Liquifire rev limiter

[nick80lf]

Does anyone have an 80 Liquifire rev limiter that functions?

I've read here that the rev limiters can cause all sorts of problems, but I have yet to see one that actually works or causes a problem when plugged in. Years ago when I was working on the first one, I tested everything per the tech manual. I ended up installing a new rev limiter and it still did not function. I made the assumption that the NOS limiter was DOA and never did get it working.

Now 15 years later here I am again looking at the exact same thing. The sled I'm working on now had a trail fire throttle block (so no rev limiter switch). Since I saw this sled running a few weeks before I picked it up I had a good hunch this was going to give me a fit. I have a new limiter but have been leery about plugging it in because of my last experience. My wiring harness is in excellent condition I haven't done it yet but I plan on hitting the connectors with contact cleaner and dielectric grease next. I did some resistance checks and didn't see any broken wires or bad connections.

I've been looking at the wiring diagram and have a few questions / observations. I always assumed that the limiter connected the "kill" (black) wire of the CDI to chassis ground when it was limiting the speed. That doesn't seem to be possible when I look at the schematic or actual wiring. So I assume, that when the limiter is active it connects the CDI "kill" to the lighting coil which causes the spark to drop.

This makes me wonder if the wires from the lighting coil were reversed would it cause issues with the rev limiter. Remember that the newer Liquifires have one yellow and one green / white wire from the stator and the 80+81's had two yellow wires.

Also anyone have a few more suggestions, besides what's in the tech manual? If a schematic exists that shows what's inside the limiter that would be a great help also.

Nick

[smitfire]

I wonder the same..
Can a liquifires run on a sportfire?
I haven't been able to find one for the sportfire, they always seem to malfunction too

[nick80lf]

So.....after thinking about this for awhile I decided to install a NOS rev limiter and see what happens.

I was amazed ...... it functioned (at least at 4000 RPM). One down one to go.

In the back of my mind I wonder if I have a flaky CDI on the other sled. Besides never being able to get the rev limiter working, it doesn't seem as responsive, its' boggy at low RPM and would never start when the temp is in the upper 80's like today.

[3JDTIM]

i have had the same problem i just unhooked it is this ok?

[nick80lf]

The engine will run fine with the rev-limiter unhooked. You will just not have the added protection. The limiter has two purposes first; if the carbs would freeze open when you let go of the throttle the RPM should cut back to about 4000 (less than clutch engagement). Second it’s supposed to limit the max RPM to 9000 RPM.

On the plus side I did get both limiters to function. The sled that has given me grief for years I recently replaced the wiring harness connector that plugs into the limiter and it worked on the first attempt. Also, a flaky fuel pump was causing the bog.