02 special sport timing chain advice

[spreadeagle]

02 special sport, 36k , opened the timing cover and everything looks good. It has what appears to be a brass colored tensioner shoe. Not a heavy tension on the spring. I am assuming it’s not supposed to be a lot otherwise it would wear out quicker. I cannot detect any wear at all. Should I replace the related gasket/ seals and call it good?

[guzzisteve]

Right you are, enough tension to take out the slack but not wear out the pad. I put the stock one in my 86 Cal2 in 93 when they became available. It's now been almost 100K mi since and there is no noise or slack, still good. I'd swap seal w/brown one(viton) and a metal/rubber gasket(newer style) and button it up.

[spreadeagle]

Thanks

[bigbikerrick]

So on this year bike, there is no need to replace the chain tensioner with a valtek, or blade type of tensioner?
Is a hydro the same? I am just curious as to how this applies to my 03 aluminum.
Rick.

[guzzisteve]

Same inside the front cover, chain & sprockets. 93 models in US was the beginning of New World motor, no need to retorque heads(they are 35ftlbs) and came w/spring chain adjuster. The book still says 32 but even all new stuff comes 35ftlbs since 93. Do the 90*+90* on the studs and check it w/torque wrench, it's 35.

[pete roper]

So on this year bike, there is no need to replace the chain tensioner with a valtek, or blade type of tensioner?
Is a hydro the same? I am just curious as to how this applies to my 03 aluminum.
Rick.

I'm about to do the 'Final Update' on my Hydroturd Cali, just ordered head gaskets and valves because I think I'll give the top end a freshen up while I'm at it. It's done well in excess of 100,000km so I'm expecting to bung a new chain in it. I'm not sure if the Valtec type tensioner will fit in later Cali's? Isn't there a pin in the case used for the 'Flappy Foot' tensioner that gets in the way? Or did that happen with the advent of the 2V CARC series?

Pete

[guzzisteve]

Pete, The pin thing might be on the CARC's. There was a poster here that ran into the casting not being machined off on the side of the main which made the Valtek non usable. And you have to watch the length of the bolts so as not to interfere w/the crank flyweights. 

[Bill Owens]

If your hydro motor is like mine and at least one other on this forum, this is what fitshttp://www.mgcycle.com/index.php?main_page=product_info&products_id=5185

[Bill Owens]

This winter I am thinking of trying to marry the OEM tensioner with the Valtek blade and spring.

[bigbikerrick]

Steve, Pete, and Bill, thank you all for the info. I appreciate it!
Rick.

[John Croucher]

Your eyes are fooling you.  The wear you do not see cannot be seen unless the tensioner is removed.  The chain slack pushes the tensioner pad against the boss on the side of the crankcase stopping the flop from flopping further to the right (when facing the front of engine).  As you said, it does not apply any pressure to the chain, the chain flops to the left until the tensioner pad will not go any further and then eats the pad away.  If you take the snap ring off and take the pad out, you will see 1/8 inch or deeper grooves worn into it.  And yes, all this worn off pad goes through the engine. 

You will notice that the chain will easily move side to side with light pressure.  The chain is flopping around while running.  This flopping allows the cam to flop forward as the lobes past maximum lift.  You can feel this if you turn the engine over with the valve train all in place and a deep socket on the crank drive gear.  You will also see the chain flopping the tensioner while turning over the engine with a wrench. 

I would put a Valtek tension in the engine.  It is an easy job.  Getting the crank nut off the drive gear is easy.  Go to Harbor freight and by a set of "faucet wrenches", they are deep sockets.  One of the sockets will fit down the crank shaft to the retaining nut. Use another smaller socket on the faucet wrench and rattle gun to remove and install.

You will be surprised at how much smother the engine will run with out a sloppy timing gear setup.  I have read many post where people try to tune the slop out with the TPS sensor.  Chasing the wrong problem. 

Another thing to look at, the valve stems and rocker arms.  The oiling system does not lubricate the top of the valve stems good.  Causing the valve stem end to get a groove and the  rocker arm pad to flatten.  Oil comes into the rocker pin, out the end of the rocker and runs down the top of the rocker.  Being directed by flanges on top of the rocker arm.  It gets flung off before reaching the valve stem, causing them to wear.  If someone has a good idea on getting more oil to the valve stem end, let me know.   I used a fine hone to remove the notch in the valve and reshape the rocker arm pad.  Then you will need to adjust the valve clearance.  This is easy.  Just like on a solid lifter bike.  Bring the piston to top dead center on compression stroke.  Loosen the retaining nut, turn the screw in or out until you can turn the push rod with some resistance with your finger,  then turn the screw in 1-1/4 to 1-1/2 in, tighten the retaining nut.  Do all four valves. 

I have rebuilt several hydro motors.  Have one on the work bench now that I took apart over the last few days.  I scored a good find.  The cam and lifter recall is brand new.  Very few miles on the engine overall.    The head gasket was leaking oil on the front right and the base gasket was leaking on the front left. 

Another problems I see inside the head, a massive hot spot under the rocker support block.  The oil running off the rocker arms on to the support block flows back towards the intake valve and because the support block shields the top of the combustion chamber from getting cooling oil.  Leaving the very little oil to cool the top of the combustion chamber under the rocker support block.  Every engine top end I have taken apart has scorched oil on the head.  I am going to take a set of rocker support blocks and drill holes in the base to allow oil to flow through onto the top of the head.

[dguzzi]

Can you show us where you mean?  That's very interesting.

[John Croucher]

Can you show us where you mean?  That's very interesting.

I posted a video of the cam chain and tensioner on the Moto Guzzi Owners Club F.B. page. 

[Don G]

Another way to scope out how the tensioner is coping is to turn the crank clockwise a turn or so, then while watching the cam gear, slowly turn the crank counter clockwise, stop turning when the cam starts to move, how far did the crank turn before movement was detected at the cam? Should not be much, also at this point you can work the crank back and forth while watching the cam gear, you may be surprised at the amount of slop that is present. DonG

[dguzzi]

I posted a video of the cam chain and tensioner on the Moto Guzzi Owners Club F.B. page. 

  i meant the hot spot information, if its on Facebook its no help...(never go there)

[Chuck in Indiana]

  i meant the hot spot information, if its on Facebook its no help...(never go there)

I avoid it, too.

[John A]

I posted a video of the cam chain and tensioner on the Moto Guzzi Owners Club F.B. page. 

Good post, except the original post was about a non hydro. Doesn't make much difference on chain but the hot spot is interesting. I don't look at Facebook either
Another way to visually see the wear on the chain is to hold one end so the chain is horizontal and note the sag. Of course it has to be removed which leads me to the next question, where can you buy a better quality chain in bulk with a master link?

[guzzisteve]

If I remember correctly it's a BMW chain that MI was supplying w/master link. I have installed the thing and putting the clip on the master in the right direction was a total pain. You may want to check in Guzziology for info.

[John A]

If I remember correctly it's a BMW chain that MI was supplying w/master link. I have installed the thing and putting the clip on the master in the right direction was a total pain. You may want to check in Guzziology for info.

Thanks, Steve, forgot I have a Guzziology. Was the troublesome clip enough to just use a factory chain? I'm wondering if it's worth screwing around with. It'll be a while before I get that far into any of my big blocks

[Tom H]

Here are images of my hydro with the raised area under the stock tensioner. The one shows how the Valtec sits too high.





Tom

[guzzisteve]

There it is, save my brain.