Firing Order And Spark Plug Wire Order.

[Kdrich223]

I have an 83 interceptor vf750f, which I recently got into a crummy wreck! A few weeks later, I decided to try and to some work on the old stallion, unfortunately, I was still in a sling and things were not going right for me. In a fit of crippled rage, I yanked all the plugs and wires off of everything. Now I have no idea what order everything goes back to. I have scoured the web, high and low, looking for this answer, to no avail. If anyone can throw some knowledge my way, I would greatly appreciate it!

[ggathagan]

1-4-3-2
If you don't already have the service, it's in the downloads section:

http://www.vfrdiscussion.com/forum/index.php/files/file/173-first-gen-vf700-and-vf750-factory-service-manual-with-chapters-bookmarked/

Page 10-0 shows the cylinder numbers
As you sit on the bike, cylinder 1 is rear left, 2 is front left, 4 is front right and 3 is rear right

Page 18-0 shows the routing in enough detail that I think it can be used to re-connect the spark cables.
At the very least it shows that the ignition coil with the white coupling for the spark unit connects to 1 & 3
The ignition coil with the red coupling for the spark unit connects to 2 & 4

A Google search for "1983 VF750F firing order" yields this entry from another VFR site:

"Looking from the back of the bike,setting on seat. There are 2 coils.

The left coil is #1 & 3, left plug is #1 & right plug is #3 cylinder.

The right coil is 2 & 4 cyl. Left plug is #2 and right is #4 cylinder."

That said, the writer had the firing order wrong,so...

[Kdrich223]

I appreciate that! I'm going to work on it later today, I'm assuming it wont turn over because the wires were all mixed up. If that doesn't work, I'm going to clean the carbs, if all that doesn't work then I will be back asking questions! Thanks again!

[Allyance]

Not hard to figure out. Spark plug wire lengths will fall into place when you dress the front wires along right side of engine. Rear wires pretty obvious too. Follow color code in post #2, but again length of wires will tell which goes to which coils. Since there are only two coils and not four, ignition fires like a twin, firing spark plugs 1 & 3 and 2 & 4 simultaneously, it is the compression stroke of each piston that determines the real firing order. Clean and burnish connectors on the control wires to coils for optimum connection. A problem I had spent weeks trying to find after getting mine back together.

[Kdrich223]

I may not be as wire savvy as you, but I was unable to download the manual. What I'm picking up, if I am looking down the bike from the rear, the order should be 1-4-3-2? Coil on the left should have 1 & 4, and the one on the right should be 3 & 2, correct?

[ggathagan]

I may not be as wire savvy as you, but I was unable to download the manual. What I'm picking up, if I am looking down the bike from the rear, the order should be 1-4-3-2? Coil on the left should have 1 & 4, and the one on the right should be 3 & 2, correct?

Nope.

Coil on the left is 1 & 3, the rear pair of cylinders

Coil on the right is 2 & 4, the front pair of cylinders

Here are the figures I was referring to from the manual:

Odd that you can't download the manual.

There's a large green Download button on the page I linked to.

What happens if you click on it?

[Kdrich223]

Thank you! When I click download and the file is done downloading, Ill click on open, and a little red box will pop up saying "failed to open file:name:", only giving me the option to hit "ok" and close it all together. I appreciate you posting though! Ill be tinkering with it later today!