Engine after rebuild

[MotoBK]

Lack of Topend power after rebuild and reeds.

I rebuilt the topend on my 2001 220, I also installed a set of Boyesen dual stage reeds. I have heat cycled the engine three times. I heated it up once more, then took it up a constant fire road climb for 20 min to finish break in. I just took it out around the block a couple of times, and I have found that the high RPM area seems to be lacking. Not sure if I need to change the jetting, with the addition of the Boyesen reeds? I am in stock setup as far as jetting goes right now. Let me know if this is normal..........

 

[julien_d]

Did you check the power valves when you had it apart?

 

[MotoBK]

Yes, I did not take them all the way apart, but I cleaned them, and remove the little bit of carbon on them. The flaps all moved pretty well.

 

[sr5bidder]

the reeds come with instructions on jetting...sorry for you with the 220 topend power...good luck

 

[mechanos]

Try dropping the main jet down one size, my 220 falls off on top if the main is too large. I run a 142 in summer, winter is a 145. Good luck.

 

[MotoBK]

I took it out today to ride, and played with the air screw. I usually have it 1.5 turns out. I turned it out to 2, and it ran a little better on the top....then I went to 2.5 out and it had a hard hitting mid to top. I know that this is not acceptable for the air screw....so does this mean the I need to go with a 142 main to get things back in line? Any help is appreciated!!!

Thanks!!

 

[julien_d]

2.5 turns on the airscrew is the generally accepted limit though. If you want to cut back on that a bit, you'll need to go to a smaller pilot jet. Changing the main jet size will have little to no bearing on your airscrew adjustment.

 

[MotoBK]

Any idea why this would effect the top end power then....I thought that the pilot was for the beginning of the rpm range?

 

[julien_d]

It has nothing to do with rpm range, but everything to do with throttle position. Unless you're running around WFO all the time, the main jet really does not make as much difference as the pilot, needle, and airscrew. I'd suggest playing with the needle. Set the airscrew where you get the best throttle response. Raise the clip a notch and try it, then lower the clip a notch and ride it. Note the difference....