Started hearing alot of top end noise, Valves are in spec ok, But did notice some metel dust on the outside end of the intake cam lobe. Can anyone tell me what i am looking at. I have a 2007 RMZ 250 with maybe 30 hours on it. Oil is changed every after every 3 or 4 rides.

90 Storm, must be in Canada, 1,6 (the comma tells me this)
the storm is a:
The car is really an Isuzu Impulse minus some of that car's more expensive features.
my guess is you drove the this 4EX1 engine until the cam belt slipped. yes> if yes you bent valves.????????????
so does compression exceed 150psi on all 4 cylinders now?
we use the cylinder leak down test in all DOHC .
if not , back to the drawing board.
if yes, the we check spark next, then try test fuel.
when did the engine last run , last week,month , year,?
who did your valves, a real machine shop or kid down the street.
a read shop pressure tests the head ,and warp checks it and
then makes sure the valves are ready for long service.
are the head bolts at 58 ft/lbs
did you use sealant on the 3 cap caps, per the FSM book.
if not , top end oiling will fail. and cams wrecked.

the 1.6l DOHC has no HLA's
the lash on valves must be checked, and this is corrected with SHIMS.

a pro machine shop does the for you,did they:?
when rebuilding engines, its best to read the factory service manual first. FSM so you know the special steps just for this engine.
ISUZU engine it is.



quote.
1.6L Twin Camshaft Engine

1. Disconnect the negative battery cable.
2. Remove the cylinder head or valve cover.
3. Position the No. 1 cylinder at TDC on its compression stroke.

The notch on the crankshaft pulley should align with the 0 degrees mark on the timing gear case. Make sure the rocker arms on the No. 1 cylinder are loose and the rockers on the No. 4 cylinder are tight. If not, turn the crankshaft one complete revolution and align the marks again.

1. Using a feeler gauge, measure the clearance between the cam lobe and the selective shim on the intake and exhaust valves on the No. 1 cylinder, then the intake valves on the No. 2 cylinder and the exhaust valves on the No. 3 cylinder. Note readings.
2. Rotate the crankshaft 360 degrees. Using a feeler gauge, measure the clearance between the cam lobe and the selective shim on the intake and exhaust valves on the No. 4 cylinder, then the intake valves on the No. 3 cylinder and the exhaust valves on the No. 2 cylinder. Note readings.
3. The valve clearance obtained on the exhaust valves should be between 0.008-0.012 in. (0.20-0.30mm). If not, replace the selective shim by turning the camshaft lobe downward and installing tool J-38413-2 or J-38413-3 (valve lash spring spacer) between the camshaft journal and the cam lobe next to the selective shim. Turn cam lobe upward and remove the selective shim. Install new shim using the selective shim chart.

The rear camshaft bearing caps must be removed to remove the selective shim.

1. The valve clearance obtained on the intake valves should be between 0.004-0.008 in. (0.10-0.20mm). If not, replace the selective shim by turning the camshaft lobe downward and installing tool J-38413-2 or J-38413-3 between the camshaft journal and the cam lobe next to the selective shim. Turn cam lobe upward and remove the selective shim. Install new shim using the selective shim chart.
2. When the adjustment is completed, install the cylinder head covers and connect the battery negative cable. Start the engine and check for leaks.

end fsm quote.

see those 2 marks, and crank must be at TDC. mark first.

There are two TDC's, TDC of the compression stroke, both cam lobes will be up, away from the valves. On TDC of the exhaust stroke, the exhaust lobe will be just past the exhaust valve, and the intake lobe will just be ready to open the intake valve. See, as the piston rises on the exhaust stroke, the exhaust valve is open. When piston reaches TDC, the exhaust will close, and the intake will be opening as the piston begins downward again. Coming up on the compression stroke, and on up to TDC, both valves remain closed-lobes are away from valves.

these are known for carbon build up on the valves that cause several problems.this could be the problem as the carbon can cause the valves to stick a bit in the valve guides while its running and show up as a ticking noise with the gas applied.have the top end service done which cleans the fuel system injectors and any carbon build up on the back of the valves.if this gets bad enough it can cause the cam holders to break locking up the motor if the piston hits the valve.another thing to check is oil pressure and the lifters may be worn to the point that they need replacing.check the cam lobes as well if worn these can cause a ticking noise on acceleration.

Set the piston to TDC (top dead center) this is the higest point the piston will rise before moving on to the down stroke, either by lining up the marks on the crank rotor or a long screw driver (large handle so it wont fall in) down the plug hole and watch for the highest point lock or hold at this point. The cams should be fitted next on the 'compression' stroke meaing the all valves should be closed when the cams are seated (no valves being pressed by cams) generally at this point the cam lobs face away from the valves, next stroke down (ignition of fuel) valves should be closed with the exhaust cam moving round ready to rock on to the exhaust valve as the piston rises to the top again (4th stroke exhaust) as the exhaust valve lobe rocks off the intake cam lobe should be starting to rock on opening the intake valve on the down stroke of the pistion.
Trun the engine over by hand to make sure no valves are knocking the piston.
Should be as follows
1. all valve clearance free/rocking at ' TDC 1st 'down' stroke (ignition of fuel) valves closed exhaust moving round but not pressing valve ,
2. 2nd stroke 'up' exhaust valve rocking open and closing as piston tops with the intake ready to rock on as the exhaust closes and piston tops (exhaust),
3.3rd stroke 'down' (intake of fuel) as the piston moves down the intake valve should be opening.
4. 4th stroke 'up' compression of fuel all valves rocking closed as the piston rises for the compression stroke back to TDC all valves closed/rocking free.

Intake, compression , ignition and exhaust. (**** squeeze bang blow)

Set the piston to TDC (top dead center) this is the higest point the piston will rise before moving on to the down stroke, either by lining up the marks on the crank rotor or a long screw driver (large handle so it wont fall in) down the plug hole and watch for the highest point lock or hold at this point. If cam sprocket has marks line them with the cylinder head surface (sometimes the sprocket bolts) parallel.
The cams should be fitted next on the 'compression' stroke meaing the all valves should be closed when the cams are seated (no valves being pressed by cams) generally at this point the cam lobs face away from the valves , next stroke down (ignition of fuel) valves should be closed with the exhaust cam moving round ready to rock on to the exhaust valve as the piston rises to the top again (4th stroke exhaust) as the exhaust valve lobe rocks off the intake cam lobe should be starting to rock on opening the intake valve on the down stroke of the pistion.
Trun the engine over by hand to make sure no valves are knocking the piston.
Should be as follows
1. all valve clearance free/rocking at ' TDC 1st 'down' stroke (ignition of fuel) valves closed exhaust moving round but not pressing valve ,
2. 2nd stroke 'up' exhaust valve rocking open and closing as piston tops with the intake ready to rock on as the exhaust closes and piston tops (exhaust),
3.3rd stroke 'down' (intake of fuel) as the piston moves down the intake valve should be opening.
4. 4th stroke 'up' compression of fuel all valves rocking closed as the piston rises for the compression stroke back to TDC all valves closed/rocking free.

Intake, compression , ignition and exhaust. (**** squeeze bang blow)

Heres a few solutions. There could be several reasons for that noise.
1.
Check your valve clearance at TDC. Adjust if needed.
Intake should be .03mm
Exhaust should be .05mm
2.
Check your oil level, if your low, then you'll start to hear the rockers, because they are not getting the oil needed.
3.
Change your oil filter, a dirty oil filter will cause a drop in oil pressure, depriving the top end of sufficient oil and you'll here the rockers.
4.
If your still hearing noises after the above solutions are checked, you'll have to pull the rockers off, and inspect the cam,and valves, check for cam bearing wear, cam wear, bent valves, valve to valve guide clearance. You'll find it. Replace the parts worn or bent.

DOHC cam lobes are mechanically on top of valve stems, no rockers to adjust.

hi, on your vehicle the valves are not adjustable after about 1990 they started using hydraulic lifters, so if you have top end engine rattle then the chances are these lifters will need replacing or worse case the cam lobes could be worn if this is the case then your going to need to do a top end rebuild.

to replace the hydraulic lifters your going to need to remove the cams so as you can get to the lifters under neath the cup they sit under so its quite a big job.

the older type valves were a lot easier as you could adjust them with screwdriver and measuring guages but they started using the new ones as they made less noise and lasted longer, but the downside to this was that you need to do more work to replace the lifters.

let me know how you get on or if you need further assistance ok

The ticking sound is most likely caused by uneven wear on the cam lobes. The next time you've got the valve covers off, take a look at the cams and you will likely see scuff marks on one or more of the high-points of the camshaft lobes. This can cause a ticking sound each time that part of the lobe comes in contact with the rocker arm. The only cure for this would be to replace the cam and rocker arms - which is not worth the many $$ it will cost. The noise may be annoying, but isn't anything to worry about. My Goldwing started making a ticking sound at about 90,000 miles - and continues to this day, now with more than 169,000 miles on the engine.
Uneven cam lobe wear can also cause lateral movement of the rocker arms - and a ticking sound as the rockers move slightly sideways on their shafts (note the springs on the shafts that hold the rockers lightly to one side).
I should also mention that pitted valve stem tips can also cause a ticking noise. In any event, do not run the engine with less than the specified .004" valve tappet clearance as this can cause valve damage and compression loss.

Hello redevil67...This is normal for the HD engine, it going to have valve train, top end noise at some point, some as early as 2000 miles. If you take it to the dealer they will try to sell you on worn tappets...key word here SELL..I've seen this many times, dealer replaces componets, 2000 miles later the noise returns.
These are hydraulic valves and as you probably know they operate at zero lash. Personaly, i feel that the problem is that the cams are not hardened properly or machined incorrectly.. When the leading edge of the cam lobes wear to a strange profile it tends to snap the lifter up in the lifter bore. This causes the rest of the valve train to rattle. You hear the noise on top but the culprit makin it, is the cams..Many chose to go with an aftermarket cam, such as an andrews...Another suggestion, is to switch oils. Don't know what you are useing now, but i'm not a fan of dino oil. As the temperature builds the more an oil is stressed. Lucas full synthetic 20w-50 or Mobil1 15w-50 are both excellent for anti-wear and long term protection.
I hope this helps, please rate me a fixya and good luck with your bike.