Bike falls on its face in upper RPMS? Bigger intermediate jet? Woods 650 cam

[1997 Vintage]

So I got my 06 K9 tonight. First let me say this rides like a Cadillac compared to my old 04 Texas Chopper. Has a Woods 650 cam, head work all done by Sam Performance Cycles in Charleston, SC by previous owner. It starts fine, idles fine, runs good through slow acceleration and up to mid RPM range. Once I got it out on the highway and started to get on it a bit when I accelerate in the upper rpm range it sputters and falls on its face. If I back off the throttle it catches and goes. I am guessing this is from the intermediate jet being to small. I am putting a V&H BR exhaust on this weekend and will know what jets are in it then. Ideas? Am I totally off base?

I had same problem with SS super E shorty carb. Float level was set too low in my case.

 

[King Lear]

Put the new exhaust on tonight. The header bolts on the stock exhaust were finger tight. It like after they did the head work, cam and whatever other work they forgot to torque it down after. It runs much better, I haven't taken it out yet but will in the AM. It idles a little slower with the VH BR exhaust, I used the Big City Thunder baffles

 

[Griffit]

pull the carb bowl off, might be surprised what ya find, likely full of green corrosion..sounds like it needs cleaned

 

[Sven]

3 holes says... Main feeds idle, low feeds idle, air screw feeds idle. Does it start right up and idle? Yes. Not a dirty carb then.

 

[King Lear]

3 holes says... Main feeds idle, low feeds idle, air screw feeds idle. Does it start right up and idle? Yes. Not a dirty carb then.

Since I changed the exhaust, it fires right up and runs through the whole RPM range with no issues. I have some decel popping when downshifting. Only on deceleration though, no hiccups or backfires at idle or acceleration. They had the stock exhaust on with regular bolts with no threadlocker or lock washers. I took two of them off with my fingers. So between fixing the gap on the plugs, fixing the plug wires and putting on the new exhaust all is good!

 

[FrankBDPS]

Glad to hear you got it worked out. Good work.

 

[King Lear]

So it started doing it again, I took the bowl off, they had a 96 main jet in there, 36 intermediate and 40 air bleed. So I'm going to put in a 78 main and leave the rest. Wow a 96 main jet!

 

[King Lear]

all three

 

[mleach72]

all three
View attachment 77696

Yeah, a 96 main is way too big, even with the engine mods you have. The 40 air bleed is stock and is usually correct unless you are running open pipes. The intermediate seems a bit big too, but may be correct given the engine work. Most guys are in the 31-34 range on the intermediate. If everything seems fine below 3k rpms, just keep playing with the main jet. You will know when you hit the right one.

 

[King Lear]

Yeah, a 96 main is way too big, even with the engine mods you have. The 40 air bleed is stock and is usually correct unless you are running open pipes. The intermediate seems a bit big too, but may be correct given the engine work. Most guys are in the 31-34 range on the intermediate. If everything seems fine below 3k rpms, just keep playing with the main jet. You will know when you hit the right one.

No I have the big radius 2-2 with the Big City Thunder baffles, sounds like its open. I did put a 42 in just because its new and the 40 is all chewed up which shouldn't make much of a difference. Now I am waiting on the ejector nozzle o ring to come in tomorrow. There was not one on it, so whoever put the 96 in more than likely lost that and never replaced it. I talked to S&S and an engine builder on Big Dog Motorcycle riders they both said stay with the 36 and try a 78 main. The rpms are great up to 3k then it gets flat. Going to put it all together tomorrow night.

 

[King Lear]

All done, runs like a champ, loves to be at around 3000 rpms, 78 main jet, 36 intermediate, 42 air bleed, ejector nozzle o ring put on, new bowl gasket. Runs perfect now! I still can't believe it had a 96 main jet in it.