I have torn my kx250f down to the cases, putting in a new crank assembly, really getting it ready for some epic trail rides this summer! anyway, while i have the motor down, i am trying to make any cheap improvements i can make. i have the 07 clutch springs, 07 intake boot, my friends dad who has built motors for years is doing some clean up work on the head (nothing major...i use this bike as a trail bike) and i was wondering something on the cams. Because of my budget, i am keeping the stock cams, but i was wondering if you guys have seen power gains by advancing or retarding the timing a bit on the cams. I know the honda's have been making just as much power by changing the cam timing a few degrees as you would if you put hotcams or web cams in. i also know that team suzuki flattrack is doing the same thing with their rmz motors. i was just going to see what you guys have experienced if you guys have tried it. thanks so much for all the help!!
KX250f Cam Timing
- Thread starter Racerdude
- Start date
Ol'89r
LIFETIME SPONSOR
- Jan 27, 2000
- 6,958
- 45
You can dial in the torque curve by making changes on your cam timing. Advancing or retarding your cams will give you more top end speed or more bottom end torque depending on what your riding style requires.
Twin cam engines are especially tunable in this respect. You have to be careful not to go too far or things will start hitting each other. Make sure you clay everything for clearance.
Just my $ .02
Twin cam engines are especially tunable in this respect. You have to be careful not to go too far or things will start hitting each other. Make sure you clay everything for clearance.
Just my $ .02
- Thread starter
- #3
well, i know you can most of the time get more power in an area by doing this, but i was wanting to see if anybody had already experimented with it and how far they went. man you should make the trek out east to ride that trumpet on some limestone tracks here...that has got to be a sweet ride!
Ol'89r
LIFETIME SPONSOR
- Jan 27, 2000
- 6,958
- 45
Racerdude said:
Racerdude.
Have done this on many different engines but not the KXF so I dont have any particular specs for you to go by. It is hard to do without a dyno to check your results. First you have to determine where the engine has to produce the most power. Are you looking for bottom end torque to get you off of a corner or top end straightaway speed? You can have one but not both. Using the stock cam, if you tune for one area the engine will suffer in the other area. On a 250 the changes would not be very noticable. If you had a 450, that would be a different story since the 450's have enough power to be able to move the power curve around and notice the difference by the seat of your pants.
In this respect, a new cam would be the way to go. You can keep the performance in one area while improving the performance in the other area.
BTW, that ol' trumpet has seen many laps on those Eastern dirttracks. :cool:
Ol'89r
- Thread starter
- #5
well i looked at timing the cam a bit differently like putting a pipe on it...just personalizing the power. i was wanting to get a little more out of the bike on top, it seems flat to me, but this is just my play bike, so i think i will just time it to stock specs. i really hate to dump the money for cams into it when all i do is ride a little motocross and cover a ton of ground on the trials with my friends on it. thanks for the input! keep it sideways!
