This is on a Honda '74 - z50, I have the E22 race head and up the cc to 72cc with a piston change and a full race cam with 6mm cam lift. I added a new carb from 17mm to a 20mm for more power.(Speed hungry) When I go and give it full throttle the engine just bogs down like it's going to die. This happens in every gear plus neutral. I played with the adustments currently on the carb and found nothing to help.
If you don't give it full throttle you can certainly feel the difference in power from the old carb. Any ideas would be great. Oh I live in Maryland. I've done all the mechanics on the bike so just give to me straight.
If it is a jet issue how do you know which size jet to use?
2007-11-23 03:15:21 · 4 answers · asked by Nobody_Here 4 in Cars & Transportation ➔ Motorcycles
Try going with a slightly smaller main jet. Sounds like it is getting too much fuel at WOT.
Is it blowing black smoke like it is running rich? You say it is running great as long as you don't open it up, so I would guess that your air/fuel mixture screw is close on, but your main jet is just too large...
2007-11-23 03:21:35 · answer #1 · answered by boogie_4wheel 7 · 0⤊ 0⤋
Sounds like a lean condition. Try going back to old carb and see if problem still exists. If it runs OK on old carb, it indeed may be jet size problem in new carb.
When re-jetting, I use trial and error. If you are careful, jets can be drilled to next largest size(s) using small drill sets available at MSC Industrial supply. Check out drill sizes #1 through #80. There are charts that indicate how large a hole these small bits make. For example: # 58 bit will make a 0.0420 hole.
Knowing what size your jet is will help as a starting point. You will probably need something in or around #55. Use appropriate pin vise as jets must be carefully drilled out by hand and burr free. Use a jewelers loupe to inspect.
2007-11-23 12:01:04 · answer #2 · answered by russellj_1998 2 · 0⤊ 0⤋
Contact me for a carb trouble shooting guide.
It will explain what adjustments to make to repair running conditions.
With the guide, you might be able to figure it out for yourself.
2007-11-23 14:43:14 · answer #3 · answered by guardrailjim 7 · 0⤊ 0⤋
also have a look at your air cleaner
2007-11-27 09:11:25 · answer #4 · answered by VTR 3 · 0⤊ 0⤋