Better throttle response

Was wondering what to do to achieve a better or snappier throttle reponse for my 04? Not as responsive as new machines.

Simply adjust cables?

Nothing major though, trying to keep it low budget.

Thanks,

Marc

How many hours on your piston, when is the last time you changed it out?

A fresh piston using the dry rebuild method will really give the bike some snap back. Along with cleaning out the exhaust port of the head and getting all of the carbon junk out of there.

Old piston = not very good power.

Stock pistons last around 40-50 hrs. But the rings are well, well worn by then. You can re ring them every 25 to keep the performance up. Aftermarket pistons such as the JE I have in my bike will last you longer. I am going 20-30 hrs in-between re ringings, I think it will last me 60-90 hrs.

Here is how to do the dry rebuild:

Hone the cylinder (ball hone or brush hone) in soap/water. Clean out with break clean and paper towels until there is no black on the cylinder. I have a 3.5” ball hone in 180 grit.

Wash the piston/rings in soap/water, spray off with break clean and let air dry.

Install the rings on the piston. Use proper ring staggering - follow the manuals staggering method - Be really careful not to get any oil residue on the piston, rings, or cylinder. Keep your hands wahsed

Install one clip on the piston. - the right side one.

Install the piston on the rod, use a light coat of oil on the wrist pin only.

Install the other clip, be sure not to get any oil residue on piston/cylinder.

Install the piston in the cylinder. Compress the rings with your hands and very carefully install it. Be sure that the oil ring doesn't bend over.

With the motor together, and no crankcase oil rotate it 50 times. Then fill with oil and check all fluid levels

Do not start the bike until you intend to ride it. Start it up, let it warm up good, go ride it hard with engine breaking, this will ensure the ring seal.

You want better snap?? Send the carb to Tokyo mods. For $250.00 they will do some mods that will make that sucker rip. :thumbsup:

yeah alot of these older bikes have issues with the accelerator pump linkage. Its controlled strictly by springs. I think ARP sells a new spring that has twice the strengh of the stock spring. I know this will help. I hard wire my AP linkage and use a bigger caliber ap blow off jet or whatever you call them.

Do the AP mod

Purchase a R&D power pump for the FCR carb. I found one on E-bay for $84 bucks. It has the adjustable leak jet and the stiffer AP spring with it - thus you don't need to do the AP mod. Put that on and start with the ALJ screwed all the way in - full AP squirt - or max squirt. Start the bike and slowly back the ajustable leak just (ALJ) screw till the bike sound like it's at it's snappyist setting from a throttle response perspective. Ride it and see how it works under a load. Once you've found the best setting pull off the sub frame and adjust the AP timing so that it just barely nicks the slide when you whack the throttle open. Put it back together and re-test it. Adjust the ALJ as needed.

These are well worth the money and really do work once you set them up. I can tell you the squirt from the pump is much stronger than with out it. It will make the bike bark when adjusted to your personal engine. AND, you'll now have the adjustable leak jet which is very nice - no more pulling the bowl off (which is a REAL pain).

Peace

alot of bikes bog from too much of an AP squirt too, the motor will rich stumble for a secend acting as it were a bog. You have to have the proper squirt, not to little or too much.

try the white brothers jetting kit...it makes a huge difference...you can snap the throttle and there will be NO bog...it works

you could get a carb kit they can cost from 50 to 200 and increases the snap quite well

If you haven't already done it, before spending a whole lot of dollars you should adjust your fuel screw, 1/4 turn can make a big difference to off idle throttle response if its not right.

If you haven't already done it, before spending a whole lot of dollars you should adjust your fuel screw, 1/4 turn can make a big difference to off idle throttle response if its not right.

1/4 turn in or out?

i did the Oring and adjusted the fuel screw like 2 turns in and noticed no improvment......WHY?

I really like the response on my 2005. It has absolutely ZERO bog. I can go from idle to rev limiter with no bog at all, it's like it has efi.

1/4 turn in or out?

That depends on wether it's lean or rich. Look in the stickies in the jetting forum for how to set the fuel screw.

i did the Oring and adjusted the fuel screw like 2 turns in and noticed no improvment......WHY?

What prompted a 2 turn fuel screw adjustment? I would guess you went from a rich bog to a lean bog by moving so far.

How was the ap timing?

I really like the response on my 2005. It has absolutely ZERO bog. I can go from idle to rev limiter with no bog at all, it's like it has efi.

My 06 is that too.

Low budget on an 04, good luck.

AP mod or JD Jetting.

You want snap like the newer machines, Change the head to an 07, enough said.

yeah like what bodyman said the 07 head is a major improovement...that and id try to get the 08 cam while you have the bike apart

Low budget on an 04, good luck.

AP mod or JD Jetting.

You want snap like the newer machines, Change the head to an 07, enough said.

I put an 07 RHC head (SS valves)on my bike last October.....the power is there, that's not the issue. But I just feel like I could use a little quicker snap, I probably just have to take a little slack out from the stretched cable.

Once warm, my bike will not bog either which is awesome!!

What prompted a 2 turn fuel screw adjustment? I would guess you went from a rich bog to a lean bog by moving so far.

How was the ap timing?

i was getting to touch the little plastic arm like that guy said, i did not make it bog, it dident do anything lol

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