Discussion in 'Engine, Fuel and Exhaust' started by toddsawake, Sep 12, 2012.
Does anyone know what size needle jet came stock on an 05 Heritage tc88?
Since there is a lot of confusion of the name of various jets, I'll post the parts diagram from "Ronnies HD". Select your part from the diagram, add it to cart, go to checkout to find the part #. If size is not listed with the part # (likely), Google the part #, and you should be able to find the size among the search results. Ronnie's Harley-Davidson's 2005 Harley Davidson Street Bike FLSTN SOFTAIL® (BN) (CARBURATED) Parts List
(don't worry if I selected the wrong softail model, jets were the same).
Thanks. I see in list that #30 is for the complete assembly and there are 2 of them. Cal only and everyone else. Do you know what is different on the California models? Did N9E come on the California models also? The reason I am asking is I just cant seem to get my carb to where I want it. Got my heads and cylinders done at Dunn Performance with bigger intake and exhaust ports. 9.7 to 1 compression, 570 S&S gear drive cams, RB racing LSR 2into1 exhaust, and a stage 2 big sucker, and crane cams ignition. I have changed the jets many times with many different combinations of low speed and main jets, changed the jet needle( raised and lowered ). A friend of mine that works at a Harley dealership drilled out the needle jet holder tube and yes it definitely runs better, But... my mixture screw I can turn all the way in to seat it and the bike doesnt die. The only time it really makes any difference at all is when its almost falling out after about 4 turns. It gets lousy mileage, it sometimes coughs when I goose it a little from idling through the carb like its running lean. When I'm on it going maybe 80-85 it will cough every now and then. Any suggestions?
With all the mods done to the bike you may find that the stock cv does just not flow enough air/fuel to keep the bike happy
If you are getting no change with adjusting the mixture screw then your slow jet is too large
personally i think that a larger carb may be the answer to your situation rather than trying to get the stock cv to work
I agree with fin_676; slow jet is too large. However, don't agree that the CV40 is not enough carb for a 95" with some compression and cams. I have found the Yost kits and a handful of jets pretty handy for dialing in a CV on a performance build. The modified emulsion tube, lighter spring and drilling the vacuum port for better throttle response make a difference. Yost will usually supply two needles if you request them and each needle has three positions. Many dis the CV perforance carb kits and some is justified but the Yost kits are, IMHO, are pretty handy.
You should be able to starve the bike with the adjustment screw. If not, the slow jet is too big, OR the idle is set high too high. Fin has a good point about not being enough flow for your application. However, you should still be able to make it idle properly and even decent at lower rpm's. Check the adjustment needle tip and make sure its not damaged. It is to be lightly seated and any more than that will damage the tip. Check the enrichener valve to make sure it is seating properly and not hanging open adding extra fuel. What size slow jet is in it?
Start with getting the slow jet/idle properly adjusted and then worry about high speed. If it were as lean as you think it is, you would be able to kill the motor with the mixture screw all the way in.
Thanks for the quick reply's. I think that I need a starting point as I have changed needle jets, pilot jets, main jets, emulsion tubes, drilled the slide, cut the spring, etc. My friends shop gives me access to too many parts, and he is always too busy so I dont like to ask him to look at my bike. Yes I too thought that maybe the CV40 is not big enough but the thing that stops me from putting a bigger carb on is the fact that I only get about 100 miles out of a tank now. I know that with a bigger carb that would probably go down even more. Even with a 46 pilot jet I can close the mixture screw all the way and the bike doesn't die. The mixture screw is not messed up, I have tried 2 different ones with the same results. But with the 46 pilot it backfires through the carb when I take off from a stop sometimes. I have a 48 in now and it doesn't do that anymore. The choke is seated all the way, and in the morning when it is cold, I need the choke on for a few minutes else it will die or not start. So where can I find this Yost kit? It sounds like a good place to start.
Checked for intake leaks? Make sure your manifold is sealed perfectly. Just because the enrichner knob is in all the way doesn't always mean the valve is seated properly. Have you checked the float height? I would go back toward getting the carb stock instead of throwing more mismatched parts at it IMO.
I totally agree with Bodeen's post. Get it right before throwing more parts at it. The CV carb. is fully capable of satisfying at least 85 hp, but you're having basic problems that need sorting. It really sounds like an air leak somewhere. Is the carb. diaphragm seated, no rips? Is the carb. fully seated on the manifold, is the vac. port plugged properly?
ADD: I just reread your last post.
won't die when air screw turned full in = getting air somewere.
backfires when starting off = lean.
no backfire with bigger pilot when starting off = compensating for extra air coming in.
Lousy fuel mileage not an reliable indicator of rich or lean until it runs properly.
I feel you are going to find something basic is the problem, and I look forward (not as much as you) to finding what it is.
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