here's a carb question for you...?

[jasonm.]

First let me say I have been thru many types of carbs. This spring while getting my '87 on the road after 2 years of working on the engine I misdiagnosed a carb issue ...which was actually the boost sensor leaking. Also, I should have known better since the carbs had been drain dry 2 years ago. BUT now I have rebuilt the carbs. Using the "Gunk" bucket for all internal jets and housings. Which infact the carbs were quite spotless from the beginning. HERE'S the ODD thing(s). (1) I can do a 1st morning start with NO CHOKE just by twisting the throttle on a 70 degree day. And it will idle at 600 and slowly warms to the standard 950 or so. Not needing the choke at all. I could never do this prior to my carb work. CAN ANYONE ELSE DO THIS??? If I want, it will start w/half choke and rev to 2500 or so. I did set the low speed jets(w/digital tach) and the bike will idle forever and not load up. I do have new slide assys that I install 8k ago.. On the highway it not as smooth at my usual cruising speed of 72mph as I remember. I have removed my Jason-MOD so I could get an honest reading of the spark plugs. I removed the spark plugs after a good long ride,to check them. Oddly there are 2 colors on each...like a zebra. Light on one side and dark brown on the other side. Carbs are sync'd at idle and 3000rpm. My mileage on my 1st 2 tanks have been 41 back roads(tank 1) and 37.5 mostly highway(tank 2), but faster than 70mph. I used to get 40mpg all the time. I will say the bike pulls w/o any hesitation no matter what the temp. guage reads. So could she be too rich above idle?

Floats are set to spec-16mm below middle mark. Checked both on(by shimming the center stand for perfect level) and off the bike.Lastly, when I did the rebuild I did not replace the o-rings(looked good under the magnifine glass) and rubber plugs. I think now:think: maybe I should have...ugh! Wish I had an EGA machine. Nearest dealer with one is 35 miles away. AND making an appointment is not easy. I don't leave my bike at the dealer.

I would really like it if you guys could please give me your input before I order $80 in parts and yank the carbs. PS, trying to get this done by end of this month. Americade is almost here...

Edited May 12, 2009 by jasonm.

[Neil86]

Jason....

Did you have mod off while setting mixture screws?

[jasonm.]

Jason....

Did you have mod off while setting mixture screws?

 

Yes, of course I disconnected the MOD prior to setting the screws.

Also, I do remember it always running rough when not fully warmed up. But that could have been simply due to my bad boost sensor. Now she goes like stink no matter how long she warms. I used to always get well over 40mpg(usually 43+) back roads and right at 40 hiway @75mph. I will ride her more and check the mileage. And JUST TO CLARIFY THE POLL question... "no choke needed at all to start or keep it running, even after starting... Just twist the throttle for a split second to start and walk away..." Please everyone, continue to give me more feedback. I need to either sleep well or order parts and disassemble. Americade is almost here.

Edited May 9, 2009 by jasonm.

[GeorgeS]

I'm not sure exactly what the problem is buried in that long paragraph ??

 

Sounds to me like it running pretty good. Milage is right in the ball park ---

 

Starts good---

 

So you are saying its running a little rough ??? is that it ?

[jasonm.]

I guess I am giving too much info. I just wanted to give enough so no duplicates of what I already did.So here are the 2 things of my concern that may be related. (1) yes, running a bit rough(vibration at grips an feet) at hiway speeds(3800-4500) and (2) seems too easy to start w/o using the choke at all and goes like hell even when cold(too rich?). If I full choke it on 1st start of the day...it won't start till I back it down to 1/2. This I do remember as somewhat normal-not needing full choke unless truly cold out. But it would still start w/full or almost full choke which was often needed on a cold day(40 degrees). Now it hardly needs any choke. But does rev up when I apply choke most of the time. BUT other times will stumble and not rev up unless I use the choke and throttle together ...like it's telling me, "It's already warmed up and I am making her too rich". Choke giving gas and throttle giving the air. I have had this beast for 20 years and I am rechecking, "what is normal". As no other bike I have ever had from this time period could be started w/o the choke and keep running w/o it for the 1st minute. Heck, once it starts no choke, which is instantly I don't touch anything. It just idles.

DID I DO something GOOD or bad during the rebuild? Maybe you all will have to take turns ridng it at Americade? And give me feedback.

I do see many replying theirs also can be started like mine. So now it's the vibration issue at the hiway speeds. But this may still be a richness problem. May not be getting the proper mixture when the slides are open. Like I said before, the spark plugs look oddly colored.

Edited May 9, 2009 by jasonm.

[jasonm.]

LATEST update...I decided to see how rich it might be running. So knowing that the bike will run, but poorly w/o the air filter in. ..... I warmed up the engine- I took the air filter out. I know it should not be able to run completely properly unless the air filter is installed. Results-It idles fine & I can turn the throttle slowly or lightly blip it...then as the revs rise and slides try to open...she then boggs. Which I know is the "norm". So if any cylinders are rich ....it's likely a minority. I do remember the right pair spark plugs darker than the left. I will check the spark plugs after many more miles. I did sync the carbs. Bottom line...wish I had an EGA machine to figure out which cylinders might be giving me a problem...If I have a problem. Then I could save myself much time.

-Continue replying with your thoughts and ideas.

[GeorgeS]

Well, possibly an Intake vaccume leak, around the Manifolds where they mount to the cylinder heads ?? ( maby ) Have you had those removed?

Sombody said he installed new O-Rings there, but still had to use sealant, to stop an intake leak.

 

You -- Might --- have a sick plug. I have gotten bad, " NEW " plugs out of the box a couple times. ??? Just a thought.

 

Have you tried a set if NGK Iridium Plugs.

 

 

My bike, cold, usually starts with about 1/2 choke.

With hot engine, no choke required.

 

Plug wires ?? did you remove the 7MM solid copper wire from Caps, and coils and inspect the center conductor where it screws into the caps and coils ??

 

I guess due to running rough as you say, I would also replace the plugs one at a time, if you hit the right one, ( If one is sick ) it should be apparent when you change the right one.

[6m459]

Miy blue bike prefers to start with no choke on but likes to have choke added once she fires. She will die unless I add in the choke, but doesn't like it till she fires.

 

It has always seemed an odd behaviour but we get on OK so long as that's how I treat her. Only downside for me is that it takes two hands to get her going.

 

My red bike seems to need the choke on about half way first, but I don't have a lot of experience with her likes and dislikes, yet.

 

Hope this is of interest.

 

Brian H.

[Freebird]

Jason,

Don't know if you've ever used one or how much it will help but I have a Colortune I can mail to you if you want to try it. If I send it now, I would ask that you please try to have it back to me by June 6th which is Maintenance Day.

 

Don

[BOO]

This may or may not be of interest.

I have had three first gen bikes and all three of them started a little different.

The 84 needed about 1/3 choke to start, the 86 needed at least half to start and

the 89 barely needed any, a 1/4 of the choke at best.

I never tried to start one without the choke. And the sweet spot running down the highway was about 65/67 MPH on the 86/89, can't remember about the 84.

Never had a Carb issue with any of the bikes and I probably put close to 200,000 miles on the three bikes.

I'm thinking you may have an air leak also from the sounds of the engine running rough but just a wild guess without hearing or seeing the bike, (And then it would probably be wilder.)

Did you try a compression test?

Good Luck,

BOO

[jasonm.]

As far as an intake leak goes. My air box is sealed up perfect with permatex ultra black. No oil drips out. Thus it's air tight. I did check the intake manifolds using wd40...which should cause a misfire. Also my issue it is likely too rich. My latest test- I let her just idle for 3 x 15 minute stretches to get the water pump gasket to set up which was my latest thing on another thread.As my latest test shows the plugs very black w/o using the choke. Yet, she idles very good. Again I use a digital tach which shows changes in 10 rpm increments as I adjust the pilot screws...which you just cannot hear but the tach does not lie. Also the pilot screws are mostly at 2-1/4 CCW. Which is I believe cannot be too rich under normal circumstances. How many can start a stone cold bike 1st thing in the morning. ANd drive away in less than 3 minutes and give her the gas hard w/o so much as a hick-up. Unless you have EFI. I am thinking that when I pulled the "jet blocks" and I did not change the damn tiny o-rings that seal against the brass needle jet assys. Now some fuel or vapor is getting in when it should not. . Dumb arsss me. Compression test not yet. But when I had the engine apart I did put oil in the cylinders...knowing it was a long job. And last time on the dyno(4 years ago) she pulled 93hp...yes she's stock.As far as the colortune. I'll get back to you.

Edited May 10, 2009 by jasonm.

[Neil86]

What about the coasting enrichment diaphragms....are they new?

[GeorgeS]

Well, how about the Level you set the floats at ??

 

The fuel level, will effect the Mixture.

 

IF fuel level set to " High " it will run Rich.

 

If fuel level set to " Low " it will run Lean.

 

If your floats, are heavy, then level might be high, causeing rich.

 

I'm just guessing here !!

[jasonm.]

Well, how about the Level you set the floats at ??

 

The fuel level, will effect the Mixture.

 

IF fuel level set to " High " it will run Rich.

 

If fuel level set to " Low " it will run Lean.

 

If your floats, are heavy, then level might be high, causeing rich.

 

I'm just guessing here !!

 

3 out of 4 carbs at the 16mm below center specification. Checked both on the bench many times and bike. To be sure on the bike. I had to shim the center stand and front wheel. ANd with the bike running. Let's just say, I am a perfectionist on these mechanical bits. The 4th carb is at 15mm...no problem. You have to be way off on the levels to cause rich or lean issues. Again floats are at spec. One thing I did not do, is get new spark plugs. Just cleaned the old ones that had about 6k on them. I have gone 20k on plugs with no wear or gap changes. I am going to check the plugs after another 100 mile hiway run and let you know. Coasting enrichers... I never messed with those. As I believe- when bad , they cause popping when you roll off the gas ....no popping here.

Edited May 17, 2009 by jasonm.

[GeorgeS]

Well I guess at this point, with everything considered, if it was me, I would Maby Try a different Plug. Hotter, or Colder, ??? Are U useing the stock NGK number plug ?

 

Maby an Iridium NGK, and get the Cross to the stock NGK plug number.

 

ie: New set of plugs, and take it out for a 500 Mile run, keep the RPM's UP, pull in the drive way, pull the plugs and have another look at them !!

 

One other item, (??? ) the Air Filter. Is it new, or has it been cleaned several times ? Possibily some air flow restriction.

You might consider useing a K + N air filter.

 

There has also been discussions about re-shimming the Needle's on the carb pistons, to improve fuel economy. If nothing else keeps it from running rich, this might be worth some consideration.

 

Another consideration, might be running Sea-Foam for several tanks of fuel, over time this might clean up the Valve Seats.

 

Also use some sea foam in the oil, and run for 1/2 hour, before changing oil. Possible there might be a stuck Ring on couple cylinders. Running a cleaning agent in the Oil over time might clear that, " IF " it was a problem.

 

That brings up another thought, have you done a Compression Check ??? This might give you a clue as to any other problem. ( possible some valves, not seating correctly, Sea-Foam, might cure this over 500 to a 1000 miles of Hard, Rideing .

 

Again, just guessing on all this. But, thats part of the game, as they say,

 

Remember, this is supposed to be FUN!!

[jasonm.]

here's the latest after my cleaning and a romp on the hiway for 100 miles. Prior to me going out I set the low speed screws #1- 2.5 ccw, #2 - 2.25 ccw, #3 - 3.5 ccw & #4- 2.25 ccw. These were all done with my tach and finding the peak setting and turning it in 1/4 turn(lean drop). 1st...plugs are not black since the latest cleaning. I think I had had the bike started too many times w/choke for too long. SO NOW The insulator tip looks almost light brown fading to orange and then rose color. All within the top half of the insulator. Then you see the white far down. There are also still some dark bits that did not burn off. Also this ride was...FAST. Which after you read further the darker areas should have disappeared. I found myself 90% of the time doing over 75. often going 80+ and did three full throttle roll on tests. Saw 115 on the speedo 2 times on a slight down hill. The good is the new steering head bearings makes the bike ride on rails. The bad is, I compared an old spark plug I removed in '97 . Which showed it was obviously running "cleaner" back then. In '97 the color was a just a hint of light brown or orange towards the very tip and fading quickly away to white. So 80% of the plug's insulator was white back then. Did 100 miles in less than 75 minutes. Got just under 35mpg. With the latest carb settings... oddly enough the faster I go...the smoother the engine is. She buzzes oddly at the grips @3500 in 5th. She get much smoother @ 4000 & above 4300 . She is liveable at all highway speeds but is quite nice @5000-6000+ in 5th...you do the math. Next test is doing back roads at speeds of 45 - 65 then read the new plugs I just installed. Also for those asking, I did change my plug wires and caps 4 years ago. Never a spark problem. And I do have a clean K&N filter in the air box. Lastly, for those who have removed the jet block. The o-rings that I did not change located around the brass needle jet. I have no idea why they are there? As looking at the old gaskets show the gasket would and did effectively seal this area. I of course replace the gaskets. But the new gaskets are of a different material.Anyone know for sure the small o-rings exact purpose? I suspect the o-ring to seal the needle jet shaft better. ANd since I did not change them...this is likely my issue. FYI- I could never prior to this ever start it cold in the morning w/o choke. And for the few who said they can start w/o choke but it idles pooly and or dies. This is where mine used to be years ago. I used to get great MPGs @37-45mpg. Now those great MPGs are gone. I bet you guys who need choke or runs poorly w/o it get nice MPGs.

Edited May 13, 2009 by jasonm.

[jasonm.]

2 things. 1st- I should have included in my poll. "can you start the bike w/o choke and ride away within 3 mins. w/o bike showing any hesitations?" I can now but never could before. Always needed a good warm up. Now after putting in new plugs and checking after 100+ miles at speeds of 45-65 in 5th and engine speeds basically 2500- 3300. The plugs look clean. BUT damn I can't get over 40mpg out of it when driving like granny on the back roads. I used to always get 40+ on the back roads w/38-40 at hiway speeds 70-75. So now I'll tear into the carbs and replace them o-rings. Oh joy...I should follow my own advice. "When in doubt swap it out"

[skydoc_17]

Hey Jason,

I too am somewhat of a "perfectionist" my self when it comes to things mechanical. George S. brought up an excellent point about the shimming of the needle seats in the sliders. I did this mod and after trying a few different shim thicknesses I hit on a good combo that has showed a noticable change in gas milage, and vibration. Here is a older thread with some pics that will give you an Idea what took place:

 

http://www.venturerider.org/forum/showthread.php?t=35110&page=2

 

The pics of the needle seat mod are on the second page of the thread near the bottom. Plus you may find some of the other mods of interest as well.

I hope this helps,

Earl

[GeorgeS]

Well, 100 miles, in 75 min. = 80 average. For those speeds. it think 35 is pretty good.

 

Do a nice conservative drive at 65 to 70, flat land, and I est. 41 to 45. Thats about average for these beasts.

 

Sounds to me like your bike is running just fine !! ( stow the tools, and go ride !!! )

 

Even if it does burn a little extra, so what?? your not paying sales tax on a new Harley !!!!

[jasonm.]

Well, 100 miles, in 75 min. = 80 average. For those speeds. it think 35 is pretty good.

 

Do a nice conservative drive at 65 to 70, flat land, and I est. 41 to 45. Thats about average for these beasts.

 

Sounds to me like your bike is running just fine !! ( stow the tools, and go ride !!! )

 

Even if it does burn a little extra, so what?? your not paying sales tax on a new Harley !!!!

 

Being a perfectionist-I hate me sometimes. Had I changed the o-rings(which looked okay) from the get go, I would assume all is normal with todays gasolines. Also, sometimes I swear I smell it running rich sometimes when come to a stop. Maybe I am dreaming? Doing an MPG test on flat roads is not possible...Out here there are no flat roads. I live in a rather hilly area. Some that make ski jumps in Utah slopes down right timid. My latest test was solo and doing all back roads 45-70mph...got 39.5mpg I may have jumped the gun by ordering parts and it's too late to stop the order. Just have to weigh the time factor of doing the carbs' " needle jet o-rings" change now vs. waiting till after Americade or not do them at all and have a pile of $$ parts sitting around.:puzzled:The other thing is I had forgotten to repeat,that my "original boost sensor was bad"-vacuum leak. I replaced the bad boost sensor just prior getting my beast back on the road this year(she was apart for 2 yrs). The bike does pull harder than ever before from all RPMs. I have owned this bike since '89. Even after 2 years being off it , I remember most of the oddities. Such as when and when not to gas it hard and when it will pull crisp and smooth. NOW-The WOW factor is everywhere. Now there is ..."it's hang on time to go". Maybe because the vacuum leak is gone. There is absolutely no delay from twist to acceleration from any engine speed above 1500 in any gear. The slightest twist makes a quick and noticeable change in speed instantly... w/ or w/o the Jason MOD... Almost EFI like. Must sound like I am worrying about something good.

And a new question: would a good boost sensor make the MPGs go up or down? I would suspect "up".

Edited May 16, 2009 by jasonm.

[GeorgeS]

I would say your burning just about right. For that kind of driveing !!

 

The ONLY time I average 41 to 42, is on long Freeway runs, under good driveing condx. ( Outside of Mt Ranges ) Its been that way since the bike was new.

 

I have made many trips, Seattle to Los Angeles on I-5 Cruzeing freeway speeds, and about 42, is tops. Maby a little better with a Tail wind.

 

All I can say at this point, is Come in from a Hard Run, Pull the Plugs and read them. If the Color is Tan, I would not go any leaner !! Gas, is Cheaper the Replaceing Burnt up Valves !!

 

Go Ride !!!! Its almost Summer time, If you want 50 MPG, you will need A Fuel Injected Bike. ( like my Busa, it gets about 52 )

 

( Driveing conserativly on flat roads ) But its NOT comfortable.

Edited May 17, 2009 by GeorgeS

[jasonm.]

The unleaded fuel today definetly delays the plugs changing color. I did put new plugs in 125 miles ago. Cannot read any color yet. I will try to get 400 miles on them by Wednesday and read them. As stated before I leaned the low speed screws a bit(1/4 turn). And now it needs a bit of choke on the 1st start of the day. I am being prudent to hardly use the choke when starting first of the day. As I know this does leave a quick carbon coat on the plugs. Also I found my old magazines from the late 80's when they tested the Ventures. The '89 they got an avg. of 47mpg and the '86 got 45mpg. Now with today's ethanol gas, I subtrack 5% from those numbers and that's what I would expect. So 42 average I would think is highly possible...but not probable. My memory has been coming back. AND I do remember last time on the Venture to Americade(~140 miles) the reserve light started just before I got to Lake George. So that's about 35mpg. Sh*t...there' likely nothing wrong with my bike. I know coming home I got higher mpg as the elevation drop helped... I live @800'.I think L.G. is about 1500' or so. From memoryI am sure that I got 43mpg out of the bike easily. And all I had to do was keep it in 5th as much as possible on the back roads and not to go over 3200rpm. Which I came close to doing on the last tank. If you have not guessed...I am a worry wart/perfectionist. ALSO- George, Have you gone to Americade?

Edited May 17, 2009 by jasonm.

[Condor]

On the gas milage... The faster you go in 5th gear the more the bike acts like a horse eatin' oats. While slabbin' it at 75mph I'm lucky to get 37-38 mpg, but take the bike on a ride in the mountain twisties, keeping it between 2nd and 3rd gears, and hardly ever going into 4th I'll get 50mpg. 5th gear and wind resistence are the enemy.....

[jasonm.]

" 5th gear and wind resistence are the enemy..... " I am surprised you say this. 5th gear should always give best fuel economy...as long as there is not a big head wind. Also, seeing the old magazines saying mpg average in the mid-forties makes me think...I only got mid forties as a high many years ago. New gas is crap. I would think more here would get better than 40mpg consistantly. Maybe all of us have had the low speed screws set for power and not the EPA settings from the factory and the mileage suffers a bit. But more than 10% difference from the tests in my mags.(Road Rider & Rider) would be odd. Also having calibrated my fuel sender I know within a quart of what's left in the tank. On my bike, going a bit over 160 miles before the fuel light comes on and stays on usually means about 40mpg .

[Condor]

" 5th gear and wind resistence are the enemy..... " I am surprised you say this. 5th gear should always give best fuel economy...as long as there is not a big head wind. Also, seeing the old magazines saying mpg average in the mid-forties makes me think...I only got mid forties as a high many years ago.

 

Don't get too cerebral about what you read in the mag's. There are quite a few of us who ride 1stGens that have expressed the same results. Conversely the only way you're going to get good gas mileage at high speed with with a strong tailwind. What I wrote is hands on experience, not something a magazine writer has come up with in a short period of time reading a press release to meet some dead line. Take your bike out and run a few tanks thru it at 75mph+ in fifth, and then go ride in some twisties for a few tanks. Don't mix the styles up. Let us know what you've experienced.