Missing that throttle hit

Took Big Red out for a ride yesterday... My buddy was riding his CR450... I finally got a chance to compare the two side by side. I know the bikes are designed for 2 seperate styles of riding. One big thing I noticed was the lack of hit when you throw the throttle open on the 650. I understand it doesn't have a huge hit compared to the 450 since there is excel. pump. I kicked it into 2nd and gave a hand fullk of throttle expecting that front to get really light fast...didn't happen. Any suggestions to get just a little more snap out of that stock carb?

Stock Carb properly jetted
HRC Cam
T-4 pipe
Team Honda Ported Head
Milled HRC piston (milled down to pump gas)

KTM265 wrote:Took Big Red out for a ride yesterday... My buddy was riding his CR450... I finally got a chance to compare the two side by side. I know the bikes are designed for 2 seperate styles of riding. One big thing I noticed was the lack of hit when you throw the throttle open on the 650. I understand it doesn't have a huge hit compared to the 450 since there is excel. pump. I kicked it into 2nd and gave a hand fullk of throttle expecting that front to get really light fast...didn't happen. Any suggestions to get just a little more snap out of that stock carb?

Add a pumper carb.

Lose 100 pounds!

Edelbrock carb.
Aftermarket exhaust
De-smog if you have not already
Open up the left side plate
Clean and re-oil air filter
Check fuel screens

Boggy acceleration is either slow gas entry or slow air entry.

KTM265 wrote: Any suggestions to get just a little more snap out of that stock carb?

throw it in the parts bin NO substitution for a squirt!

assume you've done "the mods" already (jetting, floats, choke palte, & blocked the air by-pass) after those there's nothing left with the Keihin but to ride, ride, & ride some more.

But do not lose hope if you can't get a pumper right away to win the crack the throttle game grasshopper!
Know that there are some dang fast riders using that carb - in other words, change the game to see who's got the huevo's to hold it open - come visit us in the SW if you need to meet a few who can shame those riding the latest & greatest on surprisingly stock XR's (I'm not one of them, wish I was )

I have been playing around with the jetting a little and that helped some... I think part of it is I'm use to a built up ATV that is an arm puller from the start... I just have to remember to roll on the power instead of stabbing that throttle.

I have ridden both and both are 2 different beasts.

The 450 has its power right now, the 650 builds its power over a RPM range

I did a drag race on an actual dirt drag strip against a 450X. The 450X won. I have a full FMF pipe w/Powerbomb header, Edelbrock carb, opened airbox and all the goodies. He didnt win by much, but I attribute it to he had dirt tires and I had DOT tires and spun everytime I wacked the throttle. I think that if I had dirt tires I would have been even with him. In a long drag I would have just walked away.
With this setup I do 3rd gear power wheelies when I have the traction.

A trick you probably know from desert racing is to start in 2nd.

doug@dsa wrote:I did a drag race on an actual dirt drag strip against a 450X. The 450X won. I have a full FMF pipe w/Powerbomb header, Edelbrock carb, opened airbox and all the goodies. He didnt win by much, but I attribute it to he had dirt tires and I had DOT tires and spun everytime I wacked the throttle. I think that if I had dirt tires I would have been even with him. In a long drag I would have just walked away.
With this setup I do 3rd gear power wheelies when I have the traction.

doug@dsa wrote:I did a drag race on an actual dirt drag strip against a 450X. The 450X won. I have a full FMF pipe w/Powerbomb header, Edelbrock carb, opened airbox and all the goodies. He didnt win by much, but I attribute it to he had dirt tires and I had DOT tires and spun everytime I wacked the throttle. I think that if I had dirt tires I would have been even with him. In a long drag I would have just walked away.
With this setup I do 3rd gear power wheelies when I have the traction.

And I did the same drag race against the same 450X and won?

I'm thinking he's just not hooking it up at all.

husky123 wrote:

doug@dsa wrote:I did a drag race on an actual dirt drag strip against a 450X. The 450X won. I have a full FMF pipe w/Powerbomb header, Edelbrock carb, opened airbox and all the goodies. He didnt win by much, but I attribute it to he had dirt tires and I had DOT tires and spun everytime I wacked the throttle. I think that if I had dirt tires I would have been even with him. In a long drag I would have just walked away.
With this setup I do 3rd gear power wheelies when I have the traction.

And I did the same drag race against the same 450X and won?

bakeray wrote:I have ridden both and both are 2 different beasts.

The 450 has its power right now, the 650 builds its power over a RPM range

Exactily... two completely different machines. I thought that 650 was a lot easier to ride then the 450...

KTM265 wrote:

bakeray wrote:I have ridden both and both are 2 different beasts.

The 450 has its power right now, the 650 builds its power over a RPM range

Exactily... two completely different machines. I thought that 650 was a lot easier to ride then the 450...

My kids YZ450 can get you into trouble if your not expecting when its going to kick in. A couple of times I wasnt expecting it and got a surprise

Gene Lane had an interesting description of racing the 450 instead of the 650 in the recent 1000. He said something different. Here's his reply to my question about the difference:
The bike [the 450] is faster, more maneuverable and handles better. We never avgd over
40 before. Each mph is considerable.
Its faster cuz it hits, where the 650 builds speed. Yet when I got tired I
still could kinda lug it for awhile. Not like a 650 but I still could stick
it in 4th and lug. One delight I found is G outs. I learned I could hit
them as hard as I wanted and not case. On my 650 I would brace for impact.
On The 450 I progressively hit them harder and harder. ON the 450 I brace
for impact yet it didn't happen. His suspension had been redone so I don't
know how a stock X would perform in that situation.
We still have work to do on the top speed. Where jeff hit 105 mph on the 650
he was only able to get 94 on the 450 yet we still avged a higher speed.
I talked to Jeff today and he is going to buy another 450x to replace the
stolen bike and yes we are headed for the 500. Hopefully with another great
rider aboard.
Gene

KTM265 wrote:

bakeray wrote:I have ridden both and both are 2 different beasts.

The 450 has its power right now, the 650 builds its power over a RPM range

Exactily... two completely different machines. I thought that 650 was a lot easier to ride then the 450...

Bump wrote:Gene Lane had an interesting description of racing the 450 instead of the 650 in the recent 1000. He said something different. Here's his reply to my question about the difference:
The bike [the 450] is faster, more maneuverable and handles better. We never avgd over
40 before. Each mph is considerable.
Its faster cuz it hits, where the 650 builds speed. Yet when I got tired I
still could kinda lug it for awhile. Not like a 650 but I still could stick
it in 4th and lug. One delight I found is G outs. I learned I could hit
them as hard as I wanted and not case. On my 650 I would brace for impact.
On The 450 I progressively hit them harder and harder. ON the 450 I brace
for impact yet it didn't happen. His suspension had been redone so I don't
know how a stock X would perform in that situation.
We still have work to do on the top speed. Where jeff hit 105 mph on the 650
he was only able to get 94 on the 450 yet we still avged a higher speed.
I talked to Jeff today and he is going to buy another 450x to replace the
stolen bike and yes we are headed for the 500. Hopefully with another great
rider aboard.
Gene

KTM265 wrote:

bakeray wrote:I have ridden both and both are 2 different beasts.

The 450 has its power right now, the 650 builds its power over a RPM range

Exactily... two completely different machines. I thought that 650 was a lot easier to ride then the 450...

That would be largely due to the suspension differences, not just in the weight. The USD forks take the big hits much better.
But with such a highly tuned motor as the 450, it is the better race machine.

OK, had the bike in the shop and played around with the stock carb. My main jet is pretty good... The pilot is off. Looking at the side where I should see an air screw I see a round pin with a flat on it... Looks like I need a special key tool to adjust this. Anyone got one or know where I can buy one of these tools?

Next... Carb options... What are the top 3 choices?

Hey,
I'd save your money and get the stock carb to work. The money you'd spend on an aftermarket carb is much better spent on something that will really wake the bike up like an HRC cam, HRC race head, or HRC milled piston. Those will really make the bike bark is the intake is all opened up. I had heaps of starting problems with mine when I bought it (I think that's whay the original owner sold it). Finally I took it to PC (400 miles away) to have them sort it out because I couldn't. It starts so easy now I'm ashamed of my tuning skills ...

KTM265 wrote:OK, had the bike in the shop and played around with the stock carb. My main jet is pretty good... The pilot is off. Looking at the side where I should see an air screw I see a round pin with a flat on it... Looks like I need a special key tool to adjust this. Anyone got one or know where I can buy one of these tools?

Next... Carb options... What are the top 3 choices?

So does anyone know about the air adjuster screw? It looks like it needs a key of some type to turn it... Are you just using needle nose plyiers???