VintageVmax.com

Sounds like I have common problems with my '83 vmax project...

I've got a pretty rough '83 Vmax 540 that I'm working on restoring. Its all there, but seen a better day. It has a coolant leak through the oil pump housing and now I can't get any spark. I've checked the resistances of the internal and external coils as well as the continuity of the wiring harness, so the only thing left is the CDI box. The truly frustrating thing is that I did have spark before. It even fired and ran for a few seconds on my first attempt to get it running and now I've got zilch!!! Are CDI boxes that fragile and unpredictable?

The previous owner said that he did all the gaskets before it sat for the past 12 years. It has great compression (125psi), but I suspect that the oil seal is shot. Probably have to tear it down totally and replace every thing again.

Not really sure if it is worth any additional investment, but it is a very cool machine and I'd love to have it running again. What are these machines worth in running condition? I'd think that $4-500 is about all.

viewtopic.php?f=2&t=1529

viewtopic.php?f=2&t=645

-No Spark
Two different circuits. One for lights, and one to the CDI for spark. Check the CDI for a single black wire. Disconnect this and see if you have spark. If so, it is in your kill switches somewhere. If still no spark, check your CDI, Coils, or magneto. Becareful when checking for spark by disconnecting the black wire, as there will be no way to kill the engine if it happens to fire.

Location, time of the year and of course condition all play a role in value.

Vmax540 wrote:viewtopic.php?f=2&t=1529

viewtopic.php?f=2&t=645

-No Spark
Two different circuits. One for lights, and one to the CDI for spark. Check the CDI for a single black wire. Disconnect this and see if you have spark. If so, it is in your kill switches somewhere. If still no spark, check your CDI, Coils, or magneto. Becareful when checking for spark by disconnecting the black wire, as there will be no way to kill the engine if it happens to fire.

Location, time of the year and of course condition all play a role in value.

I found the problem... bad low speed stator coil. I replaced it with another used one that tested correctly (ohms) and "viola!" I have spark.

I rebuilt the entire engine with all new gaskets and OEM seals. Solved the coolant leak and it has 125psi per cylinder. I was able to get it fired up just the other day... probably hasn't run in twenty years! I need to find out how to bleed the oil pump though. it isn't pumping oil like it should. I am running a small batch of pre-mix in the tank as a safety measure.

boyzarus wrote:

Vmax540 wrote:viewtopic.php?f=2&t=1529

viewtopic.php?f=2&t=645

I need to find out how to bleed the oil pump though. it isn't pumping oil like it should. I am running a small batch of pre-mix in the tank as a safety measure.

There is a bleed screw on the pump next to the pump's inlet port (phillips head, faces the right side of sled). With oil in the tank and some rags stuffed under the pump remove the screw. It will allow air to escape and prime the pump. The rags will catch the oil as it purges the air from the system. Once the air bubbles stop replace the screw, spray it with some brake clean to remove the oil that as acumulated and pull out the rags. The pump is primed. Some don't do this but the pump can get air locked and not pump at all if you don't get rid of the air.

Once the pump is primed put some premix in the tank and prime the carbs. To prime the carbs close the tank filler and blow (lung pressure) into the tank's vent line. You will be able to see the fuel go through the fuel pumps and fill the carbs if the lines are clear.

The find the oil pump control cable. The adjuster is about midway. Start the engine and run it at a high idle. Pull the oil pump cable apart at the adjuster. This will extend the outer cable and put the pump in "full oil flow" mode. You will be able to see the pump pulse oil up to the Tee's between the fuel shut offs and fuel pumps. Once the oil has reached the Tee's and is pumping into the lines you're done. Just make sure the oil pump control cable is adjusted properly and you're good to go.

I don't know as it's nessessary to run a full tank of premix for break in but some like to do so. More oil also means less fuel which can also be bad so be carful here. You can acheve the same thing with the oil pump cable adjuster. All the adjuster is doing is changing the length of the outer cable. The longer the adjuster is the more oil the pump will produce.

(Thanks OPSled) !