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Posted

Hi, my son has a TZR 125 with 4JB motor. He just recently bought the bike. The bike used to run reasonably well but tops out at about 65mph. I'm sure it can do better than that! lately the bike wont rev to full revs in any gear but gets to about 10000 rpm and then starts cutting back. No matter what we do we cannot get it to rev properly. Checked the carb, checked the power valve settings, spark plug etc. No Joy. also noticed that the power valve only starts to open at 9000 rpm but does open fully if you can get the bike to rev. Any ideas?

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Posted

im having similar problems on my aerox100 :( if you find out what is causing it let me know so i can tell the garage on what do sort out thanks :)

Posted

Hi, my son has a TZR 125 with 4JB motor. He just recently bought the bike. The bike used to run reasonably well but tops out at about 65mph. I'm sure it can do better than that! lately the bike wont rev to full revs in any gear but gets to about 10000 rpm and then starts cutting back. No matter what we do we cannot get it to rev properly. Checked the carb, checked the power valve settings, spark plug etc. No Joy. also noticed that the power valve only starts to open at 9000 rpm but does open fully if you can get the bike to rev. Any ideas?

It is restricted like that so you dont blow the engine.

OR are you saying the bike wont rev at all now ?

Posted

It is restricted like that so you dont blow the engine.

OR are you saying the bike wont rev at all now ?

i think what he means is the revs have been restricted some point after it went to the garage and now wont rev to a suitable point where its too sluggish and too low to pick up decent speed i think it might be your powervalve that might need tuning?

Posted

FIXED!!!!!!

Two days of checking and testing everything and eventually solved the problems. This may help other TZR owners as I did a lot of searches and found a lot of owners have similar problems. Bike now revs to 14000 tops out at just under 180km/hr.

PROBLEMS SOLVED:

1. Removed and checked power valve. Power valve was assembled incorrectly. There are two locating pins on the power valve and these had been aligned incorrectly. This way, no matter what the position of the valve it could NEVER be fully open.

2. Power valve was sticking when trying to open. Cleaned up all surfaces and valve now turns exceptionally easily. The power valve motor has very little power and cannot turn the power valve if it is the least bit sticky.

3. Reed valves. Incorrectly set and positioned upside down. The top set of reeds have a different clearance to the lower set.

4. Power valve unit set 180 degs. out. Valve was closing at revs instead of opening.

5. Bad electrics. Found the main power cable from the battery not giving fully voltage while riding. It was o.k. while the bike was stationary, but when riding there was a voltage drop that was affecting the CDI and the power valve operation. cleaned and tightened all connections.

After this bike runs well and just about pulls itself out of your hands when you hit the power band. I'd love to take it back to the guy who sold it to us for him to ride. I'm sure he thought he sold us a real lemon!! HA, the laugh is on him 'cause we got it at a real good price!

Hope this helps anyone with the same problems.

Posted

glad its sorted mate, might get the garage to clean my carb and service the carb properly as i think im on the same boat as you on my aerox100

Posted

FIXED!!!!!!

Two days of checking and testing everything and eventually solved the problems. This may help other TZR owners as I did a lot of searches and found a lot of owners have similar problems. Bike now revs to 14000 tops out at just under 180km/hr.

PROBLEMS SOLVED:

1. Removed and checked power valve. Power valve was assembled incorrectly. There are two locating pins on the power valve and these had been aligned incorrectly. This way, no matter what the position of the valve it could NEVER be fully open.

2. Power valve was sticking when trying to open. Cleaned up all surfaces and valve now turns exceptionally easily. The power valve motor has very little power and cannot turn the power valve if it is the least bit sticky.

3. Reed valves. Incorrectly set and positioned upside down. The top set of reeds have a different clearance to the lower set.

4. Power valve unit set 180 degs. out. Valve was closing at revs instead of opening.

5. Bad electrics. Found the main power cable from the battery not giving fully voltage while riding. It was o.k. while the bike was stationary, but when riding there was a voltage drop that was affecting the CDI and the power valve operation. cleaned and tightened all connections.

After this bike runs well and just about pulls itself out of your hands when you hit the power band. I'd love to take it back to the guy who sold it to us for him to ride. I'm sure he thought he sold us a real lemon!! HA, the laugh is on him 'cause we got it at a real good price!

Hope this helps anyone with the same problems.

Thank you very much. Just a little question 'bout 3d point. I didn't get it clear. what I need to do at this point?

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