PVL digital ignition

I have a PVL on my 1979 RM125 and it runs great. Do you run a ported cylinder? I have a ported cylinder that I only use at large tracks as it runs terrible off the bottom. All air-cooled 125's are worthless below full throttle but this ported cylinder is a nuisance. I swap on my OEM cylinder for most tracks. I run a 32mm mikuni.

Check your grounds of course.

I have PVL's on a few of my bikes and have never experienced a problem. They are very reliable. You may have a bad one but I would be surprised if that is your problem.

I know nothing about PVL ignitions. Have you retarded the timing at all? Are we allowd to say the word retarded any more? Have you specially tuned your Igniton to fire sooner I mean?

Is the problem the PVL or carb? Have you tried going back to a 32?

From people I've spoken with, the PVL makes a positive noticeable difference with a stock engine.

http://m.vitalmx.com/forums/Old-School-Moto,22/Lectron-carbs,1281229

Check out the post by lone star

Your problem lies within your carb and not the PVL.....sounds like your a tad to fat on the pilot....where is the needle at ?

Is this the analog or digital ignition?

What spark plug are you using?

Clean and clear grounding on all the ignition touch points?

What gas/oil combo and ratio are you using and what have you tried? For whatever the reason the 1980 Suzuki seemed to work best for me at 32:1 with a 50/50 gas mix (*VP c12). I used to run Bel-Ray MC1 also...I'm all over the place with oils though and currently mainline 927 Maxima.

I can't explain why but I had new Mikuni's, rebuilt 1977-80 model RM125 carbs, and pulled carbs off my Yamaha's even. For whatever the reason that bigger bodied 1982 RM125 32mm carburetor worked like a champ. I never had a problem though with it running super high rpm's so was really curious about the analog or digital PVL. I always go back to stock jetting then start messing with it from there but I can tell that is probably first in your bag of tricks also. The Lectron is a whole other dynamic that I have zero knowledge of so I'm of no help there. If it's the analog PVL maybe my brother will jump on here and offer some advice as he is more familiar with the range of PVL's.

I would perform some quick more air less air tests, put a strip of tape across the top of the airbox , if worse remove the air filter,(more air) see if it improves, i think also someone is going the right direction regarding eletrical, did the PVL come with a resistor cap and did you install an R plug to supress the free flowing eletrons..

Going back to the carb, look that there isn't blockage with air to the needle jet.

Go with the hotter plug Mike. Move the clip up a notch and maybe a size smaller pilot.....your jetting is way off in my opinion as being the only issue. Hard to diagnose over a computer though. Porting and pipes along with the PVL changes things a bunch
From a stock setup.

I agree it's hard to diagnose over the web. Obviously porting and a pipe change things up. I also agree to take down the pilot. Suzuki's typically ran really small stock pilot jets so you could drop as low as 25. I believe my setting on the 32mm was a 30 pilot, 250 main, and a 2.0 cutaway. Knowing me I ran the clip one off the top position. If you drop the pilot you may find you want to drop the main also. I would move the main up and down one off this setting depending on the weather. The pump gas should be fine so don't worry about that but if you can get ahold of some C12 mix it 50/50. I also followed the typical Motocross Action logic and added one tooth to the rear.

As for the plug I can't exactly remember but I think I ran a resistor plug in addition to the resistor cap. I believe it was a BR9EIX (*the more expensive iridium NGK's). If it's a powder coated frame get some exposed metal ground contact action happening. It really sound like jetting though and like I said in another thread these things were a bitch to get right but once you do it's worth it.

I'm also going to assume you are running Boyesen reeds. Are you using the reed stop? If not put it on.

--albert

Have you tried to adj the bog out using the air screw, i'm not seeing anything on this circuit mentioned, 1/2 to 2.5 adj. range, then if at 2.5 go up a size on the jet and the oppsite if turned in all the way adj. in, float level is not mentioned and condition of needle and ceet, basically you need to start at the fuel valve. I have a couple of these bikes and can tell you that the DG pipe is a close copy of the origional, if you run straight c12 you will need to lean out the slow circut, the flame front just burns that slow, go 50/50 as suggested. There is some missing questions, who ported the cylinder a pro? get the specs. these can be destroyed in the wrong hands, the 80 cylinder was the best, 79 had transfer port casting issues, the exhaust is good asthe factory opened it up to what was done on previous years, it can be widened some, transfer ports let alone, here's the big gain area and what may be some of your issue, was the intake lowered this was the area for good gains, but you need to be carefull how much is removed from the intake floor or piston skirt. 3mm was the max i would lower them, however putting the piston in the bore and the piston just before the exhaust opening scribe the piston on the intake side and see how many mm of skit is covering the intake.
I f the intake was lowered to much you will be getting spit back into the incomming fuel/air charge and never beable to tune the carb properly or run crisp at low rpm. As pointed out look that a reed isn't broken.
So if the intake is open just as the exhaust is opening you will need to weld of fill the intake with Devcon epoy.
Alot said here, just quick FYI i ran 45piolit clip middle 250 main, what it you timming spec, 1.0,1.2 mm before tdc? neep to be percise measurement if you want the max out of this nice looking machine.