Valve Timing Dots

Hi All , went for my first ride after a refurb ,sprang a couple of oil leaks from cam cover so pulled the cover only to find the valve timing was out by quite a bit so fiddled around adjusting it and the best result thus far is what you see in the pics. Is this alright ? I am sure its at true TDC, it appears the exhaust cam sprocket has been replaced and I am assuming its aftermarket, maybe this is why the exhaust mark is out a tad. Will I get away with how it is now ? Prompt reply appreciated as I wanna go for a ride.

 

If your crank is at TDC, then your exhaust cam is one tooth off. You have the manual for the reset process?

 

It's not a full tooth off.

 

You don't think so? I'm looking at the intake cam, it could probably be rotated a degree or three more forward to line up perfectly. That would move it forward a little more. What else would contribute? A stretched chain? (No sarcasm intended, actually wondering what else would cause it to be off)

Here's a shot of mine when I was off one tooth, pull the tensioner and cam gear off, moved the cam back to the dot and bolted the cam gear back on. After putting the tensioner back in and rotating once around, it was lined up.

 

His isn't as far off as yours was (to my eye).
An aftermarket cam sprocket could explain it (though his looks to be stock). That was a fairly common method for altering valve timing just a little, but I don't recall them being used on the XJ series. Chain stretch (really roller wear) could also explain it (and be the more likely cause).

I'm looking at the exhaust.
The intake dot is spot on at TDC. If you rotate the intake cam by one tooth, then both cams will be out of time.

 

It was miles off before I adjusted it, the intake was retarded 1 tooth and the exhaust advanced one tooth, I only used a marked dowel to find TDC and adjusted the pointer accordingly, No I don't have a manual but have read a lot of threads on here. first I set the exhaust, was lined up, then set the intake was lined up turned the engine anticlockwise 2 turns to get back onto compression no 1 TDC and the intake was lined up but the exhaust was retarded so took the sprocket off and moved it a tooth and it ended up where you see it now, I am inclined to blame chain stretch or roller wear.Do I risk putting it together as is or try and get it closer if I can. Thanks for the input.

 

Okay I did another check of TDC and marked when the Exhaust was on the dot then when the Intake was on the dot.It looks like the Exhaust is on the money,the question is, will I get the Intake any better ? Do you think it is one tooth out ? or maybe just chain wear ? See pics

 

Now that I look at all the pics on a computer, K-Moe is right. Mine looks like it was off more than yours.

Not sure what to tell you next. If the chain is tight across the top of the sprockets and that is the closest you can get it, then I'd suspect the chain is worn. I think there was another thread on here where the guy had the same issue and ended up replacing the chain to fix it.

Would I run it? I dunno. I'm OCD about these things so I wouldn't. With each tooth on the cam being about 11 degrees, a half a tooth would be about 5.5 degrees. I don't know eough about engine performance/building to know how that would effect it.

Two things to note;

That's not the complete/proper process. There are links to get free manuals. If you have the 650 PM and I can get you one.

You shouldn't move the pointer. It is factory set/sealed and you will never be able to get as close with the dowel method. The dowel method is good to verify if the pinter has been bent etc. but from the factory it will be accurate.

 

Thanks Jayrodoh,
I appreciate the input, I checked it again and had both dots lined up perfect, turned the engine two turns and back with the same result, so yup I am putting it down to chain wear, it is right at the end of its adjustment.The pointer had to come off when I split the cases to replace the starter clutch and man it has one big slotted hole so I have set it with the exhaust on the dot, yeah I know I should have replaced the camchain when I had the engine out but you have no idea how hard it is to get parts here in Thailand for big bikes and I am fed up paying lots of bucks for postage from the States, so for the time being I am going to run it, it is a lot better than how it was set up before and I have already done 120 klms with the previous settings so can only be better. Carbies back on tomorrow and take it for a spin, will keep ya posted...... Cheers Dino....... PS I downloaded the manual today.

 

Ah, didn't realize you had split the cases. Makes sense then. Good to hear it's better than before thought!

I hear that international shipping can be a deal breaker.

Good luck!

 

The timing pointers are not always as they were when set at the factory. Even the service manual reccomends finding TDC (with a dial indicator) and double-checking when setting cam timing.


Personally I'd have no issue with running it until I had a new chain and master link in-hand. You can break the old chain and use it to thread the new one on without needing to remove anything but the chain tensioner and the valve cover.

 

I didn't think you needed to remove the pointer when splitting the cases, not that it matters now. I still have mine on with the cases split.

 

You don't have to, but they are pretty easy to bump out of place.

 

OK, I read that in the manual so I have been trying to be careful not to knock it. I'll be going through all this fun soon enough, I guess, since I'll need to remove the chain.

 

...eventually. Replacing the cam chain is a cakewalk in comparison to the work you did when you split the cases (and you don't have to do that again).

 

It was a flogged out chain, put it together with the correct valve timing, compared to what it was its a hell of a lot better, car has just blown a rear calliper so need the bike while I sort that out, will get around to replacing the chain when I got wheels again..... thanks again for all the input guys