PJS Viper9000 super cylinder w/total loss static timing

[GoBig]

Hi, I have a PJS super cylinder on 650 lower case. I’m trying to put an MSD 00-00-2530 total loss on it. I have a question regarding the static timing for this motor.

Anyone have an idea what I should set the static to? I have heard 25deg in a YouTube video but that was for a stock-ish 650.

Any help would be appreciated

Thanks

 

[WFO Speedracer]

The MSD is more about the timing you can put into it throughout the curve than just what the static is set to.

25 should be a starting point for initial timing .

MSD Total loss master thread

Ok here goes I know there are some guys still running these setups, the info from MSD has mostly been lost and most of the links that you can find are now dead. So I am thinking it might be a good idea to create a master thread with any info that may be still floating around out there. I will...

www.x-h2o.com

 

[Storbeck]

If msd static timing works the same way as static offset on a zeel, seems like you with want more like 30 or 35 maybe, so that you can run a curve with 30 or 32 degrees of advance in the low rpm range.

 

[kevbo]

You need to be careful with timing advance until the main jets/top screws are set rich of peak power. After that it’s safe to use a little more initially and adjust the ignitions retard curve. Nobody can appreciate how easy pistons are to burn until they do it themselves. Kawasaki’s tend to need less timing advance.

 

[WFO Speedracer]

As far as timing goes it really depends on what you are doing with the ski , most freestyle boats set up with total loss cannot be held wide open for any length of time , they are running way too much timing for that , if you are doing short burst of throttle like in freestyle you can get away with a lot of timing, if you are wanting a ski you can run wide open across the lake you have to back the timing off substantially or you will have serious engine issues.

A lot of the freestyle setups are running 35 degrees initial to get more bottom end out of the engine , that's a lot of timing to have to pull back out at WOT .

It's all about the curve , the more initial that you put in the more you have to take back out a wide open throttle , I would not go with more than 30 initial , set your rev limit at something just slightly above what the engine will actually pull in the water , if it will pull 8000 RPM set it at 8500 , if it will only pull 7000 rpm set it at 7500 .

Then you have to back out the timing after about 4500 -5000 rpm , so many degrees per 1000 rpms , you have to set the starting point you want it to start retarding the spark at and the number of degrees per 1000 rpms you want it to back out of the total timing curve .

Lets say you start with 30 degrees initial timing and you are at a rev limit of 8500 rpm, if you start at 4500 and back out 3 degrees per 1000 rpms then at 8500 you have 18 degrees of timing at 8500 rpms.

If you back out 4 degrees per 1000 rpms you have 14 degrees at 8500 rpms .

If you are set at 7500 rpm then you can only back out 9 degrees at WOT and you end up with 21 degrees at WOT, way too much timing .

If you back out 4 degrees per 1000 rpms you have 18 degrees at 8500 rpms .

You want somewhere in between that like 15-17 degrees at 8500 rpm or what ever your top WOT rpm is for safe operation .

Back in the day our MSD's were analog and used chips , I still have a bunch of that stuff , the newer digital setups with dip switches are much easier to set up.

 

[fastgtfairlane]

Gonna depend on the compression and fuel you use. Higher octane would need more timing. 30-32 degrees would be ok for pump gas as long as you pull enough timing back out by 6000 rpm. 16-17 degrees at 6k rpm. Then you can run it wide open safely without burning up a piston..

 

[GoBig]

Thanks for the responses, this is a lot of good information.

This engine will end up in a vintage x2 I race a few times a year. I think I’ll set the static somewhere around 28-30 and work out the programming from there.