Hi,
I am finally trying to start my completely re built C15S SCRAMBLER without much success.
When kicking over there is little sign of anything happening.
There is a brand new carb fitted, I have a really good spark but wondering if the PVL electronic unit is set correctly, I have tried setting as recommended 2 - 6 mm BTDC with no luck.
Does anyone have any experience with fitting this PVL unit to a C15 ?
Thanks,
The installation looks straightforward according to the instructions I've just read and the only two things that can go wrong are:
1. You use the wrong timing mark on the stator - in the case of a C15, I assume you need to use the anti-CW mark?
2. You use the wrong static timing position for the crankshaft.
The advanced ignition timing setting for this C15S should be 33.5 deg BTDC. If the amount of electronic timing advance provided by the PVL ignition module is X degs, then the crankshaft must be set at the full retard position (33.5 - X) degs BTDC. However, it sounds as though you are using the fully advanced position of the crankshaft to set the timing.
The PVL instructions I've seen talks about an electronic advance X = 37 degs. It would be interesting to know what it is for this C15 unit?
I should have added:
3. You are using TDC on the exhaust stroke rather than TDC on the compression stroke.
Hi,
Thanks for the info.
I am confident that I have used the correct mark's on crankshaft and a/c direction . I haven't got any mention of degrees in the instructions I have except setting between 2 -6 mm before TDC. I am using TDC when both valves are closed, both tappets loose, is this correct?
For reference, 2 & 6 mm BTDC for a C15 corresponds to 17.5 deg and 30.5 deg BTDC, neither of which makes much sense. The correct advanced ignition setting is 33.5 deg BTDC.
For many of these EI systems, the timing is set relative to the fully advanced setting - in other words for a C15, you would turn the engine to 33.5 deg or 7.14 mm BTDC (both valves closed) and then align the magnetic rotor with the CCW alignment hole or mark.
However, the only PVL installations I can find seems to set the timing using the fully retarded crankshaft position. What would be useful would be to see a copy of the PVL installation instructions that came with the current EI system if that is possible?
Hi
When I purchased the bike the ignition was already fitted, no instructions, I've had to Google PVL and download from their site.I feel this setting is my problem, I have tried between 2 and 8 mm without really any success . I have had the bike trying to fire and sometimes a bang from the exhaust and carb, also kickback from the Kickstarter, these have happened at different settings so I suppose something is trying to happen.
From what I have read, some PVL EI units come with modified timing marks that have been set up for a particular BSA single. It would be useful to know whether this is the case with the EI unit in question or does it correspond to the diagram below?
My best understanding from the PVL instructions I have read is that the timing is set using the fully retarded ignition setting. It would therefore be worth trying this to see what happens. Essentially, a good starting point would be to set the engine at TDC with both valves closed and then rotate the stator to align the CCW timing marks.
Here's the diagram!
Hi
Yes, they are the diagrams that I have.
I will try the initial setting as you suggest and see what happens.
Knowing what I have , new carb with initial settings so I have fuel, really good spark, flood the carb. Have a valve lifter and air slide fitted, can you suggest what else it could be apart form the electronic unit setting ? Maybe the way I am trying to start it ?
Thanks,
I think the big problem you have is not knowing enough about the PVL EI system to be able to set the timing properly. However, if you set it up with the piston at TDC on the compression stroke (both vales closed), one thing you can try afterwards is to slowly rotate the engine from BTDC towards TDC on the compression stroke and note at which point the spark occurs, for example, relative to the timing marks on the EI stator and rotor. If it occurs when the timing marks align then you will know these are fully retarded timing marks. However, if the spark occurs 20-30 degs before the timing marks align, you'll know that these are fully advanced timing marks.
It would be nice if they turn out to be fully advanced timing marks because you need to do is to align them when the engine is 33.5 degs BTDC. Unfortunately, if they turn out to be fully retarded timing marks, the difficulty will be trying to work out how much electronic advance (X degs) the EI unit provides. I've seen various figures ranging from 21.5 to 37 degs and you will need to know what it is to be able to set the piston position - basically, to 33.5 - X degrees.
Hi
Alas, still no luck in starting my C15.
I have tried all suggested with no change, I have a new carb which the tickle works fine and a nice blue spark, I have tried the PVL EI setting between 20 - 33 degrees and do get sometimes a pop in the carb and exhaust pipe and the kickstart kicking back but no engine start.
I have heard that sometime some engines don't like to be flooded and have tried playing around with the air control, open / closed in between.
I feel it is the timing but as I do not have a number to use for the setting it is just trial and error, a question, what tolerance would you have for the timing for the bike to start, trying to see if this is the real problem or something else. Any further suggestion would be greatly appreciated.
Regards, M
is the plug dry?
i would try putting some fuel in spark plug hole (only a small amount tsp approx), and try again,
pvl are good ignitions
;)
and try air screw right in
It sounds as though it is not the carb assuming this is new and has the correct jet settings?
Assuming the problem is more likely to be the ignition timing setting, I would simply back the timing off roughly in 5-10 degs steps and see whether you get to the point where the engine fires up. My gut feeling is that the ignition timing is far too advanced!
If all else fails, I would be happy to pop in and have another look on my way back from the Lakes in a few weeks time - it must be a year since I last saw the bike!!