Jump to content

Mcct install TDC instructions ambiguous

Recommended Posts

Some instructions say tdc needed, some say its not needed. Some say take top off, some say just put T line in inspector hole. Some say adjust crank normal way, others say adjust the other way.

As i can tell, tdc is needed to take tension off chain so it doesnt jump a notch once acct removed. Can this risk be minified by removing acct slowly/gently?

Basically im looking for the easiest mcct install that is still reliable. Taking cover off is beyond my comfort level and will let mechanic do it. Would be nice not to need.

Share this post


Link to post
Share on other sites

Ya you can do it that way, but if you jump a tooth and get out of time shit gets real quick.

There is a small inspection plug on top of the flywheel cover... just Pull that bolt off (think its a 8mm hex key) and you can see the flywheel. If you don't want to open anything else put the bike in gear and bump it slowly until you see the timing mark via the inspection hole. Takes 30 seconds and gives you ease of mind. 

Note: make sure to bump it slow or you'll overshoot TDC. May take a few trys your first time but you'll get it eventually. The mark is a thin line with a T on one side of it. The line should be in the center of the view port. Hollar if you need some pictures 👍👍

Edited by RC_ichard
  • Like 1

Share this post


Link to post
Share on other sites
53 minutes ago, RC_ichard said:

Ya you can do it that way, but if you jump a tooth and get out of time shit gets real quick.

There is a small inspection plug on top of the flywheel cover... just Pull that bolt off (think its a 8mm hex key) and you can see the flywheel. If you don't want to open anything else put the bike in gear and bump it slowly until you see the timing mark via the inspection hole. Takes 30 seconds and gives you ease of mind. 

Note: make sure to bump it slow or you'll overshoot TDC. May take a few trys your first time but you'll get it eventually. The mark is a thin line with a T on one side of it. The line should be in the center of the view port. Hollar if you need some pictures 👍👍

Thanks Rcicard, this method sounds perfect!

Share this post


Link to post
Share on other sites

I think the biggest reason is so you can physically see when the chain is snug so you have a good starting point. The manual tensioner can do far more harm than the original if not set correctly. I played with mine for a awhile before it was right. Remember , rocks in a metal coffee can sound. All you want is for that sound to stop. Don't give it a 1/4 turn extra for luck. You CAN over tighten the chain and make the normal sound less noisy. That of course is bad, very bad.

 

Sent from my XT1650 using ThumperTalk mobile app

 

 

 

 

  • Like 4

Share this post


Link to post
Share on other sites
3 hours ago, ohiodrz400sm said:

I think the biggest reason is so you can physically see when the chain is snug so you have a good starting point. The manual tensioner can do far more harm than the original if not set correctly. I played with mine for a awhile before it was right. Remember , rocks in a metal coffee can sound. All you want is for that sound to stop. Don't give it a 1/4 turn extra for luck. You CAN over tighten the chain and make the normal sound less noisy. That of course is bad, very bad.

 

Sent from my XT1650 using ThumperTalk mobile app

 

 

 

 

Thanks for valuable details!

  • Like 1

Share this post


Link to post
Share on other sites
On 9/2/2017 at 5:26 PM, ohiodrz400sm said:

I think the biggest reason is so you can physically see when the chain is snug so you have a good starting point. The manual tensioner can do far more harm than the original if not set correctly. I played with mine for a awhile before it was right. Remember , rocks in a metal coffee can sound. All you want is for that sound to stop. Don't give it a 1/4 turn extra for luck. You CAN over tighten the chain and make the normal sound less noisy. That of course is bad, very bad.

 

Sent from my XT1650 using ThumperTalk mobile app

 

 

 

 

I just put a Thumpertalk MCCT on my 2001 E model. i took the valve cover off to install. The instructions said nothing of this. The adjustment procedure that came with it was roughly, "tighten the tensioner finger tight, rotate the engine, til it is loose again. Do finger tight to take up the slack.  (they said not to force and I did not.) Then back it off 1/4 turn" . . .  So the engine was quiet . . . but looking at what everyone else was saying, I had a nagging suspicion that it may have been too tight.  So I tried the "rocks in coffee can method". 

The thing that gets me is the noise kind of changes. There is a rocks in coffee can sound, then there is just kind of a knocking as I adjust. Finally I make the knocking go away. As it turns out, I backed off from what the instructions said . . . by almost 3/4 of a turn. 

Did you encounter the coffee can to knocking transition in the adjustment? How did you come to peace that you had done the right thing? Is there any harm in running it a little loose?

Two stroke are so much easier!!

 

 

     

Share this post


Link to post
Share on other sites
I just put a Thumpertalk MCCT on my 2001 E model. i took the valve cover off to install. The instructions said nothing of this. The adjustment procedure that came with it was roughly, "tighten the tensioner finger tight, rotate the engine, til it is loose again. Do finger tight to take up the slack.  (they said not to force and I did not.) Then back it off 1/4 turn" . . .  So the engine was quiet . . . but looking at what everyone else was saying, I had a nagging suspicion that it may have been too tight.  So I tried the "rocks in coffee can method". 
The thing that gets me is the noise kind of changes. There is a rocks in coffee can sound, then there is just kind of a knocking as I adjust. Finally I make the knocking go away. As it turns out, I backed off from what the instructions said . . . by almost 3/4 of a turn. 
Did you encounter the coffee can to knocking transition in the adjustment? How did you come to peace that you had done the right thing? Is there any harm in running it a little loose?
Two stroke are so much easier!!
 
 
     


I stick with eliminating the rattle sound plus just a bit more (1/8 turn ish) to migate the knock. It's supposed to be somewhat noisy.

Share this post


Link to post
Share on other sites

That is good info . . .  it sounds like it is better to run them a bit loose rather than too tight. Interesting . . . I saw another guy talking about how easy it is to screw up with MCCT.   

 

Thanks

Share this post


Link to post
Share on other sites

The miss-understanding of TDC for cam chain tensioner removal continues. TDC refers to top dead center of the piston (when the piston is at the top of A stoke).  There are 2 TDC occurrences per combustion cycle of a 4 stroke motor. TDC compression on the power stroke when the valves are all closed and TDC of the exhaust stroke after a combustion cycle when the valves are all open due to valve over-lap timing.  The only place you want to remove the cam chain tensioner (auto or manual) is when the valves are all closed - TDC compression.  The way to know that is to take the motor top cover off and look at the valves.  Or, if you are an experienced mechanic, and can feel TDC on the compression stroke. 

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, Noble said:

The miss-understanding of TDC for cam chain tensioner removal continues. TDC refers to top dead center of the piston (when the piston is at the top of A stoke).  There are 2 TDC occurrences per combustion cycle of a 4 stroke motor. TDC compression on the power stroke when the valves are all closed and TDC of the exhaust stroke after a combustion cycle when the valves are all open due to valve over-lap timing.  The only place you want to remove the cam chain tensioner (auto or manual) is when the valves are all closed - TDC compression.  The way to know that is to take the motor top cover off and look at the valves.  Or, if you are an experienced mechanic, and can feel TDC on the compression stroke. 

Yeah, looking back at what I originally posted, I could see how you would think that I misunderstood. What i did not say, was that I did find TDC, with the cams at 10 and 2 o clock, and I removed the ACCT then. . As you said also, if  you really know what you are doing, you can listen to the engine as you rotate it. You can hear the intake impulse at the carb. Next TDC is with both valve closed, although there is a compression release.

Being that this is a 2001, I wanted to check my valve clearances, so I wanted to remove the valve cover anyway. They were in spec. 

My confusion was the tension adjustment procedure . . . . .  you can see from my original post what my issue was.  

I am a 2 stroke guy from way back.        :)

Thanks

  • Like 1

Share this post


Link to post
Share on other sites
6 hours ago, Fourstrokenewb said:

Yeah, looking back at what I originally posted, I could see how you would think that I misunderstood. What i did not say, was that I did find TDC, with the cams at 10 and 2 o clock, and I removed the ACCT then. . As you said also, if  you really know what you are doing, you can listen to the engine as you rotate it. You can hear the intake impulse at the carb. Next TDC is with both valve closed, although there is a compression release.

Being that this is a 2001, I wanted to check my valve clearances, so I wanted to remove the valve cover anyway. They were in spec. 

My confusion was the tension adjustment procedure . . . . .  you can see from my original post what my issue was.  

I am a 2 stroke guy from way back.        :)

Thanks

Exactly how i do it , i remove air filter , listen to suction , next time you see  line in window is TDC 

Share this post


Link to post
Share on other sites

Removing head is even better , good time to check my valve clearance  . Sorry , valve cover .

Edited by habs
Correctio
  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×