Regarding FACTORY PRO CV Protocol.. bog 2-3.5k

[cyclosomatic]

Hey gang, I'm spending the day trying to tune out a bog right after idle, under load between 2-3.5k in first gear, happens in 4k range in second.

I've followed the Factory Pro CV methodology, and this area seems to be related to fuel level. Vacuum sync is as perfect as I've ever gotten it.
How many folks here with STOCK airbox/exhaust have played with fuel level for tuning in this area.

I'm already a little stymied, because I went up one size on OEM Pilots and am 115 OEM mains. it starts easily, plugs are dark tan (happy to lean rich as I was white before..), and it takes OFF after 3.5k. I was hoping given the stock set up and clean (twice!) and rebuilt carbs that I wouldn't have this much tuning to do.

Should I continue tuning pilot air screws? Should I do what FP recommends and go after fuel level? I'm about to go do a chop only in that area of the bog to get a proper read on it. I just wanted to see how many guys have played with fuel level for tuning on stock machines.

Thanks for you thoughts

 

[Nessism]

Fuel level is not a tuning element. Set the level, using the clear tube method, to within the factory specs, and you are done with that.

Why are you changing the factory jetting? You bike should have 110 mains and 42.5 pilot. Make sure your airfilter is properly fit, and the airbox sealed.

 

[cyclosomatic]

Fuel level is not a tuning element. Set the level, using the clear tube method, to within the factory specs, and you are done with that.

Why are you changing the factory jetting? You bike should have 110 mains and 42.5 pilot. Make sure your airfilter is properly fit, and the airbox sealed.

I bought the bike with the carbs rebuilt using unknown kit, and a cracked exhaust valve. I rebuilt the top end and the carbs were cleaned and rebuilt again. The original pilots were shot, so new ones from a kit were put in as well as kit 110. Probably keyster.

I would’ve never changed stock settings if I weren’t lean across the board and practically bucking between 2-3.5k from a lean pilot circuit. I set floats to stock and checked with clear tube method. After upping the mains to 115 and pilots to 45, I have a bike that, to me, is almost tuned.

i sealed the airbox and made a cage to hold the air filter from a Park Stool bicycle stool weld cover.

You’re right, I’m confused as to why I “needed” to change the jetting, I didn’t want to or expect to!

 

[Nessism]

Red flag about the modified airbox. Making a filter cage holder sounds like a good project for a 3D printer. Assuming you can create a proper model first.

 

[cyclosomatic]

Red flag about the modified airbox. Making a filter cage holder sounds like a good project for a 3D printer. Assuming you can create a proper model first.

Yup, but apparently 650 owners have the same chances as spotting a unicorn as finding that cone/cage that holds the UNI-filter. Little did I know I could rebuild the top end of the engine, clean the carb twice and rebuild, and be at the mercy of a plastic cone

 

[tom203]

A crude cage should work adequately …do you have the rubber plugs on pilot jets?
do your jet needles look like these in link…or are yours more creative?

https://www.ebay.com/itm/3008801788...RSR0K5ISZu&var=&widget_ver=artemis&media=COPY

 

[cyclosomatic]

A crude cage should work adequately …do you have the rubber plugs on pilot jets?
do your jet needles look like these in link…or are yours more creative?

https://www.ebay.com/itm/300880178819?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=YRXifaZBQQ2&sssrc=4429486&ssuid=ARSR0K5ISZ u&var=&widget_ver=artemis&media=COPY

Thats what I was hoping! Filter is oiled too. Yes, the needles look like that, I believe they’re original, I’ve got 4 that came with that kit and were not used. I’ve attempted different shimming and am at 1/4 metal shims (4 being = to the original nylon spacer). Really pulls at 5k, and up to redline!

And yes the rubber plugs are new and snug on the pilots