Good and bad news

Finally got off my ass and put the motorcycle back together. The good news is it started and ran without making any death noises. The bad news is I still have a problem. 

I should probably catch everybody up on whats been happening.  Some time ago I started the bike up headed to work like always. As I was putting my gloves and helmet on the idle changed and I heard a metallic clanking noise. I gave it a couple revs and didn't like the sound so I shut it off and pushed it back into the garage. The Cam Chain Tensioner is known to be faulty on these models and Yamaha has a revised part. I asked the dealership about it when I bought the bike and they said it hadn't been changed on this one and they can't change it without it making a noise. I was pretty sure the noise I heard was chain slap from a  failed CCT. The next day I trailered it to the dealership explained what happened. My assumption was that they would start it up, hear the chain slap, install the revised CCT and I'd be on my way. They called a little while later saying it wouldn't start said it was making a broken internally noise and wanted another $100 to start taking it apart. I declined and picked the bke up the next day. The dealership had drained the oil.

I got it home and pulled it apart. I did  a leakdown test  which showed 17% across all three cylinders. A little high but it had been sitting with no oil in it for about a month at that point. I checked the cam timing which was still correct. I checked the valve lash which showed several of the intake and exhaust valves to be slightly tighter than spec and several that were right in spec. That needs addressed but I decided to put a new manual adjustable CCT in and try to start it. Turning the engine by hand revealed no metal on metal sounds. But I wanted to turn it over just to make sure because the dealership did a pretty good job of convincing me the engine was probably junk. 

So yesterday I installed the new CCT adjusted it and gave it a go.  Here are the first and second starts. 

https://youtu.be/Y3_xDQjJSTk

Unfortunately I forgot that I had loosened the fuel rail bolts and they didn't get tightened before I put it all back together. That resulted in the fuel injector o-rings being blown apart on my first test ride around the block. With that addressed I was hopeful that it would start and run fine after that. It still is hard to start and although it will idle and rev fine with no load on it, it bogs when under a load. Roll on throttle in sixth at about 3000rpm and it'll start to accelerate then bog slightly a for a bout 500 rpms then smooth out.  And the exhaust stinks

I'm getting ready  to pull it back apart and do a compression test now that I know pistons aren't hitting valves. If that comes back okay the next step is setting the valve lash. I'm a little intimidated by that as I've never had to do a shim under bucket adjustment. I tried to talk the wife into letting me take it to a shop for that but she convinced me we don't have the money. Maybe I'll have it running by spring time. 

Could be too fat or too lean, but sounds like a mixture problem.  Make sure you have no intake leaks, including the injectors.  Do the carb cleaner trick around the whole intake.

Shim under bucket:  Measure everything. Write it all out well organized.  Like 1 intake 1 0.006, 1 intake 2 0.009, etc.  Then pull the cams and put the existing shims and buckets in something like an ice cube tray that you labeled with a sharpie.  Label each bucket with the sharpie.  Measure each shim and record it.  Do the maffs on each shim.  For example, if your target is .006 and the 1 intake 2 valve shim is 40 thousandths thick, then .009 (observed) - .006 = .003, which is how much thicker your shim needs to be, + .040 = .043 target shim thickness.  Make your chart of what you need at each valve.  Look at your shim collection and put the ones that fit that you have in the correct location of your ice cube tray.  If you have a shim that is maybe 1 or 2 thousandths too thick, you can take that off with some fine grinding compound and a piece of glass.  Buy the shims you need. Put it back together. Sell the bike and get another Sportster.  They are cheap in the winter.

Compression is way down on all cylinders.  70 on 1 and 3 dry and wet, 2 was 60 dry and 65 wet. 

This is a concern because the valve clearance on #2 was in spec. 1 and 3 were a little tight. 

I guess the next step is to get the valve clearances in spec then check again. 

I dunno.  That don't sound good.  What is the spec on compression?  What's a new motor cost on ebay?

In reply to Dr. Hess :

Min 189 max 243.

The head is gonna have to come off.  Probably burnt valves.

I am with Dr. Hess, burnt or bent valves.

I still think I'll set the valve clearance then recheck the compression before I pull the head off. 

I don't understand how my valves are burnt with only 10K on the bike when the majority are reporting that valve clearances are still in spec at the 26K service interval. 

Just my luck I guess.

What kind of bike is it?  I thought you had a Harley.

A used motor is two large on ebay.  That sucks.  A used 883 is like $1500 if you shop some.  Here's one for the same price as a used yamaha motor:

https://austin.craigslist.org/mcy/d/georgetown-1990-harley-sportster-883/6751813000.html

Looks fixable.  Just sayin'.

In reply to spitfirebill :

It's a 2015 Yamaha FJ-09. I bought it in 2016, it was a demo bike which may explain why I'm having this trouble. I've used it daily to commute back and fourth to work and a couple weekend day trips. It's got 10,200 miles on it and has been a paperweight for two months.

In reply to Dr. Hess :

The only reason I ended up with a different bike in the first place is that the Sportster doesn't fit me. I've got way too much legs. Anything over 40 minutes and I was in pain. Even with the Mustang touring seat my knees were above my hips. I'd love another Sportster as a second bike. But not for my primary mode of transport. 

OK.  You do need to fit on whatever you ride.  Forward controls?  Nice Evo dresser?  If you want comfy riding, an Evo dresser is the way to go, and they are fairly reasonable.  You can get a nice one for about 2 of those yamaha motors.  Anyway, bummer on the motor problems on a virtually new bike.  I wonder if the timing chain tensioner didn't go out and slightly bend some valves, although that would show by having too much clearance, not too little.  Too little clearance leads to burnt valves.

Is this a drive by wire throttle? If so, did you have a procedure to follow to hold the throttle open while cranking for the compression test? Guessing the computer won't hold the butterflies WFO during cranking no matter what you do with the throttle.

In reply to Ransom :

I unplugged the TPS and manually held it open. 

I'm debating between just pulling the head to see what's up or setting the valve lash first then rechecking the compression. 

Maybe I should just go ahead and pull the head.

In reply to Nick Comstock :

I'm sorry, that blows. Given the equally poor number on the in-spec cylinder and how involved setting lash is, I wouldn't blame you for going straight to opening it up.

https://www.reddit.com/r/FZ09/comments/7udd2d/mtfz09_engine_failure_compression_down/

Get a leak down test or make one out of a spark plug and some pipe. it doesn't need to be air tight.  this will tell you was going where.   the 10mm threads size can be a pain to find adapters for but they are out there.  you may be able to use your compression tester

Man, that sucks... 

I still think the failure started with the CCT, and I think that dealer really berkeleyed you over.  My dealer wasn't much better.  When I first approached them about the problem, they were clueless, and refused to do anything preventative under warranty.  

I hate to see this because it's a great bike and a great engine, except for the CCT.  What's worse is Yamaha knows it's a problem, and refuses to fix it unless it "makes noise", which in your case was too late.   

I hope you don't find too much wrong when you get it torn down and are back on the road soon...

44Dwarf said:

Get a leak down test or make one out of a spark plug and some pipe. it doesn't need to be air tight.  this will tell you was going where.   the 10mm threads size can be a pain to find adapters for but they are out there.  you may be able to use your compression tester

 

I've done a leakdown test. All cylinders at 17% which while on the high side the engine had been sitting for a month without oil so I decided to put it back together and see if it would start. Which lead us to here. I couldn't hear any leakage coming from the throttle bodies or exhaust. I could only hear a tiny bit in the crankcase but no more than what I would typically expect to hear getting past the rings. 

Rodan said:

Man, that sucks... 

I still think the failure started with the CCT, and I think that dealer really berkeleyed you over.  My dealer wasn't much better.  When I first approached them about the problem, they were clueless, and refused to do anything preventative under warranty.  

I hate to see this because it's a great bike and a great engine, except for the CCT.  What's worse is Yamaha knows it's a problem, and refuses to fix it unless it "makes noise", which in your case was too late.   

I hope you don't find too much wrong when you get it torn down and are back on the road soon...

I should have went ahead and put a manual CCT in after I bought it. It was a known issue but I thought it would just make noise for a little while before any damage was done. Live and learn I guess.

I know the head was redesigned for '17 and I've heard an earlier head is unobtanium. I sincerely hope the head isn't damaged.

Anything can be fixed, if you try hard enough or throw enough money at it.  Even a bad head.  You do have to find a good machine shop.  I knew one in Bryan, but they are out of business now.  They fixed my Lotus Twin Cam head, which was cracked in 3 places.  They ground the cracks down, then filled them back in with TIG.   A repair of your head will probably be cheaper than a new used motor, certainly.  But I think your best fix is to buy a new used motor and put that manual timing chain thing on it.  Your leak down pointed to bad rings, not valves.  The compression test pointed to bad valves, not rings.  Weird.

I've been rethinking this. I'm not sure that the bike would start, run and rev the way it did if the compression was actually 100 psi below spec. 

I'm not so sure I need to pull the head right away. I'm going to recheck some things.

I decided to check for any vacuum leaks I didn't find any but did take the opportunity to get a hot start video. 

So here is that. https://youtu.be/yasnSICapSw

Aside from a little choppiness at the very beginning and when the idle jumped up on its own for a couple seconds everything seems to be as it always was. The idle seems steady, revs are free and crisp. 

It's just not presenting as an engine that has extremely low compression or burnt valves. To me at least. 

So, no "broken internally" noises as reported by the dealer in your OP?

That's good news, but doesn't say much about the dealer, though we mostly surmised that already... 

Have you tried another compression gage?

Before digging too deep, I would recheck compression with another gage to see if the readings are repeatable.