Running a bit lean since the rebuild.

[Guest]

Not sure what is going on, though my bike seems to be running lean for some reason. Noticed the pipes were getting a bit more bluer. Nothing was changed when I rebuilt the carbs as far as jets (117 up from 112 when I install the RC pipe and K&N filter eons ago and that fixed the lean problem then). Dipped cleaned etc, new orings, float needles, floats at about 23mms spread is 22-24. and all new rubber boots, clamps on both sides and carb sync. And yes the valves were adjusted. Oh and no air leaks. I took it out on the Interstate at 75mph for about 10 miles and did a plug chop, didn't really tell me anything since the plugs are brand new. So I decided to start with the plugs, they may be running a bit hot, plugs I installed were the NGK DPR8Zs/DPR8EZ (maybe off a bit on the plug) . I yanked those out and installed a new set of D8EAs, haven't had a chance to check those yet. Motor pulls great not one hiccup.

Thoughts?

[retcol]

You need to go up on jet size to 120 and slightly enrich your mixture screws. Good luck.

[BassCliff]

Hi,

Sure, I guess that's what I'd do too. I'd experiment with slightly larger main jets AND raise the jet needle a little and do some plug chops. I don't know why things may have changed. Sometimes pipes get blue no matter what you do.


Thank you for your indulgence,

BassCliff

[Guest]

Ugh, man, just didn't want to yank the carbs off...sigh. Maybe it was the new horn...yeah gotta be it.

[Agemax]

getting the horn always results in unexpected consequences!

[Guest]

getting the horn always results in unexpected consequences!

At least I know why it blows

[Guest]

Change in plugs.

I'm thinking since my rebuild, I have improved the efficiency of the motor ie, airbox seal, new rubber boots fore and aft along with new clamps, carb rebuild, new coil connections, etc. Though in the pic are some spark plugs. Left to right. NGK DPR8Z were the current plugs I have used for a few years. Middle, NGK D8EA is the stock plug and Right is a SplitFire I used more often then not until they stopping production. As you can see the DPR8Z is a bit longer at the tip then the other two plugs. I'm thinking this is why it is running hot/lean now. Plug is too hot even though it is the same heat range as the other two.