Cams done at 40,000 km?

[skipperT]

@partypat , can you elaborate/define "wrong" oil? I assume you're referring to sheer/viscosity/additive characteristics and not mineral vs synth.

I am just referring to using Motorcycle specific 4 stroke oil.   Commonly shown with the 4T on the label.  These oils contain zinc which is required to protect the valve train from wear.    
The damage we've seen is normally when automotive oils are used.  They don't have the correct additives.
 
Pat

 
Yep. I’m not trying to start an oil thread, but the other thing that’s important is oil suited for a wet-clutch system, which most auto engine oils are not.
 
Read the bottle before using, YMMV.
 
-Skip

[skipperT]

I could be wrong, but I think the lobe height min/max are for new cams. The limit is the wear limit, since they will only ever get smaller with wear, not larger.

 
Yes, I’d agree.
 
If you had access to 10 brand new camshafts to measure, they would all have to be in that acceptable range. When we’re taking about several 10 thousandths of an inch, some manufacturing tolerances are acceptable. Same with the journals of the cyl head, which (I think) are line bored by a marine during manufacturing. These measurements dictate oil running clearance.
 
Which is why tightening those cam carrier caps evenly is SO IMPORTANT. A small scale, 1/4 inch drive torque wrench that starts around 30-40 inch lbs and maxes out at over 12ft lbs is the best tool for that job. Not your 3/8 inch drive wrench that starts around 5 ft lbs. Unacceptable in my opinion.
 
You break a cam carrier, you replace the cyl head because they are machined together and aren’t sold separately.
 
Honda cyl heads with actual cam bearings on each end of the unicam might be the exception (crf 250/450 maybe?) Don’t remember off the top of my head (lol)
 
-Skip

[skipperT]

Upshift - based on your posts, I’d say the valves definitely need adjustment. Personally, I’d run the cams as is for now and see if the bike runs better with proper valve lash and a TB sync. (Remember valves have to be in spec BEFORE an accurate sync can be performed. )
 
If it runs better initially when you get it back, and quickly gets worse again, and the clearances have moved again within a short number of miles, then I’d consider cam replacement and pulling the valves from the cyl head for inspection and lapping the seats as necessary.
 
Was a leak-down test performed? How are the rings sealing? Spark plug condition? Intake tract clean or is there a lot of carbon buildup? Any trouble codes stored/current? Fuel type/quality/octane/age? Fuel pressure test performed?
 
Other diagnostics to consider.
 
Good luck, YMMV. Let us know if you need more help- but sounds as if you have a guy with some skill working on your bike, so that’s good. You might want to consider NOT telling him you posted all this info on a forum, depending on how his ego is....
 
-Skip
 

[captainscarlet]

I'd like to weigh in with a slightly different view here.
 
Firstly it seems somewhat strange that your mechanic would go directly for the camshafts.  The valve check does not call for measuring the camshafts.  Indeed checking the camshafts is not a part of the maintenance schedule at all.  I assume that as you haven't brought it up that your valves were in spec?  Having checked the camshafts it's clear from the service manual that they are within wear tolerances so no problem there.  Put the camshafts back in the bike and be happy.  Obviously you know your mechanic but I'd be a little concerned that he doesn't have the relevant numbers/experience for your bike and is providing feedback that could lead you to replace expensive parts completely unnecessarily. 
 
You described that your bike was running a little rough and you noticed some surging.  Firstly our beloved CP3 engines are not exactly known for being super smooth on a constant throttle at lower speed, particularly on North America spec bikes.  The list of things that could be causing your issue is very long, before we get anywhere near major mechanical ailments in the guts of the engine.
 
Surging is much more likely to be caused by something in the fueling system.  Is the bike running lean?  Has the mixture been checked?  I would be looking at a throttle body sync to start with, checking fuel lines, plugs, maybe the O2 sensor is going haywire or something else in the fuel control system.  Have you ended up with some dodgy fuel on your trip perhaps?  A blocked fuel injector?
 
Those are the things I'd be looking at first, not cams or valves.  Frankly I'm surprised your mechanic isn't looking at those things too.
 
Hope you get it sorted.
 
CS

[upshift]

Thanks much to @skipperT, @captainscarlet, and others for ringing in on this. Much appreciated!
 
Again, to answer some questions:
 
1. I'm not sure what a "leak down" test is but compression was checked and determined to be fine. I replaced the spark plugs and cleaned the K&N air filter mid-trip in an attempt to sort out the roughness. Also thought about bad gas and siphoned the tank and replaced with fresh stuff (I always use 91+ octane). None of that seemed to make a difference. Bike hasn't thrown any codes so I don't think it's anything major. Haven't performed a fuel pressure test at this point.
 
2. I trust my mechanic - he's a good dude who's super conscientious and does lots of little things that I wouldn't think to do (like check cam lobe specs, just to see how they're faring). He's forgotten more about engines than I'll ever know and I don't believe he's trying to squeeze me for unnecessary work, just trying to be thorough. We talked yesterday and he's putting the OEM cams back in the bike, as they're within limit specs (albeit barely). He's ordered some shims for the valves and then will do a throttle body synch and we'll see where we are.
 
3. Agreed, @captainscarlet, about the CP3 having a few rough edges, including the fuelling loops sometimes being the culprit. I had disconnected my O2 sensor (on the advice for Nels at 2wheeldynoworks) a while back but tried reconnecting it on the trip, in case that helped somehow. Didn't help so will be disconnecting again.
 
4. I probably should have mentioned that I had to get a new chain mid-trip, as the one I had had developed a tight spot that was contributing to the surging feel. That helped a lot. The shop I took it to didn't have sprockets to install at that time so my mechanic is doing that now. Thinking about dropping a tooth or two on the rear for better highway cruising - anyone done this and want to ring in with suggestions?
 
Again, thanks to all for ringing in on this - great to have such a generous community to lean on!

[betoney]

Thinking about dropping a tooth or two on the rear for better highway cruising - anyone done this and want to ring in with suggestions?

 
From what I have been able to find, front sprocket options are 15/16/17 and rear is 43/45/47.  Your cheapest bet would be to buy a 17T front (about $25-30) to see if you like it.
 
 
 
Gearing is completely dependent on the type of rider you are.  To me, the motor seems happiest when I keep it over 4,500rpm, though I am more of a sport-minded rider and dont like to lug the engine.  When I had stock gearing I rarely used 6th gear even on the interstate unless it was extended riding at 75+mph.  The gearing seemed way too tall for my riding style.
 
 
I swapped to a 15T front and loved it, that stayed on through the life of the first chain.  When I bought a new chain and sprockets I chose instead to change the rear to 47(+2) as its very close to 15/45 and love the way the motor responds with lower gearing. 
 
 
 
 
 
 
 

[skipperT]

Thanks much to @skipperT, @captainscarlet, and others for ringing in on this. Much appreciated! 
Again, to answer some questions:
 
1. I'm not sure what a "leak down" test is but compression was checked and determined to be fine. I replaced the spark plugs and cleaned the K&N air filter mid-trip in an attempt to sort out the roughness. Also thought about bad gas and siphoned the tank and replaced with fresh stuff (I always use 91+ octane). None of that seemed to make a difference. Bike hasn't thrown any codes so I don't think it's anything major. Haven't performed a fuel pressure test at this point.
 
2. I trust my mechanic - he's a good dude who's super conscientious and does lots of little things that I wouldn't think to do (like check cam lobe specs, just to see how they're faring). He's forgotten more about engines than I'll ever know and I don't believe he's trying to squeeze me for unnecessary work, just trying to be thorough. We talked yesterday and he's putting the OEM cams back in the bike, as they're within limit specs (albeit barely). He's ordered some shims for the valves and then will do a throttle body synch and we'll see where we are.
 
3. Agreed, @captainscarlet, about the CP3 having a few rough edges, including the fuelling ...
 
4. I probably should have mentioned that I had to get a new chain mid-trip, as the one I had had developed a tight spot that was contributing....
 
Snip
 
Again, thanks to all for ringing in on this - great to have such a generous community to lean on!

 
1- Compression tests are fine but somewhat worthless from a diagnostic standpoint.
A leak down test puts a measured and regulated amount of air (usually from shop air line) in the combustion chamber via the spark plug hole when the engine is set to TDC or BDC on each cylinder. Gauges monitor how much air is going IN vs how much air is coming back OUT on a second gauge. This is how the leak down percentage is calculated. It is infinitely more valuable because it allows you to see if air is escaping past the piston/rings/cylinder areas, intake valves, or exhaust valves, as well as if the head and base gaskets are working.
 
Compression tests are a good fast check of engine health because they are performed at cranking speed (dynamic test), but leak down can pin point more accurately WHERE something might be amiss.
 
Out of adjust valves can be turned up on a leak down as well, if they are stuck partly open. A compression test also might turn it up with a lower than usual value, however many of today’s single cyl engines use auto decompression systems that render a compression test useless because the measured comp number is lower than operating comp. You can’t physically spin the engine fast enough with a kick start or starter motor to get an accurate number.
 
2- the fact that he took the time to measure the cam shows how meticulous he is. Solid stuff. That was above and beyond for sure, but an important step to KNOW that the cam is in good shape.
 
4- as I mentioned in another thread, you can definitely “feel” a worn out chain/sprockets. Glad to hear one component was renewed, but you just may have had multiple things causing your running complaint.
 
Your plan sounds good to me. Reassemble with the new shims and (hopefully) clearances in spec. Adjust TB sync and get the drive train sorted, and you may find yourself all dialed in.
 
-Skip