intermittant misfire

[wildchild74]

Highly unlikely the tensioner is a problem, mostly like a wearing chain or valve clearance to big.

Cam Chains like drive chains do not wear uniformly they have loose and tight spots. This causes a light rattle especially on startup and the only know cure is to replace the chain.

What mileage is on the engine?

The tensioner is easy enough to remove if you still want to.

Remove the alternator/Generator cover.
Rotate the the crank anticlockwise until the T mark lines up with where the top and bottom crankcases meet.
Some will say you do not need to do this, but it is the best position to have the chain in when removing the tensioner.

Do not rotate the crank when the tensioner has been removed

Remove the 10mm bolt at the end of the tensioner. There is a ball bearing within the bolt, don't lose it.
Don't lose the copper washer on the bolt
Remove the springs (one is inside the other)
Loosen the two allen bolts and carfully remove the tensioner.  There is another ball bearing inside in the tensioner don't lose that either.
If your lucky the gasket will remain intact, if not replace it. It is probably best to replace it anyway.
Lift the ratchet and push back the tensioner.
Oil it up and with the ratchet held off the tensioner push the tensioner in and out of the housing a few times.

Replacment is more or less the reverse order of the removal.
Tensioner pushed back into the housing
Gasket
Tensioner body
Tighten the Allen bolts to 10Nm
Ball bearing
Springs
Push them in to the tensioner (You will hear the ratchet clicking over the ratchet teeth)
Put Ball Bearing into cap Bolt and copper washer on the bolt.
Put it on the tensioner and tighten it to 20Nm

Now rotate the engine slowly two full turns. You will probably here the ratchet taking up a little more slack.

You might as well check the valve clearances as you have the Alternator/Generator cover off if not

Put the Alternator/Generator cover back on and tighten the Allen bolts to 12Nm.

M8 your a life saver thanks for the info... why do i need generator cover off so i can turn engine over by hand?? And does the rocker cover need to be off to check clearances i presume yes the reason i ask this is because the mechanic said it could be down to the valve clearances the misfire but its not hard to start.... thanks again
Gaz

[unfazed]

Only way to turn the engine over easily and match the timing marks is with the cover off.

Taking out the plugs makes it easier too as there would be no compression to cope with.

with care the Cam cover can be removed with out resorting to removing all the bit the manual says to be removed

Seat off, Tank off, bolt in thermostat housing off.

Pull plugs off and back up to the level of the coils

4 End caps off

8 Cam cover bolts off

Tap the cam cover to unstick it

Take care of the rubber seal it can be reused if not damaged

This is the fiddly bit, trying to maneuver it out, using three hands move the thermostat housing and throttle cable as needed to give a little bit more clearance to take the cover out. It will only come out to one side, I will leave you to discover which 

Plugs out

Alternator Generator cover off

Set timing to T mark as explained in last post

Inlet and exhaust of one of the outer cylinders (1 or 4) can be checked and the inlet or exhaust of cylinder 2 or 3  and  exhaust of 2 or 3 can be checked.

Rotate the crank 360 degrees and check the remaining group.

Lightly Grease the rubber seal  and rubber seals on cam cover bolts before refitting

The same fiddly issue problem when trying to get the cam cover back in place.

Cap bolts are 9Nm
Cam Cover bolts are 10Nm

[wildchild74]

Aaarrrrr give me strength this fucking bike is frying my brain now n soz for swearing but so far ive changed plugs,leads,coils, now the carbs and still the problems still there no1 cylinder missing so what do you think folks and ive taken a 22 second video of it and it sounds like clattering at the top of cyl 1 can anyone tell me how upload the vid thanks
Gaz

[wildchild74]

Bump anyone
Gaz

[unfazed]

Go to additional options on the post window and click the + sign.

One cylinder ???? sounds like a valve problem maybe an exhaust valve burned or clearance to tight.

Take off the cam cover and first check the valve clearance.

Then again how do you know the replacement carbs are ok.

What way are you counting the cylinders when sitting on the bike. Is your 1 on the left or on the right????

[wildchild74]

Go to additional options on the post window and click the + sign.

One cylinder ???? sounds like a valve problem maybe an exhaust valve burned or clearance to tight.

Take off the cam cover and first check the valve clearance.

Then again how do you know the replacement carbs are ok.

What way are you counting the cylinders when sitting on the bike. Is your 1 on the left or on the right????

Hi m8 sitting on the bike its on the left...starts on the choke ok but off the choke it misses but when i turn it off then restart it starts perfect....ive only got rmt's word that they were ok and i specifically asked if there were any running issues and he said no so i put them straight on and its displaying exactly the same symptoms as b4 but the only difference is that if i put the choke on when its warm now it will run and not cut out where as b4 it would chugg and then cut out i dont know if that means anything...
cant upload vid as its too big
gaz

[greenman]

Have you checked plug caps, mine died at 40k miles, was a different bike when they were replaced.

[wildchild74]

Have you checked plug caps, mine died at 40k miles, was a different bike when they were replaced.

Hi m8 I have just got a new set this weekend. but while I've got the carbs off I'm going to strip out the jets n give em all a good blast thru with carb cleaner and give them a general clean as when I drained them the petrol was full of tiny black bits. I put the fazer on the bay last Sunday n was looking at ninjas but I gave the fazer a clean n started it n for that first minute or two running on the choke apart from the slight misfire it sounded lovely n then thought I can let it go for peanuts so took it off eBay n decided to keep it so I'll keep you all posted
Gaz