiQuote" on the posts you want to quoteback.

Once you've selected all the posts you want to quote, click "Add Reply" and there they are.

 

[kaitsdad]

And one of these days I've gotta figure out the multi-quote function.

Super easy....just go through the entire thread, clicking "MultiQuote" on the posts you want to quoteback.

Once you've selected all the posts you want to quote, click "Add Reply" and there they are.

Thanks, Dad. Will do.

 

[Fred W]

I was planning on using mine if needed, but with 65 psi and the oil consumption, I didn't see the necessity.

I'd have guessed that the amount of time and $ to do an entire engine swap would have provided enough motivation for more testing.

If it's just gunked up and leaking rings they could be taken apart and cleaned. Doing a wet compression check will tell you definitively if it's a valve leak or rings. Then you can decide if you want to try disassembling the engine for more invasive investigation.

BTW - 65 psi isn't just pushing air. There is still some compression there, just not much. And the fact that it is in just one cylinder is kind of a good sign. Probably not a cracked block like Carver's.

 

[RossKean]

A slightly sticky or worn ring will be obvious with an oiled compression test. Maybe not so much with a broken or severly stuck ring. I would run the additives and see if there is ANY improvement - I think Ringfree might be more effective than Seafoam. Still may have a major disassembly to do in the near future. Hope its something simple (i.e. cheap). I don't like hearing about FJR engine failures. Seems to be a bit of a rash of them lately. I see from the title its an '06 but how many miles on it?

Good LUCK!!

Ross

 

[RadioHowie]

I see from the title its an '06 but how many miles on it?

124K ish on the bike.

Example of MultiQuote and Snip.

 

[RossKean]

I see from the title its an '06 but how many miles on it?

124K ish on the bike.

Example of MultiQuote and Snip.

Oops - missed the mileage reference earlier!

 

[yamafitter]

If you can borrow or rent a boroscope that will fit down the spark plug hole it might be worth a look without having to tear anything apart. If you see lots of wall scoring on the cylinder wall then you have either a broken ring, a broken wrist pin clip or a broken piston. If in fact the noise is from the crank end then it is probably a rod issue that in turn caused a ring failure. The only way to get the kind of oil consumption you are seeing is either a cracked piston or a stuck / broken ring. At 124k miles the engine will be kind of tired and will probably need to be completely refreshed with new bearings (mains, rod big ends & wrist pins) along with a valve job to clean up the seats. If you don't have the ability to do most of this work yourself (valves should be done by a pro) it would not be cost effective to go this route.

At that point you would probably be better off to find a low mileage motor or part the bike out and look for another scooter.

I would add the caveat that this is only an opinion of a shady tree mechanic and most of my experience (+35 years) is with 2 stroke dirt bike motors.