That's always my first required mod! Brillo pads are bad....

 

I can't get my front wheel off the ground no matter what the gear without considerable body language going on and throwing in some clutch action. Maybe I just need to practice more, but it's not really on my list of things I think I need to work on.

And shaves are not really a necessity, trims are good too...

 

There are other indicators.

Top speed in 4th gear. 73 with mod, 79 with out. Both with lid off.

I have a spot near my house marked off. Start from a standing stop and give er hell until I pass the next mark and note speed.

Before 351 top speed shifting just before rev limiter 67 mph
After 351 77 mph.

After changing to 15/39 73 mph
After cam mod Less than 73 until I pulled the air box lid. then 73 mph. No gain.

It IS all subjective. My bike did not run as well after I messed with the cam timing so I put it back.

When I say wheelie, I just turn the throttle. I don't get to the balance point, I just loft the wheel and when the motor winds out, it comes back down unless I screw up sooner. I will not shift and don't need to do it in second.

Nobody has to agree with me, nobody has ridden my bike. Just my findings.

I did not change the ACR back, and the bike starts great cold and better than before hot.


Your mileage may vary and all that other stuff.

David

 

Posting the findings after modifying is what this is all about. Honest feedback that comes from modifying, testing, dialing in, adjusting is what I can appreciate.

Thanks David for your results. I for one never thought retiming the cams would result in a large gain in hp.

 

David, correct me if I'm wrong, but you only did the intake cam. ...

EDIT - nevermind, I now see that you ended up doing both cams.

 

Better reread the first post in this thread.......

"Then I was thinking (ut oh) If an exhaust valve does not open for what ever reason, it pops back through the intake. SO I pulled the exhaust cam, marked and realigned the ACR. I retarded the exhaust cam by 1/2 tooth or 10.5* like in the instructions. Now exhaust valve opens 10.5* later and closes 10.5* later."

 

David you are correct in your findings , the mod doesn't bring any benefits to a 330 or a 350 . It will only bring benefits to a 250 and a little to a 300 .
The culprit is the size , mainly , and the shape in a smaller measure of the intake duct .
I'm sorry if I got a little edgy with you a few days back . I knew that my calculations were correct , I knew that the feedback I´m getting from the bike wasn't a lie , the only thing is that I didn't do the calculations for bigger displacement KLXs untill today , and , I forgot the old american saying :
" There is no replacement for displacement ! "

 

David,

Just a thought - did you retune the carburetor after the mod? If doing this mod requires jetting, fuel screw, clip position, etc, changes as well, then not doing that could regress your engine performance quite a bit. Just think about how poorly a stock KLX runs before rejetting. You could be experiencing the same thing post-mod without a rejet, and a rejet could bring all that back and then some. Being off by just a little in the carburetor settings can make the difference between a boring ride and a rocket. Again, just a thought.

 

The cam mods should require little to no jetting changes it either works or it don't the rest is smoke and mirriors.

 

Nobrakes:

Yes, I changed the jetting. It was for sure too rich, fuel mileage went down, engine was choking with air box lid on.

Bike always ran better with lid off, but I hate the noise.

Try this: Riding the bike, open the throttle to 3/4, now back it off at a medium speed. Feel the bike. IF it accelerates, more fuel can be added because that is what you are doing.

Air changes velocity faster than fuel, so by backing off on the throttle you are richening the mixture. This tells me to pick up the needle one notch.

Now same thing, except engine stumbles (you will feel it) when backing off on the throttle. Its too rich. The air is slowing down and fuel is not. Engine bogs because its getting too much fuel. Drop the needle one notch.

It works the same for the main jet except you can only mess with it from 3/4 throttle to full and full back to 3/4.

If the bike feels like its only accelerating a little or does not bog at all, then the jetting is really close. You just have to learn to turn the throttle back the right speed and right amount for what you are testing.

I have marks on my throttle for 1/4 and 3/4 at the hand grip so I can see them. 90% of my riding is done in the first 1/4 of the throttle since the 351.

David