Harley Davidson Forums banner
41 - 60 of 95 Posts

·
Registered
‘91 Sportster 1200
Joined
·
55 Posts
Discussion Starter · #42 · (Edited)
Before any work on the primary cover side:

Land vehicle Automotive tire Motor vehicle Bumper Rim

After some work with a cheap Harbor Freight hand held soda blaster gun then a brass wire disk on an angle grinder today, to remove the decaying clear coat Harley puts on their shiny aluminum parts:

Automotive tire Automotive lighting Rim Motor vehicle Bumper


This is cleaning up better and faster than I had hoped!

I’m going to get a buffing wheel for my angle grinder. I started working with some Harbor Freight buffing wheels for a drill and Mothers aluminum Polish. I never used this kind of drill mounted buffing wheel before and unfortunately got some scratches on the aluminum from the steel arbor.
 

·
Registered
‘91 Sportster 1200
Joined
·
55 Posts
Discussion Starter · #44 · (Edited)
My Harley mechanic experience is definitely coming up short.

First attempt to start it. The retired Harley mechanic who bought my side car got it started last week on ether, so I know it has spark.

As he recommended, I put lacquer thinner in the tank, let it sit over night, took the fuel line off the carb the next day, and drained it through the open fuel line, then repeated the process. So I know fuel can pass through the tank, petcock and fuel line.

I replaced the old fuel line, reconnected it to the carb, put in a new battery, fresh non ethanol gas with SeaFoam, put the choke on, and tried to start it. (Video shows the choke off. I tried to start it several times with it both on and off.)

It turns over fine but it doesn’t fire. Maybe it’s not getting gas.


(Video is for some friends who wanted to see my “progress.” This was just to show them I got it to turn over freely, even though it didn’t fire up yet.)

First attempt to start
 

·
Registered
‘91 Sportster 1200
Joined
·
55 Posts
Discussion Starter · #46 ·
New gaskets on the carb/intake? If it has the stock vacuum petcock, did you reattach the vacuum line to the petcock, as well as make sure the vacuum lines are all properly connected?
I only removed the fuel line from the carb. I didn’t remove the petcock or do anything to it. I’ll check the vacuum lines tomorrow.

When I drained the thinner from the tank it only seemed to flow with the petcock on “reserve,” not on “on,” although I drained out at least a half gallon. Is vacuum necessary for the petcock to function in the “on” position?
 

·
weird member
1997 Softail Custom (FXSTC)
Joined
·
4,130 Posts
I only removed the fuel line from the carb. I didn’t remove the petcock or do anything to it. I’ll check the vacuum lines tomorrow.

When I drained the thinner from the tank it only seemed to flow with the petcock on “reserve,” not on “on,” although I drained out at least a half gallon. Is vacuum necessary for the petcock to function in the “on” position?
If it's the stock petcock and unmodified, the vacuum is necessary in both positions. That's if it came with a vacuum operated petcock, I don't know what fuel valve/petcock the 1991's came with.

It may not have had a vacuum operated peckock, which itself is a slight misnomer anyway. The vacuum operation opens a diaphragm in the petcock to allow fuel to flow, kind of a failsafe if you forget to switch it off.

Regardless, I would still start checking vacuum lines for leaks. Even without a vacuum petcock, there's also a vacuum line to the back of the carb that goes to a VOES switch.

Whether or not it's a vacuum operated petcock, you might want to pull the fuel valve from the tank and check the filter screen.
 

·
Registered
‘91 Sportster 1200
Joined
·
55 Posts
Discussion Starter · #48 ·
Whether or not it's a vacuum operated petcock, you might want to pull the fuel valve from the tank and check the filter screen.
Thanks. I just did a bit of internet searching and vacuum operated petcocks were added to the Sportsters in 1995.

So I have to assume mine is not.

Do I have to turn the fuel on and off every time I ride it? If the thinner didn’t drain with the petcock set in the “on” position, does that suggest a problem with the petcock?
 

·
weird member
1997 Softail Custom (FXSTC)
Joined
·
4,130 Posts
Vacuum or not, yes you have to turn it off and on after every ride, especially if it's not got the vacuum diaphragm.

If fuel wouldn't flow in the on position but would in reserve, then yes that suggests a potential problem, which is why I said to pull it ans check it.
 

·
Registered
‘91 Sportster 1200
Joined
·
55 Posts
Discussion Starter · #50 · (Edited)
Vacuum or not, yes you have to turn it off and on after every ride, especially if it's not got the vacuum diaphragm.

If fuel wouldn't flow in the on position but would in reserve, then yes that suggests a potential problem, which is why I said to pull it ans check it.
I just pulled the fuel line off the carb and worked the petcock. Gas is flowing from the tank both in the on and reserve positions.


Tapping on the bowl didn't do anything so I removed the carb. When I turned the throttle assembly on the carb it was freely spraying gas into the carb from the right front brass jet (primary? Sorry, don’t know proper terminology yet) towards the rear of the carb.

I took off the bowl. Looks pretty rough in there. The float doesn't seem to be moving either.
Motor vehicle Automotive lighting Tin Rectangle Gas

Hood Motor vehicle Automotive lighting Fluid Automotive exterior


I just filled the bowl with lacquer thinner and put it back on the bottom of the carb to sit overnight. Hopefully it will free up the float assembly.

I’ll definitely be needing a new gasket between the air filter assembly and the carb. This one is in two pieces now.
 

·
weird member
1997 Softail Custom (FXSTC)
Joined
·
4,130 Posts
That brass nozzle that is spraying when you twist the throttle, the part that stays stuck to the float bowl, is the accelerator pump nozzle. With the bowl off, flip the carb body upside-down and that's where you will see your main jet (the big one you can see directly, screwed into an emulsion tube) and pilot jet (the one down in a hole).

The float not moving means probably carb needs to be rebuilt (not as bad as it sounds). Float itself might be OK, but the "float needle", which is a rubber stopper on a metal body with a spring loaded button on it, a small piece attached to the float right in the middle of where the float attaches to the carb body to prevent gas coming into the carb when the bowl is full (according to float). If that's stuck shut, you aren't getting gas into the carb from the tank.
 

·
Registered
‘91 Sportster 1200
Joined
·
55 Posts
Discussion Starter · #53 ·
Soaking it overnight in lacquer thinner worked to free up the float.

I reassembled everything, turned on the gas and tried to start it, but now gas was pouring out of the carb.

I found a barely used new cv carb off an 883 locally for $60 so I'm going to pick that up this evening. I can rebuild this carb later.

Any idea if I need different jets to put an 883 carb on this 1200, or are they the same?
 

·
Registered
Joined
·
4,852 Posts
The gas was pouring out the carb because the float is either stuck or got bent out of position. That float tab that contacts the float seat, is really sensitive! A real HD service manual would have already paid for itself with this fuel issue...
Just sayin'.

The service manual is very specific on how and where to adjust the float. I was lucky that when i was working on my buddies 883, the bike came with the factory service manual. (that bike along with the manual has moved on to a new home) So i don't have a FSM that explains the carb set up and troubleshooting any longer.
 

·
Registered
‘91 Sportster 1200
Joined
·
55 Posts
Discussion Starter · #55 ·
The gas was pouring out the carb because the float is either stuck or got bent out of position. That float tab that contacts the float seat, is really sensitive! A real HD service manual would have already paid for itself with this fuel issue...
Just sayin'.

The service manual is very specific on how and where to adjust the float. I was lucky that when i was working on my buddies 883, the bike came with the factory service manual. (that bike along with the manual has moved on to a new home) So i don't have a FSM that explains the carb set up and troubleshooting any longer.
Thanks. I received the Clymer service manual I ordered a couple days ago but I found it to be less than ideal.

I found a factory Harley service manual for it on eBay and it just got here, so now I can start referencing it instead of being the n00b asking endless annoying questions LOL.
 

·
Registered
Joined
·
6,884 Posts
Thanks. I received the Clymer service manual I ordered a couple days ago but I found it to be less than ideal.

I found a factory Harley service manual for it on eBay and it just got here, so now I can start referencing it instead of being the n00b asking endless annoying questions LOL.
Questions are good. Now you will have a manual to reference the answers to.
 

·
weird member
1997 Softail Custom (FXSTC)
Joined
·
4,130 Posts
As an easy eyeball, tilt the carb to the right angle as per the instructions and look for the seam in the float to be perfectly parallel with the bottom of the carb body. That puts it in the correct range, though slightly toward the fuller side of the adjustment range.

Otherwise, use a dowl rod, measure and mark the two spots and hold it on the carb so you can see, easier than holding a ruler or calipers.

Just make sure you're in the correct lean angle range.
 

·
Registered
‘91 Sportster 1200
Joined
·
55 Posts
Discussion Starter · #58 ·
I put a new petcock on it this evening, and a used rebuilt carb I found locally. and it started right up this evening. It doesn’t want to idle yet, but that should be a simple idle screw adjustment.
 

·
Registered
Joined
·
5,854 Posts
You are doing well grasshopper (respectfully used). As you can tell from the number of replies (help) to your posts, your good detailed feedback encourages members to think and help. Many of us thrive on the successful outcome of a member's efforts in getting his bike running properly. You can use the Clymer manual to hold the Harley manual open to the page you are using.
 

·
weird member
1997 Softail Custom (FXSTC)
Joined
·
4,130 Posts
As to your jetting (I didn't watch the video, but I know you asked)... the 883 and 1200 both use the same 40mm CV carb, just probably different jetting. Try 44 or 45 pilot jet with a 170 main as a starting point.

There's a sticky thread in the fuel related subsection of the technical section of the forum that details CV carb tuning.

I'm a big proponent of plug reading and feel for tuning over any other method (I.E. dyno pulls). For the carb, tune the idle first, since it's a separate circuit. Tune the wide open throttle next (remember, carbs are tuned by throttle position, not RPM) since the mid-range is based on the size of the needle and the main jet and wide open throttle is just the main jet. Once you know the necessary main jet, then you can figure out what needle you need for the mid-range (again, because mid-range is based on the interplay of the main jet and the slide needle).
 
41 - 60 of 95 Posts
Top