superman_006

I bought my bike out of NC (near a beach) about 5 or 6 years ago.... when I brought it back, I drove in around for the summer then took it in to have it rejeted for my area (Charleston, WV). It would occationally backfire into the airbox it had a little hesitation comming off idle and would pop out of the exhaust everytime I backed the throttle off fast. So the dealership rejetted the cabs and said they cant fix the hesiation or the popping out the exhaust (two brothers) and said the exhaust does that. About 2 years later I got on here and a few guys talked me though disabling some air system which almost 100% fixed the popping. However I never have gotten rid of the hesitation and it has slowly gotten worse. At the end of the last season... it got pretty bad. Ive been starting it at least once a month during the winter but it didnt seem to change.

I just ordered some NGK plugs

Under 2k rpms one of the cylenders is almost not running at all... but it then pops once and then its runs good untill im back under 2K.

(before the miss)
if I just barely open the throttle its always seems to miss or surge (it also pops out the exhasust) untill i open throttle more or go back to idle.

residentg

clean clogged pilot jet
adjust TPS

steve29

Have you adjusted the tps? They come high from the factory. Spec is 490-500 ohms. I had the same problems with my bike after rejetting until I did the tps today. Very easy to do and it can only help, even if it doesn't entirely fix the problem. Look in the knowledge base section for the how to.

steve29

Carb sync wouldn't hurt either

superman_006

to clean out the pilot jet..... do i need to remove and take the carbs apart?

is tps = throttle position sensor?

to do a sync do i have to have mecury sticks?

residentg

1. Yes, to do this properly the carbs need to be removed. You could try seafoam in the gas first, it may work. If you are not comfortable doing this, bring it to a dealer (and be prepared to pay out your butt)

2. Yes, look in KB, not a hard thing to do. It will help the starting, but only if #1 above is addressed

3. Not specifically, but you will need a syncing device, you can make one, or buy one. The cool way to sync carbs is with a TwinMax. Look in KB for this too.

TwinMax = http://www.rlmotorcycles.com/cgi-bin...69335385.72021

steve29

If you end up having to get the carbs cleaned you could probably Save some dough by yanking the carbs yourself and taking them to the shop. Then, with the info on the forum, fashion the carb sync tool mentioned earlier.

superman_006

Cool... the carb sync tools are much cooler than a few years ago

Type T

I am about to sync my carbs and all I found about this in the service manual is that the main carb is the front one and the difference should be 20 mm Hg (0,8 in). What does this mean? Rear carb 20 mm Hg less or more than the front one? This is my first V-twin, only done this to 4 cyl engines..

superman_006

hmm.... i was accually going to "sync" mine....


well i am going to unless someone could explain to me why 50/50 wouldnt make it run the best..... I am taking my carbs off right now

nath981

depends on how much money you have and how much you like to work on your own ****. I would set the TPS first,i.e., eliminate the obvious first. then probably have to adjust the idling up. Then make a sync tool for a couple dollars. Order the fitting for the front carb(4dollars), a little vacuum line and a couple of T fittings and you'll be able to sync your carbs with the tank on. Easy once you do it, and inexpensive, and satisfying.

Do this and see the diff and you likely will not have to get into the carbs. with your TB exhausts, you may need to shim the needles and adjust air mixture for best performance.

Stevebis1

Difference should be WITHIN 20mm.

residentg

Nath - that was post number 1234 for you. I notice stuff like that.

superman_006

ok....that took about 30-45 mins to get the carbs off. Whats next? where is the pilot jet?

And when i get it all bsck together where do i hook in the sync gauges? ive always hooked them to the intake boots on other bikes

Type T

WITHIN explains everything! THANKS!

superman_006

I dont know what each jet is called... but I left the main one in and pulled the other one out....the 1st one looks pretty clean as well as the inside of the carb... However the jet in my hand was stopped up but i unclogged to with a piece of wire.
I also noticed something the front carb has a 175 and the rear has a 180 main jet in it ...... is this normal?

nath981

hahaha. you probably notice alot more than just stuff like that, or maybe you're simply OCDAR.........naaaahhh. More likely you're very perceptive,huh.

nath981

it is normal. If you don't have a shop manual, you can download one off this forum. You need to order a fitting that goes into the bottom of the front carb(remove allen bolt). And set up the quick sync that allows you to merely lift your tank, hook your sync tool up, and start you engine. We can explain all this in detail but it has already been done if you search a little.

You may as well shim needles and adjust the air mixture to 2.25 turns out, set the TPS, remove the PAIR, etc.

superman_006

Yeah... i was reading the "rejetting" section in the knowledge.... It says that that the rear one is larger to make the rear cylender run richer = cooler. I also read where someone was syncing by ideling at 2k and killing each plug and figureing out how far the rpm drop is
but thats not going to sync the carbs

Whats the order I should do the TPS/ sync/idle? Because I am assuming I adjust the throttle plates to set the idle and I'll adjust the one to snyc. so each will change the TPS reading. Not to mention ill have to readjust the idle after the TPS and the sync anyhow.

8541Hawk

Well two things to add here. First, cleaning the pilot jet with a piece of wire is not really a good idea. It is very easy to oversize the hole in the brass jet while you are trying to clean it. The best bet is to just spend the $5 and buy a new one if you can't get it clean with just cleaner and compressed air.

Second, stock jetting is 175 front\178 rear but you are close enough
Then again they might have changed that in later years.

superman_006

I used the wire out of a bread tie.... it slides though the same jet from the other carb

mine is a 1998....Is 175/178 stock jetting no matter what your elevation is? I also have aftermarket exhaust and airfilter. So should I try rejetting?

nath981

as far as syncing by killing the plug, I don't know. Concerning the order, I would shim the needles, set air mixture, PAIR removal and turn plates and cap, set TPS, set up your quick sync vac lines, sync carbs,& make sure to drink a beer between each step.

8541Hawk

Well it's one of those things that might work or might cause damage. If it runs fine, then no worries. I just replace them myself so I don't have to worry about it.

The high altitude (above 6,500 ft) jetting was 172 front\175 rear otherwise it should be 175\178 stock in '98

8541Hawk

Well if you are asking me...... put the stock airfilter back in, shim the stock needles .040" and put a #48 pilot jet in and call it good.

nath981

You may be right in suggesting the stock air filter, but that doesn't coincide with my experience. I cut the flap and cut the filter out leaving only the screen. Then cut a piece of foam, put filter grease around the perimeter, and sprayed with filter oil, and installed, and it works great.

residentg

+1 ^ Soak jets in Seafom for a few hours - that will get them real clean, then use carb cleaner, then air - no wire. Note, the front and rear needles are different, do not mix them up.

The brass fitting

I urge you to adjust the TPS whie you are in there. Look in KB for sticky.

JB

superman_006

The syncing by killling a plug couldnt work... even if the theory worked youd be adjusting them with the thottle at 7 or 8 deg more than idle.. so the ofices that let it idle wouldnt even be in use

Clean carb, including needles soaked in seafoam (Check)

Beer (Check)

PAIR removal (Check) Last year

Beer (Check)

TPS at 500 omhs... in prgress (Check)

Beer (Check)

Turn Plates and cap (maybe too many beers)

Sync..... waiting on syncro to get here





Why would I switch back to the stock air filter over my K&N?

8541Hawk

Because they tend to make big holes in the power band. They are great for top end but everywhere else mine was a POS but YMMV.

nath981

superman_006

Well I tried the TPS... but mine was sitting around 970 and I couldnt get it under 730... so i am going to do the sync first since the TPS on the rear carb... then adjust the TPS even if I have to bend the tab.

I did start it..... Yay.... idleing on both cylenders


Anyone ever got the radiator cap off and added anti-freeze without removing the front fairing? I undid a line to get the choke handle out of the whole.... It looks like I can get to it but havent tried yet