I have noticed a problem when starting my DS 1 out of 10 times it will make a terrible metal crunching sound since I put on the 2nd Procom CDI, I think it could be because of the advanced timing, am I correct? Any one else have this awful sound when starting some times? Or could it be the starter? It’s very unnerving to hear that awful metal stopping clunk. The other 9 times it starts right up great, in about 1 second.

I got my second Procom CDI and tried it out, the best rpm I saw was 8500. Again they advertise 1000 rpm over stock, but it is not true.
I sent the first one back because it would hit the rev limit between 8300 – 8500 rpm. The new one they sent me it hits limit at 8500 rpm, no wear near 8900 like they advertise. The unit works great when I’m flying through the trials or racing, but seems to miss a little when I'm putting around in 1st or second gear following deer trails very slowly.

 

the motor could be way too lean at low RPM. with the mods you have plus the advanced timing the power should be way up at low RPM, so more fuel is needed - larger pilot, raise needle, adjust air/fuel screw.

also check for dirty pilot jet.

 

Why would you want to twist the motor that far past it's HP peak? A stock motor peaks just below 7000rpm, a muffler is not gonna change that more than 100rpm or so, at best. Shift to the next gear, your motor will live longer. HPR says the HP Peaked at like 6,900rpm i believe. Almost 2000rpm above that seems like overkill, doesn't it? I'm not trying to be rude or anything dude, i just shift when my bike starts to nose-over at the top of a gear, usually just before. Like Arnold Swarzennegger would say "Da' Tork is Dehr." [img]i/expressions/face-icon-small-smile.gif[/img]

 

AllRedBomber,

On a long flat surface drag, you wouldn't want to "twist the motor that far past it's HP peak". However there are times when you dont want to loose momentum to shift. This is true in a dune drag for example. When I raced heavily a few years ago, I noticed that I was probably past my peak hp (with stage II components) and gearing at or around 9000 rpm. However, rather than shift into 4th for the last few seconds of the race, it made more sence simply to stay in 3rd, and rev up to 9300 rpm or so for the last few moments of the race rather than loose momentum to shift up.

BajaXRider04,

You've probably got what I call a 'dead ping'. The timing is too advanced on the low end for your current fuel set up; the motor pings, and the pre-ignition kills it. I'm just reiterating what Scooby is saying - probably too lean, and richening that up will help on the low end. Perhaps a differnet fuel may help. I ran into this problem with the Ron Wood Racing CDI while running the MrHP 14:1 piston. I didnt have the problem when running the 11.5:1 piston, so I changed CDI's and the problem went a way - Im not suggesting you change your CDI, or that theres a problem with a 14:1 piston, but merely pointing out that ignition timing curves can be different, even at idle. The cheapest fix is what Scooby suggests. Has anything else changed besides your CDI? Have you gone to a higher compression piston? If so, you'll need to move up your octane level.

Procom does advertise 1000 rpm over stock. I think they are saying that the old rev limit of the standard version was 7700 and they are 1000 over that - but thats still a stretch because they are 200 rpm short of that. Everyone that has run the Procom say its rev limit is set at 8500 rpm -

 

ScoobyDFW,
I'm not getting any poping or backfireing from a lean condition and my plugs look golden brown.
Im woried about the starting issue. I always run shell vpower high octaine gas, I think its at least 93.

AllRedBomber,
You are right It would be overkill. I seldom ever go past 8000 RPM's. It's nice though to be able to
hit 8000 rpm's with out being killed back to 7500 rpm's by the rev limiter.

OregonDunePatrol,
Nothing else has changed but the CDI. Piston and the rest of the internals are all stock.


Thanks guys for the input.
I think I might try another CDI or put my stock one back on. Or maybe I will mount both cdi 's on the ds and just use the procom one
when im on the drag strip.

 

BajaXRider04, I have consistently experienced the same loud snap sound when unsuccessfully starting the motor - I was experimenting with jetting and was too lean. As soon I went back to proper jetting the problem was gone. If the procom CDI is similarly curved as the woods CDI, then you are running FULL timing at idle, which is 27-30 degrees (not sure exactly). The OEM CDI has 11 degrees of timing at idle and the timing ramps up from there with RPM. This is done for lower emissions. Adding 15-20 degrees of timing at idle is going to create a lot more lowend torque if combined with the free flowing exhaust mods you have. The pilot jet and jet needle position will be affected most. Personally I never have had poping or backfiring from being lean, only a sucking or air gasping sound from the air filter with hesitation or stalling and sometimes with motor running hot when woods riding (fan runs continuously at low RPMs). The plug being dark does not rule out being lean at idle.

 

I'm pretty sure I heard the same sound on my 2003 Baja when I was tinkering with the jetting on my Lectron carburetor - richened it up and I've never heard it again. Start with your jetting it is cheap to do and if you are running lean you could be risking HP loss, or component failure. The good thing is by your comments you are probably running OK in the rest of the RPM range. Where do you have the air / fuel screw set? Have you ever checked? Try 2.5 2.75 and 3.0 turns out - no one that I know of has run anything else.

 

Thanks for the input guys! You understand my trouble totally.
This forum is great!

My current pilot jet 45 (stock).
The air / Fuel screw is still at 2.5 turns out (stock position).
My needle Jet is in the 4th position (stock).

I suppose if I put my quite core with spark arrestor back on the pipe she'll run fine, by
cutting down air flow and causing a richer idle.
But I just love the low end torque with them out. I can pull a wheelie simply by
hitting the throttle in 1st, and I was eating a 450R up this weekend.

I Believe I will start by increasing my Pilot Jet in small steps. I think 50 is the next Mikuni step up for the Pilot Jet. [img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-smile.gif[/img]

 

bajarider, i think u may be right about the cdi...
dont know if you have followed my thread about clutch sprag...but seems that everyone who has the problem of wearing out the sprag has the cdi... (i really dont think my problem was jetting as even when i ran SUPER rich it had same symptoms)

if it were me.... i would do somthing about it SOON... i always heard that load clank (sometimes just the metal griding, with the occasional not starting ending in a loud horrific metal snap) and it ended up costing me BIG bucks to fix it.... (i ended up buying another motor....but if i had bought just the parts i would have been at well over 400 bucks)

out of curiosity, was the 450r u were racing stock?

 

Roost,
The 450R was stock, he said.
Thanks for the input. That sound she makes "loud clank (sometimes just the metal grinding, with the occasional not starting ending in a loud horrific metal snap)," It shakes me right down to my bones every time I hear it. It must stop or I will stop using the Procom CDI.

I have already broken a fly wheel key and lost all spark when I was at the dunes with a Procom CDI and all I did was rev her up on the drag line. I heard the terrible loud clank along with metal grinding along with a loud snap and she was done...... Game Over. It sounds as if the motor might be trying to reverse itself, and failed.....

I think I’m going to have to have an email session with Jennifer Kobuki, Sales Manager, at Procom Engineering, Inc. again.

Maybe they will reprogram it for me and send it back, I'll ask if they can decrease the degrees of timing at idle and very low rpm.
e.g. 0 - 3000 rpm stock timing
3001 - 7500 increase degrees of timing up to max. (27- 30 degrees) on a high curve, and fade back to stock over 7500 rpm.
7501 - 8500 stock curve. Max rev limit Procom 8900 or 8500rpm on my tach. [img]i/expressions/face-icon-small-smile.gif[/img]

May be they will just send my money back and tell me they don’t want my business. [img]i/expressions/face-icon-small-smile.gif[/img] But I would prefer a working product from them.