What year is your bike? If carbureted, has the carburetor been jetted? If EFI have you done the ECU modifications B&B has found are needed?

If you leave the ACR in stock position with the MCM cam timing change, it makes starting hard, no matter whether it's a 250,300,330, or 351. The MCM also changes the timing of the ACR opening the one exhaust valve. Go back to stock cam timing or press the ACR out and retime it. The information is in the MCM thread if you look long enough, quite a long thread. Personally I'd go back to the stock cam timing or figure out if the ACR is the actual reason for hard starting, with a carb it may be jetting, with EFI it is the ECU.

After you put the cams back to stock then reinstall the spring on the ACR to activate it. I will tell you whatever ticking you are hearing, if the engine is spinning more than 1000 rpm it won't be the ACR clicking. The shoes are in full out position and will not move once past around 1000 rpm - and that's with the spring. If it starts hard then, you need to look at your carburetion or if EFI you need to get the necessary changes made to your ECU. How you do that I don't know, my bike has a carburetor. Others here can tell you how to deal with it.

 

Thx klx678 i have 2018 carby klx 351 with tm33 pumper 42.5 pilot and 142.5 main jets recommended by Bill at the moment iam running it in but just before fitting BB351 i had removed Kacr off cam when doing MCM mod with 250cc bore.
the 351 starts alright but iam just wondering if its to much on the starter with the kacr not activated
what set up do you run on yr klx ?
cheers jimbo

 

I figure having the engine spin over 20-30 seconds with the original stock jetting and setup can't be easier on the starter than having the bike fire up in 3-5 seconds with a bit more compression. Besides the compression release only works at the lower rpm, 600 and below I believe. The ACR release serves the same purpose as a manual one, helping the engine get over TDC compression in the first spin, gaining a bit of momentum with the crank to fire up. It does not engage at starting and running crank speeds. If you turn the idle down too far you will hear it start to click and eventually the engine will shut off since all the compression is leaking off every time the ACR opens the valve.

Like I said, even some 650 riders took them off their 650s. Some riders had the rivets come loose allowing the shoes to fall off, with engine damage following. Knowing that and the fact that the MCM called for disabling the ACR I just fixed it disengaged.

So no, I don't see any problem if the engine spins over and starts just fine.

 

Hi klx688 thx for repli i will fit another Kacr unit to my cam iam running mcm on my 351 i like the low end torque its where i ride iam mot big on WOT anything but i have noticed the starter working a lot harder especaily when its hotter so i was wondering if anyone had photos of ACR MOD done on the MCM mod ive read Marcelino's first page on this but its missing photos of him doing this Kacr realignment for the MCM he talks about moving 6-7mm but marcelion moved it 8-9mm for a little more compression any help with pics please
cheers jimbo

 

I don't have the pictures of the ACR relocation. I can't help there. I'd say you might just pick up a used cam, 2012-2020 is what the parts list shows will work. They aren't cheap. If the bike turns over and starts fine I'd say run it. I doubt you will have any starter issues. The brushes and other small bits are available from Kawasaki. Only item that isn't is the armature, but the brush contact area can be ground a bit if ever necessary. I did a starter on my Nighthawk S and it wasn't too difficult.

 

Hi klx678 after getting to page 90 /116 on cam mod thread lol iam relising iam one of very few who is running the mcm mod on new 351 but i have been extra careful in start up n run in and nothing 5000rpms and 10 min warm up before going i have another full set of cams with kacr comming for 50$ and i will retime kacr for mcm mod but a question in your oppion mcm the 351 or stock cam what do you recommend ?
Cheers jimbo

 

I haven't ever messed with different cams. But I will say the big bore alone will work fine with stock cams. When I was much younger I was kind of anti-big bore, thinking it could create issues that might be problems. But then as I learned more, I came to realize a big bore is just like doing a regular top end. We did a big bore on my KLX650 when one of the mechanics noticed the wrist pin fit a Vulcan 1500 piston, which was 2mm bigger diameter coming in at 102 vs 100mm. I did the measurements to make sure the piston would clear valves and head, which it did. I put 35,000 miles on the bike and after 50,000 miles total it was still running strong. I learned a big bore would work with the rest of the engine being essentially stock, providing additional torque and horsepower without any major changes. If reliability is the key, I'd say stock cams. If it was to be some kind of racing engine, then different hotter cams might make sense. I'm staying with stock cams, for me it is about getting additional power without really affecting longevity.