Built a new motor and it's cutting out. I've tried everything I can think of

[suspension101]

I just built this motor with a new crank, piston and camshaft. It's a 2008 450R on a 2005 chassis and it starts first kick and idles perfect. The problem is when you get to around 5000 RPM it cuts out just like it's hitting the rev limiter. I cut the harness down into a race harness (running the bare minimum and no TPS) and the carburetor on it cam off of a motor with a similar build. The head is brand new porting with a new valve job and new valves. I've also installed a brand new Dyntek CDI on it. The engine will also hit an early rev limiter with it in neutral too. Here is everything that has been tried so far:

New spark plug
Removed race harness and installed a completely stock one with a TORS bypass installed in it.
Switched to a CDI off a 2012
changed the coil from the 05 to an 08 known good one
changed the stator
changed the flywheel
removed the CRF FCR Carb and installed a known good carburetor off an 08 TRX with TPS and hooked the TPS up with the stock harness
changed camshaft to a different grind number
dropped main jet by 20 sizes
raised main jet by 20 sizes


I've totally exhausted everything I can think of to try. I'm open to any thoughts

I'm going to attach a picture of what the race harness looks like. It's exactly the same as this minus I don't have the gray/red wire hooked up because the Dynatek doesn't use this entire plug on the 06 up. But when I installed the 2012 cdi to the race harness I ground this terminal or the bike wouldn't start.

http://www.atvriders.com/vbb/attachment.php?attachmentid=1718082732&d=1299895555

[MR.BIG]

I had a similar issue this year. If you have a tether switch disconnect it. I had a pro design on mine and it went bad. I would get to about 3/4 throttle and the thing would just start breaking up and missing. It was shorting my coil out at higher rpms.

[CJM]

Reminded me of several different threads on trx450r.org, similar situations. In there cases, although maybe a few replaced the stator the stator was still the culprit.

[suspension101]

I've had a bad kill switch do that too. But this one isn't plugged in so I know that's not it but thanks anyways

[suspension101]

I think I may have figured it out. I was way off on the rpm I thought it was doing this. When I hooked up a tachometer it was making it to 8700 then started cutting out with the dynatek CDI. With the setting I'm running it on it shouldn't hit the limiter until 11,400. I plugged in the stock CDI with the TORS wire hooked to ground and it would hit around 10500. So I think the brand new Dynatek CDI is bad. I never rode it with the stock CDI hooked up and once I did its still cutting out in 1-3 gear. So now I believe it's a gearing problem. I think I had 2 problems - Bad CDI and too low of gearing.

I'm going to change the gearing and Il'll post back here for someone having the same problems later on.

[CJM]

I also have a dynatek non programmable CDI, it wouldnt let me rev it out. Swapped stock back in, no issue. Damn CDI also advanced the timing slightly thru ignition-kickback was REALLY bad.

[suspension101]

This one kicked back sometimes too. It's pretty bad when right in the instructions it had a diagnostics of how to diagnose their cdi being bad.

[CJM]

Mind linking to or putting those instructions up if you dont mind?

[2001400exrida]

I run a dynatek cdi. Only have 2 races on it but it definitely raised the limiter some. I've heard dynatek is the only way to go with the 04/05's. apparently any of the cheaper brands are just snake oil.

suspension 101, i had this same issue on my 05 and could not figure it out, i switched cdi's, played with jetting way too much, check coil, electric, and switches. I broke down and bought a new stator and put it in and it fixed my problem. I tried a known working stator and it fixed the issue so I went ahead and bought a new one.

gearing should not cause you to cut out, even very drastic gearing won't cause your motor to cut out.

[suspension101]

Here's a link to one on Dynatek's site: http://www.powercommander.com/downloads/Support-Released/Dynatek/Manuals/DynaFS.pdf

[DnB_racing]

I think I may have figured it out. I was way off on the rpm I thought it was doing this. When I hooked up a tachometer it was making it to 8700 then started cutting out with the dynatek CDI. With the setting I'm running it on it shouldn't hit the limiter until 11,400. I plugged in the stock CDI with the TORS wire hooked to ground and it would hit around 10500. So I think the brand new Dynatek CDI is bad. I never rode it with the stock CDI hooked up and once I did its still cutting out in 1-3 gear. So now I believe it's a gearing problem. I think I had 2 problems - Bad CDI and too low of gearing.

I'm going to change the gearing and Il'll post back here for someone having the same problems later on.when i did similar motor mods to mine, I went from stock gearing(13/38 if i remeber right) to a 14 front 37 rear and still had plenty of bottom end, could probably got to a 36 rear,

but ya it wound out very quick with a good cam and light piston and some compression, you will love the quick acceleration you can get with the right combination..
but it sounds like you got it figured out...FYI i never had good luck with anything but OEM cdi, as you said you can get at least 10500 to 11000 rpm before rev limit with the pink wire grounded (green wire mod)

i trust my cam for my combustion, I dont need to vary my ignition timing depending on rpm only unless your running FI with a few more sensors,IMO its not as reliable as the stock timing curves