Fork oil and jet size?

[Hendrikder]

Good Day Everyone

Can anyone please help me I have 2 questions

1 - How do I determine what size main jet I currently have in, because I want to put in a smaller jet , but I dont know what size is in it at this stage.

2 - The specs on changing the front fork oil? What oil should I use, the amount, pressure ...ex.

If anyone could please assist me.

Thank You

[K50X200]

1 - How do I determine what size main jet I currently have in, because I want to put in a smaller jet , but I dont know what size is in it at this stage.

You'll have to pull the current jet out of the carb - the jet size should be stamped on the jet itself...

[KDXGarage]

1 - How do I determine what size main jet I currently have in, because I want to put in a smaller jet , but I dont know what size is in it at this stage.

You'll have to pull the current jet out of the carb - the jet size should be stamped on the jet itself...

Exactly.

Take it out and read it.

Which bike is this?? The one in your signature, 2005?

Do you have the stock forks on it? What is your weight in full riding gear? Usually it is 5 weight fork oil for the cartridge forks.

Do you have the stock fork springs? What terrain do you ride? What is your skill level?

[Hendrikder]

1 - How do I determine what size main jet I currently have in, because I want to put in a smaller jet , but I dont know what size is in it at this stage.

You'll have to pull the current jet out of the carb - the jet size should be stamped on the jet itself...

Exactly.

Take it out and read it.

Which bike is this?? The one in your signature, 2005?

Do you have the stock forks on it? What is your weight in full riding gear? Usually it is 5 weight fork oil for the cartridge forks.

Do you have the stock fork springs? What terrain do you ride? What is your skill level?

I will pull the jet and have a look, with gear I am 240lbs, the forks are bone stock and everything in it is stock as well. I normally ride rocky and woods areas, I would say I am an average rider.

Thank you

[KDXGarage]

Unfortunately, pulling it apart is the best way. If you have a JIS compliant screwdriver, use it on the JIS screws on the float bowl. If you have an old, cheap Phillips #1 and a bench grinder, some have reported that hitting the tip just a bit will help it to settle down into the screw head better.

I am 233 all geared up. Stock fork springs and shock spring won't do for either of us. I would say somewhere around .46 fork springs and 5.4 rear shock spring. Look at what rate fork springs come on a YZ250X or YZ250FX (.44 I think). We are a good 50 pounds more than the average rider.

[bufftester]

for the stock fork, 5W fork oil, 530 ml approx volume. With spring out and fork fully compressed the oil level should be between 85-89 mm from the top. If you're changing the oil may as well change the seals and dust sliders too. That will refresh your front end, but won't solve the problem of being woefully undersprung for your weight. Get the right springs, IMO best performance enhancing money you can spend.

[KDXGarage]

Don't forget the cartridge rod bushings, inner tube bushings and outer tube bushings.

[Hendrikder]

Unfortunately, pulling it apart is the best way. If you have a JIS compliant screwdriver, use it on the JIS screws on the float bowl. If you have an old, cheap Phillips #1 and a bench grinder, some have reported that hitting the tip just a bit will help it to settle down into the screw head better.

I am 233 all geared up. Stock fork springs and shock spring won't do for either of us. I would say somewhere around .46 fork springs and 5.4 rear shock spring. Look at what rate fork springs come on a YZ250X or YZ250FX (.44 I think). We are a good 50 pounds more than the average rider.

Thank you very luch for the advice will definitely be looking into get beter springs or maybe to change the front end completely.

I toom the main jet out it is a 152, what jet size would you suggest? I am riding at 5500ft, temp getting cooler now ranging between 5 - 15 Celsius.

Thank You very much for the kind help!!

[KDXGarage]

Stock in the USA is 160.

Is there anything else going on with the bike that might cause you to run one that size?

[Hendrikder]

Stock in the USA is 160.

Is there anything else going on with the bike that might cause you to run one that size?

Mods on the bike are as follows

Boysen reed valves
Fmf Gnarly Pipe
Fmf Silencer
Air Box Lid removed

That is the only stuff I can think about that might change the jet, but in my personal opinion I am running a bit rich still. Has quite a lot of spooge and it does feel like I might use a bit to much fuel.

Thank You

[KDXGarage]

Did you dip the carb in strong cleaner?

Have you checked the fuel / float level?

How clean is the float valve? Is it worn? properly seating?

[Hendrikder]

Did you dip the carb in strong cleaner?

Have you checked the fuel / float level?

How clean is the float valve? Is it worn? properly seating?

I did clean the carb yes and the float valve is in mint Condition. I have the float height set at 16mm, would you advice changing?

[KDXGarage]

How did you clean the carb?

[Hendrikder]

How did you clean the carb?

I cleaned it with some good and proper carb cleaner, I've seen that some suggest to set the float height to 19mm?

[KDXGarage]

OK, on occasion, some have cleaned the carb with an aggressive dip which damages the jet block gasket.

Adjusting the float level is worth a try.

[Hendrikder]

OK, on occasion, some have cleaned the carb with an aggressive dip which damages the jet block gasket.

Adjusting the float level is worth a try.

I adjusted the carb and will be checking it out on my ride tomorrow.

So in your opinion you think I shouldn't go smaller on the jet?

Thank you

[KDXGarage]

Which pilot jet do you have?

Which needle?

Which position is the needle clip?

[Hendrikder]

Which pilot jet do you have?

Which needle?

Which position is the needle clip?

The needle is a R1174N and it is in the first clip from the top.

I haven't had time to remove the pilot jet but I will let you know the size when I have a bit of spare time.

Regards

[Hendrikder]

Okay guys this is what I got :

Main jet 152

Pilot Jet 42

Needle R1172N on first clip from the top.

I did a ride this weekend, trails with a bit of technical I only got 90km out of the tank with about 1L of reserve left when I got home.

I also pulled the spark plug todat, 13.4 hours after the last timed I cleaned it, it was very black and dirty.

I am runny Castrol racing 2T 40:1, 93 grade petrol.
Any advice please

Kind Regards Hendrik

[Hendrikder]

Which pilot jet do you have?

Which needle?

Which position is the needle clip?

Just want to tag you to my previous post.