Why won't it run??

[pc kawi148]

I have a 2003 KX125, I just put a new top end in it, and cleaned the powervavle thoroughly. It broke in fine, had two days of easy riding on it, now I just started to really get on it. I am running Klotz R 50 at 32:1 at first now I am at 40:1. When I was running it at 32:1, it seemed like it was always loaded up, even after wot throttle for about 200 yds, then it would clear out. It sounded all broken up. Yesterday, I put a brand new plug (4th one) in it, it ran fine for 10 min., then i was coasting down an alley way, and it started to die so i gave it a little juice, it bogged real bad and died. So i cleaned the spark plug off, switched to 40:1, and it starts easily, kinda loaded up, I try to clear it out, then it just bogs and dies. I can just keep cleaning the sparkplug off and it will keep starting.

Please Help

 

[CROGGR]

I have a 2003 KX125, I just put a new top end in it, and cleaned the powervavle thoroughly. It broke in fine, had two days of easy riding on it, now I just started to really get on it. I am running Klotz R 50 at 32:1 at first now I am at 40:1. When I was running it at 32:1, it seemed like it was always loaded up, even after wot throttle for about 200 yds, then it would clear out. It sounded all broken up. Yesterday, I put a brand new plug (4th one) in it, it ran fine for 10 min., then i was coasting down an alley way, and it started to die so i gave it a little juice, it bogged real bad and died. So i cleaned the spark plug off, switched to 40:1, and it starts easily, kinda loaded up, I try to clear it out, then it just bogs and dies. I can just keep cleaning the sparkplug off and it will keep starting.

Please Help

Quit messing with the oil ratio and just jet your bike properly. Your air to fuel ratio is too rich, not your oil to fuel ratio! You will need to drop at least one size on the pilot and raise the clip one position and possibly also drop the main a size. Do one thing at a time starting with the pilot jet and move on from there.

 

[J1mMy]

Sounds like it is jetting related,is it stock jetting?

 

[pc kawi148]

Yes, it is stock jetting. It has ran fine for the last 2 years. The only difference is that this time I used wiseco. The sparkplug is all wet when i pull it out. I have a main jet for it that is one step leaner.

 

[pc kawi148]

I rejetted it and the plug is still wet. My stock plug is a BR9ES, I use a BR8ES, is it alright if I go to 7?

 

[sick 96 250]

i hope you didnt just put in the 1 step leaner jet and think that you re-jetted it? It may take several different size jets to get the right set-up. Have you also cleaned out the carb real good and make sure your floats are set correctly? When you say wet is it oily wet or gas wet? Did you get coolant in the bottom end when you re-did the top end? Most likely the bike wont start but thought i would ask

 

[nikki]

Did you run the Klotz R 50 before the top end job? Did it run fine before the top end? Are you sure you put the powervalve back together correctly? Does the bike idle okay (if not, you might have to rejet with the pilot jet and/or air screw). Does the bike run okay 1/4-1/2 throttle - if you, you might have to adjust the clip on the needle. If the problems are 1/2-full throttle, then that's main jet.

On plugs, I would NOT go to a BR7ES if your bike ran fine with BR8ES plugs before the top end job. The 7 is a very hot plug for a 125, and you'll put your bike at risk. And if it ran fine before, you have another problem from the rebuild. Someone will correct me if I'm wrong, but using a different piston (like Wiseco vs. stock) shouldn't have this type of effect on a bike. The only thing I did differently with Wiseco pistons (when I rode 125's) is use a small drill bit to make the breather holes a little bigger for better lubrication/cooling, but that shouldn't have anything to do with your problems.

Have you checked the coolant? Is it still full, and how does it look? What ratio did you mix your gas before? Are you doing the same now? Is everything okay with your reeds? Is your air filter clean and properly oiled? Did you play with the carb during rebuild? Are any breather hoses kinked/clogged from rebuild? Is the cylinder and head on and torqued according to specs? Are there any gaskets/o-rings that might be damaged/pinched?

Lots of questions - but these are some things I'd check/think about.

 

[pc kawi148]

The bike is put together properly, I have a bit of OCD when it comes to fixing things. This is the first time I used the koltz. I am going to go one clip leaner on the needle. 1/2 throttle down is fine, it never did idle so, I am going to screw with the needle and get another plug. I also drained and refilled the oil and drained all the coolant before the rebuild process. This is also the first time I messed with a carb, but I catch on to things quickly.

Thanks

 

[MikeT]

I would stay with 32:1 ratio and go back to the oil you used to use if it wasn't producing a wet plug. I would recommend that you continue to re-jet the bike so that it runs properly because that seems to be the cause of your problem. If you want to change oils, I use the Maxima SuperM with good results (in a properly jetted bike) ;)

 

[pc kawi148]

I went one clip leaner on the needle and adjusted the air screw and idle and now it is running fine. Thanks everybody.