ive recently had my 79 ironhead rebuilt,30 over weisco pistons,andrews Y cams new rowe valve guides,jims +.005 tappets,new manley valves and a twin tech ignition ect.ect.they put a used S&S super E carb on it. the guy at the shop i had it built at said it ran real strong so i go get the bike.when i get it home i notice that the new pipes arent even blued from them running it??? so i tried to fire it up a couple times,it started and ran really rough popping and spitting for about 5 minutes so i shut it down and noticed wow the new pipes are blued now??? any way it ended up haveing bad gas i guess so i drained tank drained fuel bowl.wouldnt start tried a **** load more times finaly got it running and all it does is spit gas out the carb and make a loud popping i tried adjusting the shorty back to factory settings adjusting a quarter at a time and it seems to pop louder either way i do it and i didnt dare to keep going with it.is it just a shitty carb,did the guy ever even start it at the shop?/ who knows my question is the loud popping could a carburetor rebuild fix the gas spewing out the carb and the popping do i need a new one are the intakes right /the carb came off a 79 harley but i wonder if it was a shovelhead?would the intake be diferant than a 1000 from a 1340? any help would be great as the guy who built it went out af buisness and wont return my messages

 

Are you capable of doing a complete tune-up on the bike?

If so that's what I would do, recheck everything, valve adjustment, carb initial settings, timing adjustment, compression check, plugs and wires, EI wiring, the whole works. Not necessarily in that order, but you get the idea.

If everything is in order after all that and still have trouble, then I would go through the carb.

 

not realy able to do that yet but i will figure it out,thats a good.nice bike i might add

 

On the XLforum, there are technical stickys on how to do all of this stuff, if you want to do it yourself.

 

Here's some notes, in the order you should do stuff.

You must get the factory service manual and the factory parts catalog. These are your first two essential tools ...
FSM: 99484-85
FPC: 99451-85A

Ironhead Push Rod Adjustment

Do this procedure with the engine stone cold. I usually do it first thing in the morning.

1. Remove the spark plugs. Remove A/C to make room to work.

2. Using a flat blade screwdriver pry the spring keeper off of each push rod; the bottom of the keeper pops out first, then the top. Alternately, use a 3/4" open end wrench to push down on the top of the spring retainer, then pry out the spring keeper with the screwdriver.

3. The lower push rod covers may be stuck tight against the bottom o-rings, but they can be loosened by pinching between thumb and finger [or carefully using a shop rag and a pliers] and twisting or rotating. Lift these up and secure each with a tall-S-shaped piece of 12 or 14 gauge household wire [not cable] [or a long piece of Plumbers solder such as 95/5 hooked over the rocker cover and under the push rod cover.

4. Jack up back end of the bike so that rear wheel is off the ground, shift to 2nd gear, rotate wheel until it clicks, repeat until you get to 4th gear. Now by rotating the rear wheel you are rotating the engine. Almost impossible with the plugs in; very difficult in lower gears.

5. To adjust a particular push rod, its valve must be fully closed [the valve spring is relaxed]. Valve position for a particular cylinder is determined by observing the corresponding push rod of the other cylinder. For example, when the rear cylinder intake valve tappet is raised [valve fully open, spring compressed], the front cylinder intake valve is fully closed, and the front intake push rod can be adjusted.

6. Check [and adjust if necessary] the push rods:

[a] use the rear wheel rotate the engine so that the rear cylinder exhaust push rod tappet is fully raised. The front cylinder push rod is adjusted correctly if it has no vertical or horizontal play, and you can just rotate the push rod between thumb and forefinger with no trace of binding or dragging.

[b] to adjust if needed: hold the adjusting screw in place with a wrench; with another wrench loosen the split locknut. Then turn the adjusting screw using fingers only until the pushrod's ball end is seated in the tappet with a "slight amount of play". Then tighten further as follows:

Option 1: Adjust on the tighter end of the range: There should be no vertical or horizontal play, and you should be just able to rotate the push rod between thumb and forefinger with no trace of binding or dragging.

Option 2: Adjust on the looser end of the range: Set the adjusting screw to finger tight so that you cannot turn the push rod between forefinger and thumb. Undo it a tiny bit so that it is just barely loose. Then loosen it 1 "side" for an exhaust or 1/2 "side" for an intake. "Side" refers to one side of the 6-sided adjusting nut.

EDIT: Experience here is that Option 2 is the better and most likely the correct choice.

[c] hold the adjusting screw in place with the one wrench; with the other wrench tighten the locknut.

[d] recheck the adjustment; it is common for the adjustment to go out as you do step [c], in which case [b] and [c] must be redone.

[e] repeat for the other push rods.

7. Use a flat blade screwdriver to push the upper push rod covers up, and seat them into the upper o-ring or cork washer.

8. Install the spring keepers, top end first, by prying them in under the bottom with a flat blade screwdriver.

Cleaning a Carb

NOTE: This is for a Keihin butterfly carb, but the principles are the same.

1. Removing it from the bike should be straight forward. First thing when it is out is to check the pilot screw setting. Turn it all the way in until gently seated counting the number of 1/4 turns; then write this number down; then reset it.

2. I put mine in a vice to remove the screws, and for much of the following work. Wrap in a shop towel; close the vice gently taking extra care with the choke and throttle linkages. The vice is a needed extra pair of hands.

EDIT: A better choice than a plain vice ...


3. You must be very careful handling the float so as to not change the level. You must have the official specs for setting the level as in the FM, and check it, every time you dismantle the carb, as the last thing before putting it back together.

4. The jets are made of brass, a soft metal that is easily damaged. Use an exact correct size screwdriver. I ground a medium flat blade screwdriver down to exact size on my bench grinder to access the slow jet.

5. The general appearance of the inside of the carb is not necessarily a good indication of its condition. It can look spotless and have clogged jets, or look cruddy and have clear jets.

6. Clean each individual part. Do not allow any solvents to contact any rubber parts [tip of needle, o-ring seal for bowl]

7. Make a list of all of the jets and passages for your carb using the carb manual or the FM for the bike. Then ensure that you can blow either compressed air or carb cleaner thru each one.

8. Remove the pilot screw and clean the parts and the passage. The passage contains in this sequence: pilot screw, spring, washer, o-ring. These are very small parts, especially the washer and o-ring. Usually the spring will easily fall out. One time i thought the spring was not in there because it would not fall out; i obtained a new spring and could not get it in! The technique for removing the washer and o-ring is to use a pipe cleaner: stick it in the hole, twist it around, remove it - you should see the washer and o-ring on the end of the pipe cleaner.

EDIT: the washer and o-ring are part of the pilot screw assembly for 1979 on. They are not in the 1978 and earlier Keihin carbs.

Remember that the purpose of the washer is to protect the o-ring from the spring and you will always get them back in in the correct sequence.

9. Dismantle the accelerator pump assembly noting carefully the sequence and orientation of the parts. Clean and inspect the parts. Replace the diaphragm if it is cracked.

10. Check the float level then carefully put it back together. I personally find it very confusing trying to decide which way to bend the tang if it is not correct. If the fuel level is low is the float high or low? Do i need to bend the tang up or down? On the bench the carb is usually upside down, adding to the confusion. Sort all this out before making an adjustment.

Best to replace the original Phillips screws for the bowl with stainless steel socket head screws.

Setting The Pilot Screw on Your IronHead

NOTE: This is for a Keihin butterfly carb, but the principles are the same.

If the carb is old and dirty the pilot screw passage may be gummed up such that you will not be able to "gently seat" the pilot screw reliably. If this is the case remove the carb from the bike and clean it up. Some guys try to do carb work with the carb in the bike. IMO this is a very bad idea.

In the pilot screw passage there should be, in this sequence: screw, spring, washer, o-ring. Occasionally POs have installed these parts in the wrong sequence; remember that the purpose of the washer is to protect the o-ring from being damaged by the spring]. The screw usually comes out easily. The other parts may require some work. The best technique is to stick a pipe cleaner in the hole, twist it around, and, like magic, out come the other parts on the end of the pipe cleaner.

EDIT: Some carbs, noteably 1966 to 1978 Sportster carbs, do not have the o-ring and washer in the pilot screw passage.

1. You need to have easy access to the pilot screw, easy enough to reliably judge "screw it in until gently seated". Loosen the front fuel tank mount bolt; remove the rear fuel tank mount bolt; prop the rear of the fuel tank up on a piece of 2X4; on some bikes this will not be necessary.

2. With the engine cold [so you do not burn your fingers] turn the pilot screw in clockwise until it is gently seated. Count the number of 1/4 turns as you do it; write the number down. Back it out to the original setting. You may need to return reliably to this setting after experimenting.

The "normal" starting point for this process is 1,1/4 [according to the 79 - 85 FM] or 1,1/2 [according to usual practice] turns out.

EDIT: An old HotXL magazine article recommends for Keihin butterfly carbs between 1/4 and 1,1/4 turns out. My experience is that this works best. If you are more than 1,1/4 turns out your pilot jet is too small.

3. The engine must be at full warm up. It will have very hot parts; to avoid burned fingers have a well lighted, comfy place to work.

4. Set the engine idling at about 1000 RPM. You want it to be idling at the slowest speed that is consistent with a smooth idle so that you can hear or feel slight changes.

5. Turn the pilot screw in clockwise until the engine idle becomes worse; tending to stall. Count the number of 1/4 turns as you do this. Then turn the pilot screw out counter clockwise until the engine idle gets good, then becomes worse, tending to stall. Count the number of 1/4 turns as you do this.

6. The best setting for your bike will be somewhere between these two settings. The FM says to use the leanest setting [most screwed in] consistent with a good idle quality. Some guys say to go between the two settings.

It should be between 1/2 and 1,1/2 turns out from gently seated. If it is not within this range you should change the slow jet.

EDIT: I follow the advice from the old HotXL mag article - set it between 1/2 and 1,1/4 turns out.

7. You may have to adjust the idle speed.

8. Make sure that the spark plugs are clean, then ride the bike. I usually go for a half hour or so ride outside the city, then ride home with the last 10 minutes at city riding speeds [so that it is on the "idle port", not the "idle transfer ports", the "mid range port", or the "main jet" [see carb diagrams in FM]]. Hopefully the plugs will come out a nice medium gray or tan color. If they are too dark you can screw it in another 1/4 turn; too light screw it out 1/4 turn, and try the ride again.

9. If they are really light or really dark the problem is not with the pilot screw setting. For example, too light might mean an intake or exhaust leak, and too dark might mean the pilot jet is too large [among other possibilities].

10. My experience with this process is that after making a change i have to clean the plugs and go for a good ride [say, an hour or so] before i can trust that the new results are reliable.

Intake And Exhaust Leaks Tests

You cannot get a good tuneup if there are intake leaks or exhaust leaks.

1. Check for Intake Leaks

With the engine idling spray propane gas or WD-40 around the carb/intake/cylinder head joints. Propane is best because it leaves no mess, and is most easily sucked in thru leaks. WD-40 is said to work well because it has very fine spray droplets. Be careful to not allow any of either to get sucked in thru the A/C as this will invalidate the results.

Any change in engine RPM is a leak which must be fixed.

EDIT: Experience is that this procedure will identify larger intake leaks, but it may miss very small leaks that also must be fixed. And that propane is definetly the better choice.

EDIT: You have to do a lot of spraying to detect a small leak. Propane will be really clean. Anything else like WD-40, carb cleaner, etc will make a huge mess.

2. Check for Exhaust Leaks

Pour about 1/2 ounce of oil into each cylinder thru the spark plug holes. Run the engine at idle. You will get lots of smoke for about 5 minutes.

All smoke should come from the ends of the exhaust pipes/mufflers. Any other is a leak which must be fixed.

Setting The Ignition Timing on Your IronHead

1. Checking vs Setting the Ignition Timing

You can check the timing without changing anything. Changing the timing can be done by one person but is easier with two. The ignition module or points is on the right side of the bike, the timing hole is on the left side. Easier with one person on each side than to go back and forth. Standard advance for the 1980 XL is 40`. I have mine set at about 35`. At 38` i get pinging.

2. Equipment That You Need

You need an induction timing light which you can buy at any auto supply store. Best to get the "dial back" type. These allow you to set a number [like 35`] into the timing light and then adjust the ignition module/points backplate until you are there.

If you have very well insulated spark plug wires the timing light may not sense the signal thru the wire. If this is the case then open the gap on the spark plug to 050 or more. Reset it to your normal gap [030 for points or 040 for electronic] when done with this procedure.

It also helps to have a throttle lock as the timing should be checked/set with the engine at 2500 to 3000 RPM.

You will need a piece of rubber oil line hose about 1 inch long. Press one end up against the side of a stone grinding wheel [or whatever] to make sure it is perfectly flat.

3. Front Cylinder: TDC Mark vs Advance Timing Mark

The TDC [Top Dead Center] mark is used with a dial back timing light to check the timing, or to set the timing at a specific degree, such as 37`. The advance timing mark is used to set the timing to the factory setting, such as 40`. Best is to use a dial back timing light to check or set timing.

4. To Identify Your Front Cylinder TDC Timing Mark

Remove spark plugs. Rear wheel off the ground, shift to 2nd gear, rotate wheel until it clicks, repeat until you get to top gear. Now by rotating the rear wheel you are rotating the engine. Almost impossible with the plugs in; very difficult in lower gears.

You want the front cyl to be at TDC. You can see in thru the spark plug hole, especially with a flash light; you can try inserting something soft like a pencil and watch it rise and fall as you rotate the engine with the back wheel but be careful it does not break or get stuck! You will have to hang on to the pencil with left hand while rotating the rear wheel with the right. Helps to have a good wingspan, or an extra person.

With the piston at precisely TDC look in thru the timing hole. You should see a drilled dot or a line. That is your front cylinder TDC mark. Once you know for certain what the TDC mark looks like you can check the timing.

5. Procedure, Checking The Timing

Begin with the engine at operating temperature. Remove the timing plug from the left side of the engine. Insert the 1" hose smooth end first, right tight up against the flywheel. I use a needle nose plier and twist it in there as firmly as i can. If it is not smooth and tight against the flywheel oil will spray out while you are working.

Start the engine, have it at about 2500 to 3000 RPM [it will be extra noisy with the timing plug out], set the timing light at 40`, aim it into the timing hole thru the hose. Click it down one degree at a time while you look for the timing mark. If you don't find it you may have to work up from 40`.

If it is in the 35` to 40` range and there is no pinging then you may wish to leave it as is. With pinging on acceleration you may want to retard it by about 1/16 of an inch or less [see Math below].

6. Procedure, Setting the Timing

Remove the points cover from the right side. You will be rotating the back plate so first mark it so you can get back to the current position if needed. Make a scratch mark or use a permanent magic marker, or better still a small bright red or whatever color paint mark.

To change the timing loosen the two standoffs holding the points/ignition module and rotate the backplate. Clockwise advances [larger degree number] counter-clockwise retards [smaller degree number].

7. Some Math, How Much to Rotate

The backplate has a 3" diameter = 1.5" radius.
The circumference = 2 * pi * radius = 2 * 3.14 * 1.5 inches = 9.42 inches
The circumference = 9.42 * 16 ~= 151 sixteenths of an inch.

One rotation of the backplate corresponds to two rotations of the engine, so it is like a circle that has 2 * 360 = 720 degrees. 720 / 151 ~= 5

Therefore a rotation of the backplate by about 1/16 of an inch results in a timing change of almost 5 degrees!

 

If that's the type of work he did then I guess his end was justified.

 

i think you should do what is stated above.look over everything and use iron micks guide etc-----but i think before you get started i would check your fire.not sure if you have electronic or points but if it were me i would check that first.
sorry you met a mechanic like that....unfortunetly alot of people out there are crooks.youre better off working on it yourself if you are in any way mech. inclined.you will have all the help you need in here.