250-500cc Some WR300 questions

I picked up a 2012 WR 300 in May. I'm loving it. I've got 45 hours on it now (mostly racing hare scrambles in Missouri) and wanted to get a few things asked as I attempt to work out the last remaining kinks.

1. Carb - I've got the stock carb running OK. Not great. Definitely a bit touchy for lately when I hit a practice lap in the 40s and then race when it's 70+ F. So, hearing how it smooths the jetting process out on it, we sent in a stock Mikuni from a 2011 WR300 (my dad's bike) to RB Designs to have the full works done on it. Well, I've spent two full days trying to get it sorted only to have to give up on it and put the stocker back on, because I know it will bog, but also that it won't seaze up on me. I went with the suzuki needle recommendation, even though it took 2 weeks to get the needle, and I literally have every needle made for this carb now. I need to get my dad's bike back together and I'm fed up with the Mikuni. I've been running Keihen's on my KDXs and KTM before this, so that seems like the way to go. One thing I do have is a 38.5mm oval bore PWK laying around (on my 2008 200 XCW). It starts out down low as a 36mm then ovals up to have the flow of a 38 on top. Any ideas on how that would work on the 300? Since it's not the full 38 like everyone seems to be using, I'm a bit hesitant to try it.

2. Pipe - I've got the stock pipe on it now. I'd like to find something that would help shift the power up a bit to give a fuller mid to top. Down low is beefy enough for all the technical stuff, but when the course opens up, the 300 just doesn't keep pulling like I'd like. As another pipe related question, does anyone happen to know the plug sizes necessary to remove the dents in the stock pipe? I'll pull it off and measure later this week, but in case anyone had that info handy.

3. Gearing - The 5 speed leaves me really wanting to grab a 6th gear, especially with the engine's desire to stay in the low-mid range. The 360 had a 6 speed correct? I thought I had seen info on this fitting the 300. Anyone have experience with this? I figure when I need to split the cases, that might not be a bad idea to swap that out.

4. Clutch - The stock domino lever was giving me crazy blisters. So, I switched to an ASV perch/lever combo. The problem is that I had to take all the adjustment on the cable to the max, and then the perch took up the rest of the adjustment. So, as the race wears on, I don't have enough adjustment. Any recommendations on different clutch cables or ways to lengthen the sheathing to give additional adjustment?

1. Call JD Jetting and get a Keihin. Taskys Metric cycle sells 2013 Huskys with the Keihin already installed.
2. The pipe for the power range you would like is a pro circuit.
3. You can do a swap to a 6 speed. It's a bunch of work, but it can be done. Search for it.
4. There is an internal adjustment on the clutch. This will also make the clutch easier to pull because the lever will be at correct angle. Just do a search, there is a bunch of information on here.

Thanks. The search on forums leaves a lot to be desired, so the confirmation that the info is there will help me to keep digging.

The internal clutch adjustment, I hadn't heard or seen anything about. I'll get on that and a Keihin ASAP. Those should get me square for the last 7 races of the year...and might help me grab some more of those excellent Husky bucks.

I'll have to agree with all that, but I like the DEP pipe the best. Mid to top is super strong and it never seems to stop pulling.

Clutch: Set the adjuster on the push rod so that the arm on the case has about 3mm of play before it hits the pressure plate. That will give the best clutch feel and switch to a Motion Pro terminator cable. You have to call them and they will make it up.

I had a 02 CR250 with the PC pipes and they were OK ... I added a 2C racing pipe top the bike and never considered the PC pipes again till I crashed the 2C pipe neck to pieces ... They are much lighter made pipes and will not take nearly as much abuse as the PC brand ...Performance just super-ceded the PCs at all RPMs ...

The 010 special catalog shows a pipe that looks like a 2C clone or whatever ... It has a long stinger on the end and will require a different silencer also making the price of the system upwards but this pipe took the 02 machine to a different level ...



Also, sometimes you can just add water to these pipes and freeze them ~hard overnight a few times to remove the dents ...

I had a similar issue with the clutch perch..... I bought a universal Venhill cable and cut it to length....
with a moose 2 position perch..... clutch pull is considerably lighter than the juice unit on my 07' KTM