soggy on the low end

[the108penguins]

I've been playing with my carbs tuning, un-tuning and re tuning again lately and when I open up the throttle it kinda drags until about 3K after which I have to tuck my self into the seat to stay on the bike at about 6 acceleration slows down a bit again but still pretty strong. what jet or part of the carbs controls the low end power? where should I look and what should I adjust?

[planedick]

Maybe

It might be lean. To find out listen when decellerating, if it backfires that means it's lean on the low end. Raising the float height will help a lot. Make sure you balance the carbs each time you take them apart of adjust anything, even just the idle screws.

[natemoen]

This seems to be a popular problem right now, I am fighting it and there are several other threads discussing the same sort of thing! Good Luck!

[petejw]

when i was mucking around with float levels,
if the float was on the lean side it would make
acceleration really flat, what have you got your
floats set at?

what carb specs have you got at the moment,
jet sizes etc?
and any mods to the exhaust or air filter?

jst saw ur signature, if your running pods with the early model
carbs that have the vent tubes running to the airbox, itll be
near impossible to get that setup right, the vents need to be attached
to the air box to work correctly.

[TopCatGr58]

jst saw ur signature, if your running pods with the early model carbs that have the vent tubes running to the airbox, itll be
near impossible to get that setup right, the vents need to be attached
to the air box to work correctly.

Hey penguin and Pete,

The early carb vents and their tubes don't necessarily need to be connected to an airbox nipple, they just need to be connected to a real VENT, and not connected ONLY to each other. Folks with Pods usually put them from 2 carbs into a "T" fitting, and then the end of that "T" into a little filter, or long hose that can be secured up under the tank or such....just needs to be open to air flow.

Problems occur when folks connect the carbs to each other but not to air, or if present, the air box nipples or carb vent "T"s are clogged. Yes, pods pose tuning challenges, but the vent tubes just need venting, not an airbox.

T.C.

[the108penguins]

wow ok well that might help... ummm.... where are these vent tubes you are talking about

[dbeardslee]

Soft and boggy on the bottom is generally a sign of a rich condition. What do your plugs look like?

[the108penguins]

when I checked the plugs after a nhour ride they looked pretty black (i.e. rich) but I'm not sure how to check them for just the low end rpm's

[dbeardslee]

Do you have a colortune plug?

[the108penguins]

yea i color tuned them all and it's still weak off the start

[dbeardslee]

When you colortuned were you able to adjust through the entire range of color - out to yellow, in to bunson blue, and in more to white/blue? I've found colortune to be a pretty good indicator of jetting - if you can go through the entire range it's most likely correct. When I use mine I adjust out until I get full yellow, and then come back in until it's bunson blue, and then go about 1/4 turn in from there.

Along the lines of what Pete said, I've found the float height tends to have the biggest impact on the black ring around the plugs. They need to be measured correctly, from the gasket seating surface (no gasket) to the top of the floats, and you need something that hangs over the float. When I do mine I use a combination square, but a caliper (depth gauge end) works just as well. I set my measuring device 1mm proud of the mark, and adjust the floats until I can see about 1mm of light between the top of the float and the 'measurer'. You don't want your measuring device to actually touch the top of the floats - they're way too easy to push down.

Two other things you might want to check - slide needle position and the condition of your floats. Sometimes those old brass floats will leak, and that throws the whole game off, and results in an over-rich condition. It's easy enough to tell if they leak by removing them after they've been immersed in gas for a while (like out of carbs that have recently run) and shake them. If you hear liquid inside, that's a bad thing. Slide needles should be on the middle notch, and you might check and see if there are any numbers on the needles, just to make sure you have the proper ones installed.

[the108penguins]

IIRC I set my floats at 25mm the manual said between 24-26... I think.

[dbeardslee]

Spec is 25.7mm plus or minus 1mm. Sounds like you might need to raise them a mm or so (upside down orientation) - it makes a difference.

[the108penguins]

I'm still wrestling with my carbs... I raised the floats a mm so i'm at 27 now and #1 carb started leaking fuel out the throat yesterday. so it's not sealing properly. they are definitely the older style carbs and I've rebuilt them with the kits. I'm running pods and a 4-1 exhaust but I still have the stock jets in running 137.5 mains should be around 147.5 according to the jetting recommendations but I figure it still should have a pretty even power band if maybe a bit weak. the screws that cover the pilot jet don't have any washers under them and I heard mention that might cause a problem also had to remove a broken mixture screw tip from the #2 carb I tried everything I could think of (and everything a few others could too) eventually drilled it out so that passage way is now a 16th instead of a 32nd not sure how much of a difference that would make on the low end, I mean it is just one carb.

[MindWebs]

Take it from me....

i have all 2 months into trying to tweek and drill the jets.

Don't bother.

set your floats correctly, as you are doing..

and rejet the pilot to 45.0
and the main you may have to play with...

but start at 147.5!! that will get you close. dbeardslee knows his stuff.

look at his sig and you'll see that his system is opened up to.

i just ordered those parts and will have to see how it works for me.

Georgefix is the cheapest to order jetting from.
approx $2.50 per jet with shipping. (i think)

I tryed re-inventing the wheel and i hope you don't waste to much effort with the same mistake.

Good luck, we're all in this together.