Lack of power and noise after cct replacement

[chemomche]

I have just rebuilt the engine after front cct failure. Replaced 2 valves, new valve seals, valve clearance set, put manual ccts(OEM to manual).
The bike started easily, but after a ride i notice lack of power all over the rev range. Then i balanced the carbs and the bike was better. However, there is a noise - something like chain touching something at every rotation. It goes with the revs.
I tried to adjust the ccts, but the "finger tight" thing is hard to achieve as soon as i can make 2-3-4 turns finger tight. I tried to adjust the by the sound of the chain, but when static(the bike on sidestand) i can`t hear any difference in the engine noise no matter how many turns i make back or foreward. Neither the rear nor the front cct.

Now the bike still has this sound plus it lacks power after 5k. I think it does it after warmed up, but hever tried to go after 5k when the engine is cold.

What can it be?Is it ccts - too tight, too loose?
Can it be wrong timing - the engine roteted freely before i put it back together, but this does not mean i have not skipped a tooth.

Can i adjust the ccts by cam chain slack?They were adjusted this way by 7mm chain slack between the cam wheels, but after the first ride i tried the finger tight thing an may be mess the adjustment and i cannot remmember if there was the noise at this first ride so the bike just needed the carbs balanced and after that i make the ccts too tight and the problems acured.

I plan to remove the head covers, check the timig again, adjust the ccts at 7mm chain slack.
Any other suggestions?
BTW can you give some more info about measuring cam chain slack?

[AMCQ46]

Loss of power sounds like you have set the bike up with the cam timing 180 degrees (crank degrees) out on one cyl, this results in a loss of power above 5000 rpm. You should turn 1 1/4 engine revs from the rear tdc setting round to the front cyl.

Best way to set tension if you can't hear a difference is with cam covers off and measure the 7mm total slack (ie combined up and down motion =7mm). Too tight and it screaches on start up due to metal to metal contact.

Read and re read the instructions in the workshop kniwledgebase section

[chemomche]

Loss of power sounds like you have set the bike up with the cam timing 180 degrees (crank degrees) out on one cyl, this results in a loss of power above 5000 rpm. You should turn 1 1/4 engine revs from the rear tdc setting round to the front cyl.

i did it the same way - rear cylider tdc to replaced rear cct, then 1 1/4 counter clockwise till "T F" mark showed and put the front cams in place, and i remember that the rear cylnder inlet valves were open when i did the front cylinder timing

Best way to set tension if you can't hear a difference is with cam covers off and measure the 7mm total slack (ie combined up and down motion =7mm).

Yep, did the same - 7mm total slack with the the chain covers off. but may be messed it up afterwards with the hand tight thing

PS The bike starts very easy, if it matters, and the lack of power is noticable at 3th and upper gears.

[AMCQ46]

You also sure you have got the vac pipe for the fuel tap on the correct nipple? Should be on the one at the back, not the one at the bottom. That was the problem with the last forum member complaining of power issues after CCT replacement

[chemomche]

my bike uses a fuel pump and the pet rock do not need the vacuum tube
i balanced the carbs and both vacuums are set in place, but i will check them again

[AMCQ46]

is the fuel pump working?

[lloydie]

It does sound like fuel starvation to me .
Also is the airbox seated correctly ?

[VTRDark]

lacks power after 5k

Classic timing out 180 degrees. But do check the vaccum is on properly first as we had one with simmer symptoms recently that turned out to be that.



And I would not rely on the feel method in fact if you overtighten by feel it could cause damge while the bike is running. When you adjust the timing for the front cylinder starting from the rear set up at RT turn 1 1/4 turns anti-clockwise. You will see the FT pass the window once and when it come round the second time you should be at 1 1/4 turns. If you set them while it on FT the first time you see it then that would be 180 degrees out.

(:-})

[chemomche]

is the fuel pump working?

yes, the pump is working - checked
air box - all the plugs on their places
the pet rock is on..never touched it, and the fuel is runing freely

i will check the timig ones again and the ccts set by chain slack as he head covers will be off

PS 7mm slack when the engine is cold right?
a cannot do it warm as till i get to the cam it will be cold again

[VTRDark]

Yep when cold. the 7 mm play would be taken from the centre off the chain between the two cam sprockets, so you will need to remove the chain guides. Also the play is the air gap that the chain moves up and down. I done mine 9mm play from the centre of the chain link up and down.

(:-})

[chemomche]

Also the play is the air gap that the chain moves up and down. I done mine 9mm play from the centre of the chain link up and down.

(:-})

wow, there is the thing...i did mine 7mm play, measuring the chain pin travel up and down, is there a difference
why you done it 9mm?or 9mm ot the center of the chain equals 7mm air gap??

[VTRDark]

There's probably slightly more than 2mm difference but not a lot, and I would rather have the chain slightly on the loose side than be too tight and adding stress wear and tear to my bearings and other engine components. I got both chains spot on 9 from pin to pin and have no rattles and have never had to make any adjustments.

One other thing you should do is put some silicone, threadlock or gasket seal along the thread on the tensioner so it goes right inside the orifice along the thread. This serves two purposes, 1 it stops any oil leakage that may crawl along the thread and 2 it act's as a brake to stop the cct unwinding rapidly if the locking bolt happens to come loose at any stage which it shouldn't if done up tight enough and sealant/threadlock is used, which takes me back to the first reason as oil seeping through would aid to loosening the locking nut over time.

(:-})

[chemomche]

Yep, i thought of that - i put blue locktide on the bolt threads(both 8mm bolt and two 6mm's)
and also put a drop of casket silocone on the 6mm bolt heads and the cct lock nut so, if there isa any movement i will notoce it by the cracked silicone drop

[tony.mon]

Timing out 180- re-do and follow the Sirch instructions to the letter.
Rear first, then one and a quarter turns anti to get to the fornt tdc.

[chemomche]

Saturday evening i opened the cam covers. The from cylinder exhaust timing was 1 tooth off.
Got it right and put the bike together. It was 2:00 AM so it was no time to test it plus the silocone had to dry out.
The next day tried it, but still 3rd gear 5k was a flat spot.
Removed the carbs and fund the chocke cables was not returning right, or so i think. Balanced the cars once again, they needed same adjustment. Put everything back together again an i think the bike runs fine now. 3rd gear over 5k. Can`t tell if it is the best, test it in the town, but seem ok.