wr 450f with yz 450f exhaust cam installed
Posted July 03, 2008 - 07:27 PM
start and sometimes will kick back. So in order to start the bike with the electric starter I must use the above described procedure but it cranks a long time before it starts. I am wondering if anyone out there has added the yz cam and had similar problems. I think it is possibly a jetting issue , but was hoping someone may have run into this before.
Posted July 03, 2008 - 08:07 PM
Posted July 04, 2008 - 12:01 PM
Like tweav said, the OEM YZF cam is going to have a taller decomp pin and will dump more compression, factor in the fact that the WR's starter is slow and you have a situation where the motor apparently does not build enuf compression to start.
I admittedly like the performance gains I got with the cams but in hindsight, I wish I had gone with an aftermarket cam built specifically for the WR:prof:
Good thing now though is that my jetting is spot on, I've done the blu/wht wire mod and my WR starts so f'ing fast with the button it's ridiculous... as good as any other husky or ktm I've seen, it's like instantaneous and is still winning races despite the lack of the YZ cams
Posted July 04, 2008 - 01:40 PM
Posted July 04, 2008 - 08:05 PM
Posted July 05, 2008 - 05:40 AM
I forget how fast my bike is sometimes until I ride someone elses bike
Posted July 05, 2008 - 11:20 AM
the decompression pin on the yz is not taller I mic'd, it is advanced so it opens the valve a few degrees sooner . my bike starts fine but it is not as ez as it was ..
You're right, advanced, not taller.
There are so many different experiences with this mod, I just happened to end up on the bad end of the experience spectrum...
One thing that you can be thankful for fried is that you have a steel framed bike and if you choose to do a lot of jetting combos, it will not take near as long as those of us with Al frames
I would start with your pilot, if you go to the jetting forum there is a sticky on the top for checking your pilot setting using the fuel screw, it's really useful:thumbsup:
Good luck, I hope you get it to point you are happy with it:ride:
Posted July 05, 2008 - 02:10 PM
Posted July 07, 2008 - 04:08 PM
I run a 42 pilot jet and a Merge adjustable leak jet and it starts much easier but when I start it cold I kick it. It fires first kick then.
that's interesting . I also run a 42 pilot and a rd powerbowl and I can kick it the first try , or if I choke it with no throttle and the ez button it fires right up.
Posted July 08, 2008 - 08:12 AM
Posted July 19, 2008 - 07:26 AM
is grabby after it warms up it seems to engage properly. I pulled the clutch cover off and inspected and did not find anything broken or anything that looked funny except the inner clutch hub had some groves wore into it, so I filed the grooves smooth and put it back together. I also noticed that the starter clutch seems to turn hard. Has anyone run into a similar problem on one of these ktms ? thanks for your input
Posted July 19, 2008 - 08:56 AM
A good many early (pre'06) YZ450's start better cold with the throttle lifted very slightly off idle, so I don't find that unusual, but it seems to me that you should be able to get it to start by working with the idle jetting.
Then again, with YZ timing, the engine will not want to run as well or as stably at very low speeds, and the e-start does actually turn the engine over more slowly that the kick crank does, so that could be part of the trouble, too.