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My son has outgrown his 2008 CRF70F so I think I may buy a 2007 CRF80F for him. I have looked through the jetting sections but did not see anything pertaining to a CRF80F.

We almost always ride at Hungry Valley (Gorman, CA) that is located at about 3,500 feet altitude.

Thus, does anyone know:

1. What jetting should I run?
2. Should I use a different needle (what Honda part number) ... and if so on what clip height?
3. With new jetting and needle, how many turns out should the fuel screw be set?
4. For 2007, the fuel screw is a D-style anti-tamper type. Is there a direct fit adjustable fuel screw to use (what Honda part number)?
5. Any other simple mods for the CRF80F to improve power or handling?

OK, I just bought the CRF80F for my son. I fired it up and it has a massive bog at lower rpm when you give it significant throttle. After some careful feathering, it will gain rpm and then run OK (not great) at higher rpm. I checked the air filter (it's clean) and I checked the spark plug (it looks OK). Currently the bike is located in Los Angeles at a few hundred feet altitude and I'm guessing that it is a sign of being lean.

Thus, please send any/all jetting/needle suggestions.

Thank you,

Management

Due to the massive overflow of replies to this subject I spent some quality time scouring the internet in search of the jetting answers. This is what I learned:

1. Replace the stock non-adjustable-height needle with needle kit #16012-GN1-A41. Set clip height on second from the bottom.

2. Replace stock #95 main jet with a #100 main jet (#99101-116-1000). However, the 100 main jet is no longer made/sold so I ordered a #98 main jet (#99102-GHB-0980).

3. Leave the stock pilot jet (#35) alone.

4. Replace the stock non-adjustable (via tamper resistant D head screw) with an adjustable air bleed screw (#16106-143-620). Set air bleed 1.5 turns out, then adjust per specific altitude/weather conditions.

Let us know how this turns out. But I'll bet your jets are dirty. Carb needs cleaned. Our 80's carb gets dirty regularly. I'm sure there is something to be gained with rejetting too. Though ours ran pretty nice right out of the box with factory jetting. But then again we are at 1,200 feet above sea level.

The first thing I did was to go through the carb and clean it out. It ran slightly better, but not great.

I just installed the new jetting, adjustable air bleed and such and it is much better. While power is only slightly better, the throttle tip in and steady state is radically better.

Just did this to an 2008 that I bought for my son recently. Spot on recommendation Kiwi- Thanks! Borderline criminal how crappy they have these bikes running new; The poor average guy will just live with it as is.

Kiwi,

I know this thread is old, but I was looking for the adjustable air bleed screw 16106-143-620 you mention. That part number does not exist anywhere. Do you know of a different part number?

Kiwi wrote:Due to the massive overflow of replies to this subject I spent some quality time scouring the internet in search of the jetting answers. This is what I learned:

1. Replace the stock non-adjustable-height needle with needle kit #16012-GN1-A41. Set clip height on second from the bottom.

2. Replace stock #95 main jet with a #100 main jet (#99101-116-1000). However, the 100 main jet is no longer made/sold so I ordered a #98 main jet (#99102-GHB-0980).

3. Leave the stock pilot jet (#35) alone.

4. Replace the stock non-adjustable (via tamper resistant D head screw) with an adjustable air bleed screw (#16106-143-620). Set air bleed 1.5 turns out, then adjust per specific altitude/weather conditions.