350 PV lacks power all of a sudden

[airic22]

Hello all! I have an '89 "R" that I absolutely love. I've done a lot of things to it and I have learned a lot, but recently it's top end power left all of a sudden, like the flip of a switch and I'm not sure what to check next. Here's what I have and what I've done:
CT Racing 350PV cylinder, 39mm carb, K & N, Lightened flywheel, Cascade silencer (head pipe is fat, but I don't know the make), Ricky Stator high output, trail-tech lights, stock cdi, coil, rectifier, run/stop/light switch and stock timing.

So when it acted up, I noticed that the rear tail light "flickered" constantly regardless of where the light switch was set and the front lights didn't work at all. Assuming the problem was electrical, I replaced the cdi with a new OEM as I've had problems with them before. No change. I'm wondering if perhaps my "high output" stator could have damaged my start/stop/light switch??? It is less than a year old and OEM as well, but I don't want to buy another just to find out that it's something else. The entire electrical system is fresh as it was replaced when I had my previous cdi issues last summer.

I've got less than 10 hours on a fresh top end that ran rediculously good.....so I haven't dug into mechanical items yet. I'm still holding onto hope that it's electrical. What should my compression be? It's got the "stock" CT350PV dome and gaskets. I'm assuming that's the first thing to check mechanically. I've read that a cracked balancer bearing, spun crank bearing, or cracked flywheel could throw the timing off at higher rms's also....say it ain't so! It does start and run at lower rpm's well, just not nearly the same arm ripping powerband it had before. Any words of wisdom from you pros out there would be greatly appreciated.

[Honda 250r 001]

hmmm i had this very same problem, only mine would just mis on the top end. it was the shi tty dyna ignition box.

Did you try a new plug? haha i just gotta ask because you dont know how many times its happened to me. buy luckily i hadnt bought a new cdi before i thought of it haha.

Check your reeds, my R acted exactly like this also when my reed petals cracked and broke. If the reeds are good then maybe its your coil check that with a ohm meter.

[airic22]

Thanks for the advice, I'll check my reeds first thing after work tomorrow. Funny you mention the spark plug, I've been there before.....going nuts trying to get it running when I just needed a new plug Lesson learned. If my problem turns out to be reeds, any advice on my lighting situation? The fronts still don't illuminate and rear flicker constantly regardless of the switch. Thanks!!!

[4WHLr]

Double check the wiring harness ground wire to frame connection as well

[airic22]

Well first I checked my ground connection and everything was tight and clean. I sanded it a little just for kicks. Then I pulled the reed cage and they look "ok" I think. I could not see any sunlight while looking through it and the petals looked crack and stress free except for one of them which was frayed slightly on the tip of one corner. Would that be enough to cause my symptoms? I want to order a new set just for good measure.....these are aging. Any brand suggestions? I have v-force 1's currently, are 2's or 3's any better? Or Boyesen? Also when I go to check my coil, how many ohms should it register?

[airic22]

Somebody? Anybody? I would like to get my baby back into top shape. I'm having trouble finding replacement reeds and I'm ready to get a whole new cage. Should I go with v-force 3 or a rad valve? Anyone know a good builder in western WA?

[jhtrx250r]

What PV is your set up running?, I have the rotax style on mine and at one point i had a spring issue that made it run strange.

I would bet it is the coil the last time mine went out it felt like the plug was fouled or jetting was off only at the top end,it would start run and ride but wouldent make S for power.

with the light flickering problem you are having i would check all conectors and make sure the voltage regulator isent damaged
then check your stator cover for moisture that also causes problems in the system.

[airic22]

ok, new coil on order. My fingers are crossed.

I'm not sure what "type" of PV I have. I honestly didn't know there were different ones. Mine is anodized a dark blueish purple color and I've never had it apart. Should I? I may have gotten bad advice from the guy I bought it from. I've never had one before and I asked if there was anything to do to "maintain" the PV and he said no just let it be.

Stator cover is coming off this afternoon to check for moisture. I'll post what I find, if anything. Thanks!

[yamahay]

If you've never had the PV apart there's a good chance the PV is stuck in the closed position which will kill top end power yet have no effect on low end. On our Rotax sled engines we usually clean before season starts and once during the winter.

[airic22]

Well I pulled the PV off and everything appeared to work normally. Keeping my fingers crossed that my coil was bad, replacement is in transit.