So your saying to change out the jets, throw them away and replace with new ones of the same size??? because I had my aftermarket needles, and that could have been a problem? if so, I did that, I installed the stock ones again, and it really seems to run a whole lot better. I read that somewhere on this site, so I decided to try that. I had 2 sizes bigger than stock, I have scorpion exhaust and a K&N air filter, the shop bumped it up that far, but I have been told not to do that, so I did the ones zize up and it seems to have fixed it.

Thanks alot for the input, anything is worth everything right now. Its been good for 2 days now and running better now than ever, but still has a little hesitation, but hardly noticable.
Eric

The needles on the superhawk carbs do not make contact with the main jets as seen on most other carbs. They are at near 90° or perpendicular to the main jets. If your aftermarket needles are made from anything other than brass they will wear a an oval shape into the brass fitting they pass through in the venturi. This has been documented by other people in this thread, and by myself. I've ruin one set of carbs off of e-bay, and now I'm looking for a second set to replace this worn part.

Running Badly
 

Sorry for the poor comments, in my fogged brain condition I didn't realize two things.. The needle jet's do not pass through the main jets..you are right, but that is new to me for a bike carb..Second I did not realize there were two guys with a similar sounding problem.. I had two friends with 1500 Suzy Intruders...both titatium needles jets..both bikes hammered out their main jets overtimes..creating a similar sound issue.. It looks like titatium needles will creat issues over time and use... Are the tubes that gave problems replacable???

Great forum..
Always learning something
Thanks for the discussion
Dave:-D

Well, I've had my Ti needles installed for about 30000 miles and do not have any problems at all. YMMV, I guess.

Running Badly
 

Hey Greg;
YMMV?? Sorry, what does that mean.. Yes my motor vibrates?? Kidding. The Intruders I mentioned do vibrate lot's more than the 90 degree engines in the VTR. But I'm guessing with enough time and perhaps more time revved high.. Do you drive like an old woman Greg..:mrgreen: Kidding again...I expect you run the bike pretty hard...But perhaps there is a point where the hole the needle works in does get knocked out of spec.. My question is.. is that part a replacable part??

Take Care
Dave::-D

Your Mileage May Vary - Figure of speech in this forum that says some folks may have different results than others.

It's my hypothesis that the harder the bike is run, the less wear will occur in the carbs. This applies to the VTR or any carbureted, large displacement V-twin. My reasoning is as follows. At low rpm just above idle, the large pulses in vacuum make the slides and needles pulsate up and down. You may have heard this on your own bike. It sounds a bit like the motor is pinging. That's the slides hitting the stops and rising again in concert with each firing of the pistons. This does not occur as much at higher rpm and at higher throttle openings. Each time the needle rises and falls while rubbing against the main jet or the needle jet holder it creates wear. So to say that worn out carbs mean the bike was ridden hard is actually completely off. It means the bike was babied.

Here's a pic of the needle jet holder.

Behaving Badly
 

Hey Greg;

I get the phrase...You have an amazing mechanical knowledge..I'm not kidding. Are you telling me that CV carbs actually cycle open-closed with each piston...or on the four cycle perhaps..do they move that much.. it's a wonder they don't self destruct more.. I really never considered that before.. As the one guy put in 63,000 miles..man that is alot of up and down.. So from your rather dead-pan comment I gather that wide open is the way to go.."But officer I was just trying to make my carbs last.." Ask my question again.. (thanks for the pic).. is that piece a replacable????

Take Care
Dave.............it's heading for the minus 20s tonight...yuk

No, four strokes don't have the same phenomenon. Their power pulses aren't as big as the V-twin, so the vacuum pulses aren't as large. Remember, the slides are controlled by vacuum.

Yes, they are a replaceable part: 16166-MBB-640 for the front and 16165-MBB-640 for the rear.

PS Flattery will get you nowhere! ;)

No More Flattery
 

Hey Greg;
Again..good info. I meant 4 cycle not 4 cylinder...Vacum would pull carb slide up on intake..then it would be down through compression/power and exhaust and open again on next intake...Like I said that is a lot of movement for an non-lubricated part... I used to work in a custom metal protecting plant. My part was industrial chroming, and nickel plating. One of our specialities was a coating we called ni-flor. Big part of the shop was teflon coating. Ni-flor was a mixture of nickel and teflon which was applied by heat and eletricity. Teflon by it self is through heat.. nickel is a chemical reaction in a hot bath but no electrical charge. It was a tough and very slippery coating..Ideal for something like that..but could only be bonded to metals. Sounds like high mileage Hawks should take a peak at those pieces if they find there mixture getting sour over time..

Take Care
Dave

Very interesting piece of info.
Here's some more background. My bike has 67,000 miles on it now.
I'll say I started to notice the problem around 35k-ish, and all it was at that point was a little rough at low rpm. It has gotten progressively worse so that now it stumbles, burbles, gragbles and what other -bles you can think of. It runs so rich it will foul the spark plugs in one day, which just makes the sputtering problem worse. I bought the bike with 10k on the clock, so I know the history of 57k, and I can say confidently that 30+k of that has been with the urban landscape of the San Francisco Bay Area. We describe our bikes most oftenly in miles ridden. Have you ever thought about the number hours of operation per 100 miles ridden? Let's say hypothetically you average 40mph for every 100 miles you ride. That's 2.5 hours for every 100 miles on you odomoter. So if you've got 25k That's 625 hours of operation. Now I can guarentee that my average is no where near 40mph. I'm lucky, and I can lane split though traffic, and still with stops signs, lights, bad traffic, blah blah blah, I doubt I average 25mph per 100 miles ridden over the life of the bike. So that makes my bike 2680 hours of operation. YMMV.
The comment about the throttle not being open allowing the power pulses to knock the needle around has some weight. I think my bike is a unique case in that it is much older than the milage indicates. It's the same reason my sprag clutch blew itself apart, and nobody else has had anything like it.

Too bad the Needle Jet Holder has nothing to do with the needle. I bought two of those needle jet holders thinking the same thing. I have them unopened in the Honda bags if anyone wants them.

Please explain. Maybe a pic or something, specifically what the inside of one looks like. So you're also saying that the fuel is metered by the small brass insert in the carb throat, or am I thinking of different carbs?

Sorry its been so long since Ive looked on here, but I wanted to say that since I did all thet week long hair pulling work on my bike, its been running perfect, well as perfect as I can ask for. Im glad I found this fourm. It really helped me out. Thanks guys.
Eric

Soooo, what was the culprit; did you ever find a fix for your problem? Having a similar problem; bike runs rough in the 3-4k range. This was not gradual.
I have cleaned the carbs (jets and needles), replaced plugs (iridium), cleaned and recharged the K&N filter, nada. I am going to try unplugging the TPS today. Bummer

I forgot to update this.
OK
The culprit is definitely the titanium needle.
I bought a new set of carbs from ebay, and swapped everything over, and the bike runs great.
Unfortunately I had to use the Factory Pro titanium needles again.
I tried using the stock ones, but the bike did not run correctly.
The trick would be to find an after market needle that is made out of aluminum.
What was the culprit?
The brass fitting that the needle passed through in the venturi.
If you have an after market jet kit that uses a titanium needle it will over time wear the brass fitting into an oval.
That allows to much fuel to pass through at low RPM's.
I need to find someplace to cut my carbs in half so that I can take a picture.

Thanks for the update, glad you got your shawk running well again. I'm hoping this same thing hasn't happened to my bike. I have a factory jet kit installed, but the needles appear to be stainless. What color are your Ti needles, I'm thinking Ti should be light gold. My needles are silver. My bike is running terrible between 2500 and 4000 rpm. BTW, jet kit has been on the bike for years, and was spot on; ran like a top. This occurred suddenly, wasn't gradual.

The color looks like a polished steel, or silver. The oem needles are aluminum and look more of a gray color.

Mick-e,
The part you are referring to is called the needle jet holder/ emulsion tube, that is a replaceable part; available from Honda, Factory, and Ron Ayers.
The Factory web site mentions as these become oval or oblong, fuel metering problems can occur. Did you try replacing these before changing out your carbs?
I am going to order a set, I hope this fixes my problem. Has anyone else done this?

Brother you need to reed through this whole thread.
It is not a replaceable part unless you want to replace the entire housing at $700. It's pressed in. Unlike other carbs the needle does not make contact with the emulsion tube or main jet it passes over it at a near 90° angle.
I have a brand new set of emulsion tubes that I've never opened. I sell you mine at half what the dealer charges. ]

Maybe I'll get gung-ho tonight, and hack saw one of the carbs in half.

http://www.factorypro.com/images/jets/vtr_emu2.jpg

http://www.factorypro.com/images/carb_shots/emuwr3.jpg

http://www.factorypro.com/images/car...s/emutube2.gif

Yeah, I have read the entire thread, and in fact, have spent hours reading every thread about carbs, tuning, and emulsion tubes. Jamie Daugherty and
Factorypro even suggest using a rear emulsion tube in the front carb to remedy persistent over richness. We must be talking about a different part. BTW, the last link as a very nice gif of the fuel metering at the needle emulsion tube. The arrow points to the emulsion tube where it has been worn to a slight oval shape, they say it doesn't take much to create a problem. Regards, and thanks for your time.

This is what was confusing me. In this diagram, no.s 25 and 26 are referred to as holder, needle jet, they are referred to as emulsion tubes elsewhere. Have been in discussion with Hawkrider about this, he is about to tear down his carbs and will post pictures of the part Mark-e and others are referring to.

http://www.ronayers.com/fiche/200_03...nent_parts.bmp

A little bit of knowledge is a dangerous thing, and yes,I am referring to myself.

Yeah it's definitely confusing.
the emulsion tube does hold the main jet, but not the needle. Notice how the needle, and slider moves perpendicular to the emulsion tube? The needle does not make contact with the tube. If you go back to that .gif that shows the slider the brass part inside the venturi is pressed in, and not listed in the parts diagram.