Are we sure my timing is out????? Help please

[VTRDark]

For the timing to be 180 out would require removal of cams so the likelihood is that either valve clearances have been done and new shims put in or there has been a previous CCT failure and the head removed/replaced which also requires the removal of cams. Timing at the crank has either not been set beforehand or has been moved while the cams are not in place. Simples

nope because i replaced the ccts with manuals and done it without even touching the timing

You where taking a risk there as the camchain may have not been at it's slackest point so while under tension and removal of CCT you risk the chain jumping teeth.

plus its done this since i bought the bike.

Possibly previous CCT failure then as mentioned above.

(:-})

[agentpineapple]

nope because i replaced the ccts with manuals and done it without even touching the timing plus its done this since i bought the bike.

I take it you didn't buy the bike from new, so are you sure the cct's hadn't been replaced before you owned the bike? (some owners replace oem cct's with another pair of oem cct's) so when you replaced them it was already 180 out, so the problem still remains....

[Bleh]

Ok, so I've been reading this thread and the only thing my little mind can't work its way around is the 180* out business.
Yes, I can see how it could be out if someone has miffed the cams about but I can't see for the life of me how it would still be ride-able at 180* out... That to me would imply you're getting ignition at (around) BDC (don't actually know ignition timing on the VTR ) and therefore only firing on one!

To be able to ride at 180* out, for me, goes against all logic of a four stroke cycle.

Please, someone explain to me how this can be 'masked over' with fueling etc, I'm genuinely struggling. I mean, I've had mine only firing on one (dead plug) and the thing didn't sound right (one of them 'there's some crap in the carbs which I'll blow out' sounds) and barely moved (lumpy not the word) - I couldn't make it out of my (small) street without having to turn around and get the car instead.

I'm not trying to challenge anyone's voice of experience but instead learn from it and better my own understanding. But to me, it just does not sound logical. Even theoretically it shouldn't work as at 180* out, there's minimal compression within the chamber and if there is ignition at or near BDC, the piston will have hell of a lot more work to do to get to TDC which it HAS to do... Or are we saying that the bike is basically a 500 single whilst these problems are arising? But even then, it would only tick over at half RPM (or at least, less than what it should be).

Personally, if the problem is only between 6,500 and 7,500 revs and clears after that, I'd start with the simple things, i.e. Air intake (no obstruction within the venturi for example) and fueling. Assuming the exhausts are standard, ensure there's no obstructions but if not standard, consider the difference in lengths as that can play a part etc etc, blah blah blah.

But again, please would someone explain the 180* out and still running and ride-able scenario?

[AMCQ46]

Cams are 180 out, the crank is 360 out, so still at TDC for the firing as it has a wasted spark ( fires at every tdc)

[8541Hawk]

Ok, so I've been reading this thread and the only thing my little mind can't work its way around is the 180* out business.

To be able to ride at 180* out, for me, goes against all logic of a four stroke cycle.

Actually the issue you are having understanding this is that you are slipping into 2 stroke logic.

On a 2 stoke, if you are 180 out you are at BDC.
On a 4 stroke, 180 out is TDC just on what would have been a different cycle and it will fire just fine as this system uses a "wasted spark"

So what happens when you are 180 out on this bike is instead of having a 270-450 firing order you end up with a 270-270 firing order which gives the crank a real long time to coast before you get to fire the pistons again.

[darkember]

In essence the cylinders will fire in quick succession one after the other giving the effect of faster lowdown torque and acceleration. Only as the speeds increase does the issue start to present itself.

[VTRDark]

Please, someone explain to me how this can be 'masked over' with fueling etc, I'm genuinely struggling.

TBH I struggle to get my head how but in the case of AP's bike it had smaller mains IIRC 150s. This does not totally fix the symptoms of 180 out but seems to allow one to get past 7000 and ride the bike, even for two years in AP's case whereas others become unridable and behave more like a limiter. I put his carbs back to standard and things where worse and then we realised there was another issue going on, so after going through the standard things like plugs, coils, swapping out ecu's, changing the pulse generator etc, we eventually came to the conclusion that his bike was 180 out, which it was.

Or are we saying that the bike is basically a 500 single whilst these problems are arising?

Pretty much. It's juts the one airbox that stops it. Mr Mon is thinking of experimenting and splitting the airbox into two. As being 180 out with the one airbox one cylinder only gets half a breath.

(:-})

[fordstorm]

ok im pretty much starting to understand but is there an actual way to check that it is out 180
is it by looking at were the cams are? or is there no way of telling and you just hope for the best and turn the crank 360

[VTRDark]

This is why there is an issue and lots of people get the timing mixed up if not done in a systematic order. As far as I'm aware there is no easy way of telling from appearance as all the timing marks line up the same and look correct. So I would suggest removing cams, rotate crank and replace cams and road test.

Set rear cylinder to TDC on the compression stroke (crank at RT and cam lobes pointing up and in), remove cams and it's best to have a helping hand to hold the chain and feed it around as you turn the crank 1 turn anticlockwise until the RT comes back around. Then put the cams back in place with the lobes as before pointing up and in.

If one wanted to do it the hard way you could change the front cylinder to achieve the same end result. The only difference being the timing marks (crank at FT and cam lobes pointing up and out).

(:-})

[AMCQ46]

Ford....there is a fairly easy way to tell if it is out, and that is to :

A) remove both cam covers
B) set the engine on the rear tdc with the cam lobes in the correct and symmetrical position (can't rememberif it is towards each other or away, but it is detailed in Sirch' CCT instructions the workshop knowledge base)
C) then rotate the engine 1 and 1/4 revs counter clock wise
D) look at the front cam position.... It should now be at the firing tdc, with the cams symmetrical and in the opposite direction to the rear position ( and neither cam should be pushing onto the valve). And the marks onthe cam sprockets should be parallel with the cam cover sealing face

If you are 180 out, the cams will be opening the valves.

If you are 180 out,then come back for the rest of the instructions

[8541Hawk]

Ford....there is a fairly easy way to tell if it is out, and that is to :

A) remove both cam covers
B) set the engine on the rear tdc with the cam lobes in the correct and symmetrical position (can't rememberif it is towards each other or away, but it is detailed in Sirch' CCT instructions the workshop knowledge base)
C) then rotate the engine 1 and 1/4 revs counter clock wise
D) look at the front cam position.... It should now be at the firing tdc, with the cams symmetrical and in the opposite direction to the rear position ( and neither cam should be pushing onto the valve). And the marks onthe cam sprockets should be parallel with the cam cover sealing face

If you are 180 out, the cams will be opening the valves.

If you are 180 out,then come back for the rest of the instructions

You beat me to it..... but +1

[agentpineapple]

Ford....there is a fairly easy way to tell if it is out, and that is to :

A) remove both cam covers
B) set the engine on the rear tdc with the cam lobes in the correct and symmetrical position (can't rememberif it is towards each other or away, but it is detailed in Sirch' CCT instructions the workshop knowledge base)
C) then rotate the engine 1 and 1/4 revs counter clock wise
D) look at the front cam position.... It should now be at the firing tdc, with the cams symmetrical and in the opposite direction to the rear position ( and neither cam should be pushing onto the valve). And the marks onthe cam sprockets should be parallel with the cam cover sealing face

If you are 180 out, the cams will be opening the valves.

If you are 180 out,then come back for the rest of the instructions

I hope he doesn't lose internet connection when he comes back for further instructions.....

[Bleh]

Thanks all, is making a bit more sense now. But aren't we starving the engine of fuel mix if the cams are 180* out? We're essentially swapping the valves around??!!

So, thinking about this ugly scenario and the fact it will still fire at 180* out through the 'wasted spark' (coutesy of hawk ), there should be a concern of detonation (different to combustion but I'm not the best at explaining this aspect), the unwanted by-product(ish) of combustion. This could explain the feeling of extra torque at low end but it's not good for the piston or valves et al. and they can easily caulk up or worse.

Hope you get it sorted soon. It really winds me up when mechanical ignorance is passed onto some other individual who then has to rectify it. My bikes may not look pretty but they have the right stuff to make them mechanically tip top - it's the safest way to be.

Good luck

[fordstorm]

I will be doing the work on my bike today so will let you all know the outcome.

Never to run again i expect

[fordstorm]

oh wombles the worst that could of happened has happened I sorted the timing issue out went to put it back together and dropped the bolt out of the cam chain cover down the engine wombles great I now will be taking the engine out tomorrow after spending the whole day trying to find the bolt with no success I could cry