Valve Check Problem!

[RossKean]

This isn't the first valve check and adjustment I have done although it is the first I have done on my 2011.  Never had any problems in the past with my '07.

About 130,000 km on the bike (81,000 miles).  Last check was done by previous owner at ~26,000 miles.

All exhaust valves were OK.  Most of the intakes were right around the minimum (0.15-0.17 mm) but one (4-2) was closer to 0.12.  With shim swapping, sanding a few and replacing two, I got everything in the range of 0.18 to 0.21 mm.  Buttoned it up and today I added coolant and changed sparkplugs and decided to fire it up for a leak check.

Started very easily and did the normal fast idle.  After it warmed up, the idle dropped a bit too low so I kept it running by applying a bit of throttle.  As it got warmer (about mid scale), the engine started to bog down - almost like a cylinder was dropping out or running out of gas.  Ran really crappy so I shut it down.  It restarted just fine after a few minutes and ran for a minute or so before it started to bog down again.

No pinch in fuel line, tank venting properly, engine not overheated (based on temperature gauge).  No codes came up on the dash although I haven't checked history yet.

I thought I was being really careful with cam timing.  I zip-tied the chain to the cam sprockets and just moved the intake cam aside rather than removing it.  Never had an issue doing it this way before.

Any ideas for me other than to take it all apart and see if I somehow managed to mess up valve timing?  Would that cause it to run just fine cold but bog down when the engine heated up?

 

[Fred W]

What else did you do besides the valve check?  Specifically, did you replace the plugs?  Reason I asked is because I generally do that.  Using the principle of suspecting the MRFWU (Most Recently F***ed With Unit) it might be a bad plug.  Even new parts go bad sometimes.

 

[RossKean]

What else did you do besides the valve check?  Specifically, did you replace the plugs?  Reason I asked is because I generally do that.  Using the principle of suspecting the MRFWU (Most Recently F***ed With Unit) it might be a bad plug.  Even new parts go bad sometimes.

Yes, I did change the plugs.  Standard NGK CR8E.  Never had a bad one before but maybe I'll toss the old ones back in.  They were CR8EIX Iridiums.

Thanks for the suggestion.

 

[Fred W]

A lot easier than pulling the valve cover again, right?  Watch out for a loose cap to wire connection while you’re at it.  Hope that’s it.

 

[RossKean]

I don't think it is a loose cap.  I wiggled them around a bit when it was running poorly and it didn't make a difference.  Pretty sure the TBS is way off but I don't think it could be that bad - especially not when holding the throttle open.

Cam timing wouldn't do this, would it?

 

[RossKean]

Swapped the old plugs back in and I am still having issues.  Starts very easily and runs fine until the cold idle goes to normal.  Engine starts to bog at one or two bars on the temperature gauge.  I kept it running at around 1200 rpm until it was fully warmed up - 5 bars or mid-scale for a Gen II.  After that temperature, I really had to play with the throttle to keep it going.  I shut it off in case something was going on that might cause damage.

Could a TBS that is off by a lot have this effect? (I wouldn't expect so)  It was running well before the valve check.  I noticed one torn sync port rubber cover and replaced it.  I have not done the TBS yet.  I was thinking about doing a throttle body cleaning and wasn't going to do the TBS until after.

Would a cam timing issue cause this?  Don't know how it could happen but anything is possible, I guess.

Engine seems to rev OK but can't really tell if power is off without buttoning it back up for a ride.

Pretty sure valve clearances are OK - ran it through two cycles and nothing below 0.18 and I had one at 0.21 which is close to the maximum.

 

[RossKean]

Playing with it some more. Used the throttle lock to keep it running at around 1200 RPM after initial warmup. It actually stayed pretty steady as long as I let it run (~10 minutes). Responded decently to throttle. Fans came on and cycled normally. As soon as I let off the throttle, it died immediately. Idle speed adjustment didn't really help. I checked and wiggled every electrical connection while it was running and nothing made any difference. I did notice that every couple of minutes, I would get a "stumble" in the idle but that isn't abnormal for an FJR.

Start with a TBS with air screws 1 turn out from fully seated as a starting point?

I don't really want to tear it apart again unless there is a reasonable chance that these symptoms are caused by a cam timing error. Can't imagine it has anything to do with valve clearances - I couldn't have messed it up that badly.

One more question - do you route the throttle cables over or under the coolant pipe? Can't remember what they were on my '07 but they were under the pipe on this one.

 

[Mozey]

Can you check exhaust temperatures to see if one cylinder stops firing when the engine heats up?

 

[Goodman4]

You've certainly got my sympathy that you are having trouble with this, Ross. I'm following the thread to learn.

 

[RossKean]

Can you check exhaust temperatures to see if one cylinder stops firing when the engine heats up?

Good thought.  I just started it up and let it warm up for several minutes and checked the pipes with an infrared thermometer.  Hard to get a stable reading and the exact spot seems to make a difference but I did not see huge differences between the four pipes.  Outside pipes maybe a few degrees cooler but probably just from more air circulation.  

Trying to find out what symptoms might be expected for a skipped timing tooth.  I have read that power will be down but haven't found (yet) that idle (post cold idle) could be dramatically affected.  Not all together so I can't take it for a ride.

Not looking forward to tearing it apart again to verify the timing.  Really hard to see.

 

[RossKean]

Summary...

2011 FJR second valve check @ 81,000 miles.  (no adjustments the first check).

Exhaust valves OK, intakes were mostly around 0.15-0.16mm but one was 0.12mm so I adjusted all to 0.18 to 0.21mm.  Checked all clearances twice taking the engine through (at least) one complete combustion cycle using a wrench on the crank.

Starts very easily and throttle response seems good.  (Have not finished assembly so I couldn't ride it to check power.)

Cold idle approx 1,300 or so which is where it was before.

Engine bogs and stalls when it comes off cold idle (I previously had warm idle set around 1100 rpm).  Idle speed adjust doesn't really help. Will run smoothly with throttle lock holding 1,200 rpm or so but will NOT idle normally when warm.  Bogs and dies within a second or two if throttle grip returned to idle.

Swapped back to original plugs in case I got a bad one.  Wiggled plug wires and any electrical connector I could find and nothing made a difference.

Checked down pipes from the engine and all approximately the same temperature (IR thermometer).  No major failure of fuel injector or ignition.

Checked MAP sensor connection and lines for "goop".  Also checked for obvious air leaks but I suppose it is possible I missed something.  (no reason anything should have been disturbed anyway)

Have not attempted a TBS yet.  Would have to hold throttle open so it would stay running.  Note: one of the rubber caps for the #4 sync port was torn but I replaced it.  Pretty sure it didn't happen while I was doing this work.

No obvious electrical anomalies (i.e. grounding problem).  Indicator lights, headlights, windshield etc. all work normally.

Two questions...

Is there any chance that the throttle body sync could be off enough (by changing the valve clearances) to cause the bike to not be able to idle?  I KNOW that the sync cap was not torn when I did the last TBS so I don't expect this is the issue.  I have never found the TBS made THAT much difference.

The more I think about it, the more I wonder if the cam timing is off.  I secured the chain to the sprockets with zip-ties before slackening the CCT.  Did the valve work with the cam lifted out of the way.  I did not do anything at the crank end but didn't do anything that should rotate the motor unless it happened when I was moving the cam back into position.  I have done it this way a number of times and never had an issue.

Edit:  I tried it with idle adjustment all the way in and air screws all open 3/4 turns.  No dice.  Tried with them all open 1 1/4 turns and still no good.  Shouldn't need to be further than that.

 

[RossKean]

Tore into it again.  Drained the coolant, pulled the timing cover and removed the valve cover.  Looks like the cams are OK with respect to each other (will have to check again in full daylight) but they are off one (maybe two?) teeth from the sprocket.  The engine ran so I assume it wasn't enough to do any damage.

I have done a fair number of valve checks and this is the third or fourth adjustment.  Never had an issue before...

Question on throttle cable routing.  Over or under the coolant pipe?  The original owner had it going under but I am thinking it should be over.  Less likelihood of causing binding.  Could someone confirm for Gen II?

 

[1911]

Mine go under.

 

[RossKean]

Mine go under.

Thanks.  After I posted, I found the routing diagram in the FSM which shows it although it is a bit difficult to follow. 

I am getting a bit of stiffness in the throttle return. I will check that there is sufficient free play and maybe a shot of lube is in order.

 

[Viper Pilot]

I think you found your problem with incorrect valve timing.  Most likely not FUBAR but enuf to affect how it runs.  

 

[RossKean]

I think you found your problem with incorrect valve timing.  Most likely not FUBAR but enuf to affect how it runs.  

I hope that is the case.  Will see if I have any difficulty getting it back into correct timing.  I have never done this before.

I think the intake and exhaust cams are OK with respect to each other but they are off at the crank.  Not 100% sure the best way to fix it but if I could manage without removing the cam caps that would be a bonus.  I guess I'll figure it out.

 

[Fred W]

The crank sprocket is the one that generally pops over a tooth when you slacken the chain.  I’ve found that the easiest way to get the timing right is with the CCT retracted turn the crank backwards (CCW) a few degrees, fit the chain on the sprocket then release the CCT and check the timing.  The reason to do this is it is hard to get the chain on the sprocket with everything at TDC due to the chain being tight between the exhaust cam and crank sprocket.

 

[Auburn]

The crank sprocket is the one that generally pops over a tooth when you slacken the chain.  I’ve found that the easiest way to get the timing right is with the CCT retracted turn the crank backwards (CCW) a few degrees, fit the chain on the sprocket then release the CCT and check the timing.  The reason to do this is it is hard to get the chain on the sprocket with everything at TDC due to the chain being tight between the exhaust cam and crank sprocket.

After you do that, make sure to check the cam sprocket marks line up with the head.  I had to paint the marks silver so I could see them clearly.  You will need plenty of light and patients.  Because you have to make sure there is no slack between the crank sprocket and exhaust cam.  took me three tries to get it right and get the marks lined up.  I ended up using a zip tie to keep the exhaust and intake cams from skipping teeth.  Then I got the slack out of the exhaust to the crank.  It's a PIA in the bike.  I'm sure it is a lot easier with the engine out, but you don't want to go there.

 

[Fred W]

I should mention that conventional advice is to never turn the crankshaft backwards, but nobody ever tells you why.  The reason not to is because the chain tensioner is on the chain between the crank sprocket and intake cam, if you turn it backwards at the crank you are pulling the chain tight against the CCT, which it is not designed for.  It can compress which would create slack and allow the chain to skip teeth on the sprocket. 
 

However, when the CCT is already compressed and the chain is already intentional loose it is OK to turn the crank backwards or forwards a little to move the chain links on the sprocket to establish correct timing.  Once you think you have the timing right, tension the chain and only turn forwards (CW).