SuperHawk Forum

SuperHawk Forum (https://www.superhawkforum.com/forums/)
-   Technical Discussion (https://www.superhawkforum.com/forums/technical-discussion-28/)
-   -   Lack of power and noise(cam chain may be???) after cct replacement (https://www.superhawkforum.com/forums/technical-discussion-28/lack-power-noise-cam-chain-may-after-cct-replacement-29303/)

chemomche 10-14-2012 11:00 PM

Lack of power and noise(cam chain may be???) after cct replacement
 
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:confused:. 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?

Caffeine 10-15-2012 12:51 PM

"lacks power after 5k when warm" I had the exact same thing!! 1 tooth off on the intake valve! fixed it perfectly.. and to be honest.. I moved it one tooth and to me it still looked like it was off the other way.. but the bike runs perfect!

in the end,I adjusted the cam chain as tight as I couldby hand and I was told it often takes a wrench to get it tight enough, but its working well, so I'm not touching it.

aja 10-15-2012 02:47 PM

7mm, or 1/4 inch, is the recommended start point. I never touched mine after that.

Sounds like a timing issue though.

zxbud 10-15-2012 07:59 PM

Revs
 
If the valve clearance is too tight it won't rev high either. I like them on the loose side which renders more off idle torque. The downside of too much off idle torque is the grips can get jerked out of my hands when I carelessly pull away from a u-turn. It happened the other day and I won't be careless again. :eek::eek::eek:

chemomche 10-15-2012 11:02 PM


Originally Posted by zxbud (Post 343339)
If the valve clearance is too tight it won't rev high either. I like them on the loose side which renders more off idle torque. The downside of too much off idle torque is the grips can get jerked out of my hands when I carelessly pull away from a u-turn. It happened the other day and I won't be careless again. :eek::eek::eek:


the valves are set to 15 IN and 30 EX

7moore7 10-16-2012 08:12 AM

I'd guess the chains are too tight. And by guess, I mean I've always done it the way aja said. I could never trust myself to do it by feel or noise, so set the chain play to 1/4" total. To check this as well as check the timing, you'll have to remove the valve covers.

I'd take the covers off. Check the timing by lining it up at TDC front and rear and make sure the intake and exhaust marks on the sprockets are in line. Then, remove the little piece that covers the cam chain between the cam sprockets. Three bolts per cylinder (one small and two long ones). The chain in between the sprockets is the amount of play that you're measuring- 1/4" or so.

chemomche 10-22-2012 04:16 AM

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.

chemomche 10-30-2012 06:02 AM

Still issues

Starts easy, no stalling, warking pretty much perfect at idle. Low range is nice up to 5k.
Removed the carbs again and found that the front carb choke was stuck open, closed it and and tried the bike again. The one of the two small carb vent filters that are in the air box was torn apart, so i change is with some foam, and put samo ot the other too. balanced the carbs again too(this time with the air box on).
Better performance but still not best. The tach is smooth to 6-7k then the bike hesitates a little, then goes to 8-9k ant i can feel power, but as i change the gear and the rpm drok to 7k there is hesitation again, just for a second and the bike pulls again. The bike did 210km/h that way, feeling the hesitatino each time i changed the gear, and i run out of road.
May be just result of riding 20km with front choke open, may be not.

One other thing - the big popping from the exhausts when deaccelerating is back. I had it before the cct failure. At that time i though it was because the link pipes and the cans are not connected well, there is 5mm space. Then when i stipped the bike to get the front head fixed i noticed the rear cylinder vacuum line was left free, not connected to the pet rock, and thought that it was causing the popping, because when i started the bike after cct fix the popping was gone.
Well now it is back and i do not know if it is for good - on one hand before the cct failure the bike was poppong but runing well, on the other the popping is no good and my be result of lean mixture, moreover now the vacuum line is in place.

Any suggestions?What could cause this hesitation at 7k?
Can it be blocked fuel cap vent?
Can it be the foam i put on the carb vent holes(those in the air box, under the air filter)?
Lean mixture or not properly tuned carb for the fixed front head?
Something else?

chemomche 11-13-2012 12:26 AM

Hi, little update - i did shim and slide mod from the superhawk forum.
Bike runs pretty well, execpt from some electrical issues -the xenon bulb turn off from time to time and i have to restart it adn my tacho is a bit crazy on bumps.
Here is a short video.
(you can see at 14th second how i restart the headlight)


All times are GMT -7. The time now is 12:33 PM.


© 2024 MH Sub I, LLC dba Internet Brands