Mcct - fact or fiction???

[BrianC]

Been following a thread on Facebook where some character was saying you could fit mcct without removing carbs and cam covers.

Now ive done two of these and i cant for the life of me see how you can ?

How do you check cams are in right place?

How can you set chain tension?

Anyway, im helping a local newish member to fit his mcct s next week and will follow the guide from here

Discuss ?

[VTRDark]

Well I suppose you could find compression by removing a plug and then take a guess on how tight to do the manuals up.

[Wicky]

Never had to remove carbs when I did it... airbox yes. Timing done on basis of rear pot cam and alternator cover off - tighten finger tight and back off, rotate so many degrees and do front pot. Job done and still working 40,000 miles later.

PS OT Saw TV antiques prog on history of Leyland (saw it as your location) motors and it stemmed from delux steam powered lawnmower



Carry on

[sirch345]

It's not impossible to fit manual CCT's without removing the front cam cover. However I would say removing it would be the safer option, also (as you mentioned) it's easier to make sure the cams are in the right position, and you can measure the amount of free play in the cam chain as Karl (VTRDark) shows in his very good guide,

Chris.

[Chris58]

Last time I adjusted mine I tightened it lightly snug then backed it out about a 1/4 to 1/2 turn. When I took it apart it seemed perfect to me.

Pretty sure you'd want to position the flywheel at FT while doing the front and RT while doing the rear..I can't see how it'd get out of time.
Sounds like fact to me... but not the best way.

[tony.mon]

Last time I adjusted mine I tightened it lightly snug then backed it out about a 1/4 to 1/2 turn. When I took it apart it seemed perfect to me.

Pretty sure you'd want to position the flywheel at FT while doing the front and RT while doing the rear..I can't see how it'd get out of time.
Sounds like fact to me... but not the best way.

You've missed something important.
Due to the four stroke cycle the crank has two FT marks line up and the cam rotates only once.

So you cannot tell whether you are at the correct FT without either removing the rear cam cover or, possibly, removing the carbs and observing whether the valves are open or closed by looking into the inlet tract.

Get the wrong one and it's all got to come apart anyway.

But then why would you want to go to the trouble of removing carbs when lifting the rear cam cover is easily accessible and only four bolts?

[AMCQ46]

It is possible to do without removing carbs and front cam cover, but because there are 2 TDCs for each cylinder (and both line up with the FT or RT marks) you need to know you are on the compression TDC where the cams are not pressing on the valve springs.. To do this you either need to remove the rear cam cover and look at the valve position, or measure the pressure or airflow in the cylinder to be sure you are in the compression stroke.

I am sure there are ways you could measure compression, but as the rear cam cover is easy to get to and only 4 bolts, why would you mess about with a less precise solution?

Setting the tension on the MCCT without removing the front cover is fairly easy, and that is a big timesaver as the front cam cover is more tricky to remove.

When you are setting the rear tensioner, you wind it in as hard as you can with your fingers, and then count the number of flats you need to back off to get the required slack on the chain (refer to the guide in workshop section for correct free play) and note down this number.

Now rotate the crank to the FT mark, making sure you follow the instructions in the guide for the correct direction and the correct angle to rotate.... So now you will be on the correct, compression TDC for the front.

So now you remove old CCT and fit new manual. Again go to max finger tight as your baseline.... Now you back out the mcct by the same number of flats that you did on the rear..... You will now have the correct slack on the cam chain.

Job done ...

But taking this shortcut will mean you can't check if the front cams have been set 180deg out or if they have jumped a tooth, so if the bike is not running as strong as it should, then you should do it the long way and remove the cam cover to check all the alignment marks

[TaxiDriver]

And as I have to check the valve clearances there is no easy way for me I'm afraid.

[Chris58]

Last time I adjusted mine I tightened it lightly snug then backed it out about a 1/4 to 1/2 turn. When I took it apart it seemed perfect to me.

Pretty sure you'd want to position the flywheel at FT while doing the front and RT while doing the rear..I can't see how it'd get out of time.
Sounds like fact to me... but not the best way.

You've missed something important.
Due to the four stroke cycle the crank has two FT marks line up and the cam rotates only once.

So you cannot tell whether you are at the correct FT without either removing the rear cam cover or, possibly, removing the carbs and observing whether the valves are open or closed by looking into the inlet tract.

Get the wrong one and it's all got to come apart anyway.

But then why would you want to go to the trouble of removing carbs when lifting the rear cam cover is easily accessible and only four bolts?

Yea that's true, I forgot about that. Well you'd have a 50% chance

[BrianC]

We'll give it the full treatment Graham(taxidriver)

Might as well give it the works mate

Mailed you about saturday ?

[sirch345]

As pointed out by Tony and Al, being on the compression stroke when lining up the "FT" or "RT" marks is the crucial point I agree,

Chris.

[BrianC]

We will be following the excellent guide from here!!

I have used it twice with no problems

[E.Marquez]

Firstly I absolutely agree with the majority here, Remove both valve covers, even do the Zip tie sprocket deal if it is concern..
When I install MCCT's on a SH, I remove both cam covers and zip tie the chain..for me it is a time saver, in that it takes only a few minutes extra to do so, but it might save me an hour or more of retiming the cams.
It also means I dont have to remove the timing plug,,,as I can see the cam lobes and just rotate motor until there are where I won’t them.

BUT, It is not that hard at all to get a cylinder to TDC on compression stroke by just removing spark plugs, and both side cover plugs.

I do it this way many times a month on bikes in general, and have done it on my SH a few times.

[fabiostar]

both cam covers off for me aswell, for all the time it takes and at least it takes any guess work out of it.