[thykeith]

My bikes a 98. Anyone know which spark plug wires go to which plugs. The book tells me nothing other than coil 1 goes to plugs 1 and 4, coil 2 to plugs 2 and 3. But I have no idea which plugs are which. A diagram or good description would be very helpful. Thanks.

 

[PatC]

I'm pretty sure the plugs in each cylinder fire simultaneously, which is why the book does not list a firing order other than coil to cylinder.

 

[sunnybob]

My bikes a 98. Anyone know which spark plug wires go to which plugs. The book tells me nothing other than coil 1 goes to plugs 1 and 4, coil 2 to plugs 2 and 3. But I have no idea which plugs are which. A diagram or good description would be very helpful. Thanks.

If I recall, the plug lead lengths are different, giving you the clue, but as Patc says, it doesnt matter. All the plugs on the 1500 vulcans fire at the same time. The firing at the bottom of the stroke is known as a "wasted spark system"

 

[sfair]

If I recall, the plug lead lengths are different, giving you the clue, but as Patc says, it doesnt matter. All the plugs on the 1500 vulcans fire at the same time. The firing at the bottom of the stroke is known as a "wasted spark system"

Hmmm, not quite correct.

Front pair fire together and rear pair fire together at the correct time for that cylinder. All four do not fire at the same time.

As an add, the "wasted spark" occurs at top of stroke, not bottom.

 

[sunnybob]

Hmmm, not quite correct.

Front pair fire together and rear pair fire together at the correct time for that cylinder. All four do not fire at the same time.

As an add, the "wasted spark" occurs at top of stroke, not bottom.

we've dome this to death, whatever.

 

[thykeith]

Yeah I've read some old posts and I undertake the whole "wasted spark" thing, but what I still don't get is this. Does the left coil feed to the left side of the bike, and right coil to the right? Or do the wires stagger? Example: coil 1 feeds spark to left plug on front cylinder and right plug on rear cylinder. Or does it not even matter.
The root of this question is, I just had the top end rebuilt and it's running just like it did before... Worse actually. Will fire and turn over, after a while of holding starter and pumping the throttle, but will not stay running and sounds like it's firing rough and inconsistent.

 

[sfair]

we've dome this to death, whatever.

Sorry, I do not know what you mean by this.....

 

[sfair]

Coil with black and red wires go to the front cylinder, coil with black/green and red go to the black cylinder.
Actual high tension leads for each coil can go to either sparkplug for an individual cylinder, it does not matter.

What problems were you having in the beginning?

 

[thykeith]

Thanks sfair. Here's my quick history with this bike. I got it off a buddy for $500. It had been sitting for 5 years and had 90k miles on it. I cleaned it all up, everything in the carb was seized up so I went through that with a fine tooth comb. Got it running. It would idle good, but no power. Just bogged when I gave it throttle. Took it to a shop and they got carb tuned, but had no compression in front cylinder. Top end rebuild later, I stabbed the motor back in the frame, got everything buttoned up (except unsure of proper placement of spark wires). That's where I'm at now. Won't even idle for me. Pretty sure I burned up the starter relay cranking on it so much cause the starter got stuck and I had to pull the battery. Haven't diagnosed it yet however. But, the one time it did start, it idled very rough for about 4 second and died.

 

[sfair]

1. What was the actual compression readings you got front/rear?
2. What was checked/replaced/repaired in the rebuild?
3. To check starter solenoid, pull connector cable from top, then touch cable to battery. If starter wants to run, solenoid is bad.
4. Did you replace fuel filter and check fuel pump pressure and flow rate?
5. Pull the plugs and tell us what you see, picture even better.
6. Is the tank clean inside?

I do not mean to lecture, but these engines are easy starting and if it will not start right up, then repairs are in order. Excessive cranking will not help/fix anything and only puts strain on the battery, wiring, starter and its drive components.

Post back.

 

[thykeith]

I'll get some info together and get back. Thanks.

 

[thykeith]

1. What was the actual compression readings you got front/rear?
2. What was checked/replaced/repaired in the rebuild?
3. To check starter solenoid, pull connector cable from top, then touch cable to battery. If starter wants to run, solenoid is bad.
4. Did you replace fuel filter and check fuel pump pressure and flow rate?
5. Pull the plugs and tell us what you see, picture even better.
6. Is the tank clean inside?

I do not mean to lecture, but these engines are easy starting and if it will not start right up, then repairs are in order. Excessive cranking will not help/fix anything and only puts strain on the battery, wiring, starter and its drive components.

Post back.

1. All they told me was that rear was in spec and front only had about 10 lbs.
2. So far as I'm aware they did a complete top end. Pistons, rings, honed cylinders, valves replaced and adjusted, etc. The problem was that one guy started the rebuild, quit, and another guy picked up his pieces some 4 months later
3. Starter solenoid is definitely bad. Got a couple on order.
4. New fuel filNGK . Checked pump, seemed to have good flow.
5. Here's a pic of the plus. They look carbon fouled, but not the right plug. They put NGK DCPR7E in it. I was running DPR8EA. Gonna pick some up today.
6. Thank is clean-ish. Rusty but no loose rust or debris.

 

[thykeith]

Image of plugs

 

[sfair]

Those plugs look terrible. We will get to them in a bit.

A shop did the rebuild? Does the work order say what they did and why? Would like to know that.

 

[thykeith]

yes it was a shop, but kind of under the table hook up deal. I'll see what I can get.

 

[thykeith]

Another question...
What goes here?

 

[thykeith]

Here's the photo

 

[thykeith]

ok just talked to my guy at the shop, looks like a complete top end. Rings, pistons, cylinders, intake valves, exhaust valves, cam chain, cam chain adjustment, gaskets, o-rings the whole shebang. I got new spark plugs in it, the correct ones. Got a new starter relay from eBay, going to put that in today or tomorrow. I'll give it a crank, see what happens. If it won't start I'm thinking timing might be out or valve adjustment.and I still can't figure out what that little port on the front cylinder goes to, breather? Don't know if it needs to be open or plugged.

 

[madhatter4119]

Isn't that your crank breather line...I believe most put a small filter on it if they have
changed or mod the air filter and reed valve setup...If it is the crank breather line...blocking it off will cause pressure build up and force oil leaks...it needs to breath...Have you done a compression reading for both cylinders...If so...what were the numbers...Maybe they did a reading after the top end job and have it...But I would still do one to compare the numbers...if you do one...make sure you have the throttle wide open...good luck

 

[thykeith]

Yeah, I figured it was something like the crank case breather. They didn't do a compression test because I pulled the motor myself to save $$ on labor costs. Once I get it running good I'll take it over and have that done.