I set out to set my timing the other day and when I increased my idle to 2000 rpm. I used the high speed cam and adjusted the idle up from there so if things got crazy I could drop it down quickly. I began to notice that my pipes began glowing red. So I dropped it down and stopped. A fella at the local shop seemed to think it was a timing problem to cause the glow. Is it possible that timing can cause this. I don't seem to have any leaks on intake. I tried using Mapp gas all around the intake manifold and at heads with no change in engine speed so I don't feel I have a leak anywhere. Or should you not use the high speed cam to increase idle. To me, I would think if anything it would run rich.

 

if you set timing at 2000 rpm wouldn't your timing be WAY advanced?

 

What year is the bike? What ignition? What carb? Using a VOES?

I believe the high speed cam on the carb is set by the choke ****; it is supposed to be adjusted to set the idle at 1500 RPM with a warm engine, and used when warming up a cold engine. I would not use this when setting the timing.

What i do is use the throttle lock to set the idle at 2500 to 3000 RPM. At lower RPM my experience is that the timing mark does not sit steady in the hole.

A VOES should be disconnected when setting the timing using a dial back timing light to set the timing using the TDC mark.

I don't know enough about engine mechanics to know the relationship between red hot pipes and ignition timing. But i have heard that this can be the cause.

Also could be caused by exhaust leaks - but if it were either intake or exhaust leaks you would most certainly have noticed before doing this timing exercise?

You can test for exhaust leaks by pouring 1/2 ounce of any oil into each cylinder thru the spark plug holes then run it at idle. You will get lots of smoke for a few minutes. All smoke should come from the ends of the mufflers. If any comes from the pipes at the cylinder head this must be fixed!

 

[quote=AmericanNightmare73;4996396]I set out to set my timing the other day and when I increased my idle to 2000 rpm. I used the high speed cam and adjusted the idle up from there so if things got crazy I could drop it down quickly. I began to notice that my pipes began glowing red. So I dropped it down and stopped. A fella at the local shop seemed to think it was a timing problem to cause the glow. Is it possible that timing can cause this. I don't seem to have any leaks on intake. I tried using Mapp gas all around the intake manifold and at heads with no change in engine speed so I don't feel I have a leak anywhere. Or should you not use the high speed cam to increase idle. To me, I would think if anything it would run rich.[/quote

[Used the 'high speed cam' and adjusted the idle up from there???]
Man, you lost me there.

You have a 1973 XLCH, correct?
Trying to set the timing you need to do the following:

1) Adjust the points gap to .018.
2) Set the adjustment hold down screws in the center of the adjustment slots at the points backing plate.
3) You will need a timing light and a plastic plug to put into the timing hole.
Start the engine, clip the timing light pickup to the front spark plug wire. Attach the other timing leads to the + / - battery posts.
4) Run the engine at 2000 rpm. This rpm will advance the centrifugal advance to the full advanced position. This is where a Sporty is timed at.
5) Hold the timing light shining on the hole with the plug while the engine runs at a steady 2000 rpm.
6) You are looking to see a vertical slash mark in the hole. If you do not see it, move the backing plate first one way and then the other way if the slash does not appear soon.
It helps to have an extra pair of hands when doing this, so grab a buddy to help you.
With the slash in the hole (anywhere as long as it shows up, tighten down the backing plate. Your timing is set correctly at this point.

Yeah, red pipes say detonation, big time, and it could be the timing is off. Most likely it is from the description you gave of the way you set the timing. Do not run it with red glowing pipes or else you are going to melt a piston!.......... pg

 

Thanks Mick and Pinion. It is a '73 XLCH w kick only, but when I got it, it already had what looks like a Dyna electrionic ignition instead of points. To Pinion, what I meant was in line with what Mick said. I used the choke "high speed" cam on the Carb to increase my throttle (idle) speed. I wasn't sure if this was the cause of red pipes. What exactly causes the red pipes. And what may be the cause of detonation? I didn't ride at all last year. But last time I did, it ran great and would start within the first 3-5 kicks after 3 kicks with ignition off. Now I can kick for like an hour straight and it only fires like 3 times but never starts unless I roll it down the driveway.

 

Yep PG and Mick knows what they are writing, there some reasons why pipes are glowing red hot : timing is off specs, you have pointless so it is good to use strobo light to set it right.
Mixture is too lean, manifold lead or carb mixture adjustment.
Have you checked pushrod adjustments ?
Dragpipes made from thin material, they start easily glow specially when you are running engine higher rpm than idle.

 

So it ran well, then sat for a year, now will not start.

It would be a good idea to fully charge the battery, then have it load tested. It is important that it be fully charged for this - just charging it overnight is not good enough; some of these large batteries take 24 hours or more to fully charge. Best to use an automatic charger, or do a specific gravity test for a liquid filled battery.

Then check the ignition coil - there are two resistance tests in the manuals. Check for spark with the spark plug grounded on the engine. Note: with electronic ignitions never [attempt to] run the engine with a spark plug lead disconnected.

I would dismantle and clean the carb, blowing carb cleaner or compressed air thru all jets and fuel passages; and check the fuel filter, fuel line and tank for crud.

I would, as already suggested, check the pushrod adjustment. It would not have changed with the bike sitting there, but it is important with this symptom to know that it is correct.

 

Opps! Sorry about that. I was not aware you had electronic ignition. Since I am a points and condenser type of guy I cannot help you there.
You do need to uae a timing light though.
You also need to read what the timing procedure is for an electronic ignition. Obviously you will not have a centrifugal advance, so you need to find out how the advance is set with an electronic unit.

I have to say in 52 years I cannot remember actually seeing red pipes. Heard of it a few times though.
This is a real concern because if you can heat steel up to the red point, think of what your poor aluminum piston must feel like at this time?

The red pipes are caused by the timing being way off, a lean condition as Sepixlh said, and perhaps bad gas could add to the mix.
If you are running the bike with the choke on though, this is going to have a cooling effect as the air/fuel ratio is heavy on the fuel side of things. Turning the pipes red is way-y-y-y too hot though!

In any case, I believe the ignition timing is way off and that is reason for it not wanting to start easily. Find out the procedure and correct this before you run the engine again.......... pg

 

NOTE: I wrote the following for a bike with a single fire ignition. There are issues when using a timing light with a dual fire ignition, and i am not familiar with those. I think the process still works but the mark may not be as clear in the hole. Others may comment on this.

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!

 

actually, the Dyna S uses the same mechanical advance assembly as points do. When you set the timing, follow the steps given by mick or pinion, just skip the point gap step. Also, I haven't had any luck seeing the timing mark through the hole with the plastic plug in, so I put on a pair of safety glasses to keep the oil mist out of my eyes and leave the hole open. My pipes also liked to glow red after a min. or 2 of running at 2000 rpm's, so I put a fan next to the bike blowing right on the jugs to help with cooling. Remember, these bikes are made to be moving when they are revved up like that, and don't have any airflow to help cool anything when they are sitting still.