MtnEX
09-28-2008, 12:20 AM
I thought I would try my luck here since I'm not getting anywhere much in the 400EX section.
My problem is that on the first start of the day, my quad fires... but then dies several times before it will stay running. Then once hot, the idle speed is much higher than cold.
I had a pipe, filter and jetting done...
Full Yoshi, K&N in stock box with lid, unknown jetting.
It was showing rich on all circuits when reading the plug.
But it was starting great.
I took the carb off to see what the jetting was.
Stock 38 pilot, several turns out.
155 main jet
Needle clip in 3rd position down.
I also found that the needle holder the main screws in was not turned in all the way. It was turned some of the way in, then set with the locknut.
I screwed the needle holder all the way in, did the locknut, put the 155 main back, then lightly seated the pilot screw and backed out 2 1/2 turns.
It's ran like this since I put it back together. I even backed the pilot screw out 1 more turn to 3 1/2. It still fired and died, yet was rich enough to be able to smell richness in the exhaust.
I'm at 2 turns out now and it still does it. I think stock is one turn out, but I'm not stock. I'm very frustrated with trying to get it right because I don't have the Motion Pro tool to "hot tune" the pilot screw and idle screw together while the engine is hot.
DO THESE BIKES HAVE TO BE RICH ON THE PILOT CIRCUIT TO START WELL?
If so, I could back it out to like 4 turns or more and see if it goes back to it's old ways... and if so, go to a larger pilot if that's what it needs.
Help... I'm lost :mad:
My problem is that on the first start of the day, my quad fires... but then dies several times before it will stay running. Then once hot, the idle speed is much higher than cold.
I had a pipe, filter and jetting done...
Full Yoshi, K&N in stock box with lid, unknown jetting.
It was showing rich on all circuits when reading the plug.
But it was starting great.
I took the carb off to see what the jetting was.
Stock 38 pilot, several turns out.
155 main jet
Needle clip in 3rd position down.
I also found that the needle holder the main screws in was not turned in all the way. It was turned some of the way in, then set with the locknut.
I screwed the needle holder all the way in, did the locknut, put the 155 main back, then lightly seated the pilot screw and backed out 2 1/2 turns.
It's ran like this since I put it back together. I even backed the pilot screw out 1 more turn to 3 1/2. It still fired and died, yet was rich enough to be able to smell richness in the exhaust.
I'm at 2 turns out now and it still does it. I think stock is one turn out, but I'm not stock. I'm very frustrated with trying to get it right because I don't have the Motion Pro tool to "hot tune" the pilot screw and idle screw together while the engine is hot.
DO THESE BIKES HAVE TO BE RICH ON THE PILOT CIRCUIT TO START WELL?
If so, I could back it out to like 4 turns or more and see if it goes back to it's old ways... and if so, go to a larger pilot if that's what it needs.
Help... I'm lost :mad: