2001 Xr 400 Oem carb jetting 160/60 sea level.

Hi When i bought my bike it came with a Hotcam (stage 1 i believe ) installed and the Oem carb has 160/60 jets installed and i believe the needle is on the 3rd clip I took the air box splash guard out and the OEM pipe has the 3 holes drilled not sure if the header welds were ground down. My question is would 160/60 be the correct jetting for sea level with the bikes config i haven't tried this carb yet but would like to know if its jetted right before using it?

Another thing is It is a real beast to kick over I have to use all of my weight (170 Lbs) to kick it (using the correct starting method ). I am assuming that is because the hotcam has no auto decompression but even so it seems like its really hard to kick is this normal? I did not notice any werifd noises with the bike runing.. At least i wont have to worry about people stealing it unless they have been doing leg day at the gym for a few years.

Edited by doh13

If that jetting isn't spot on, it should be real close. Tune the fuel screw for best idle and throttle response off idle.

As for starting. Always Always bring the engine to TDC with the kicker before giving a starting kick. Especially for not having an auto decomp. Does the bike still have the manual decomp connected?

As you bring the engine up on the compression stroke with the kicker, you hit a hard spot. Leaving your weight on the kicker, cylinder compression gradually bleeds off and you immediately feel the piston hit another hard spot. That detent between the 2 hard spots is TDC. Always make your swift starting kick from there. Full choke and don't give it any throttle. Be sure you're not running a low idle speed. If you like a low idle speed, then you may have to turn idle speed up half-1 turn for starting, then turn it back down afterwards.

 

Edited by Trailryder42

Thanks for the info on the jetting im glad it had the proper jets installed , hopefully i wont have to change anything except maybe adjust the air screw to dial it in ,

  I was using  the kicker  and manual decompress  and  get the piston up  to the hard spot compression then i pressed the decompress lever again and press the kick start about 1 inch past tdc  then I give it a kick with all of my weight  but dam its still a very hard kick. is that about the same is what you explained?  it just feels like its in the right position when i kick it but its still a very hard kick to turn it over. im hoping its just because of the hotcams lack of  an auto decompression.  I remember watching a few vids of xr 400s starting ant they were kicking it while sitting down i cant even think of doing that.

Edited by doh13

Do you know if the the engine has had a big bore kit put in it and what the compression ratio might be? If the previous owner put a high compression kit in it, it would affect how hard it is to kick.

An auto decomp mechanism works on centrifugal force, which doesn't start to happen until after the engine has some rotation to it. Not having one isn't going to have an effect on how hard to engine is to kick from TDC.

The first hard spot you feel when coming up toward TDC is the piston compression as it moves toward it's highest point in the cylinder. When you feel it fall into that detent between hard spots, the piston is ready to start it's way back down as the con rod breaks over centerline. 

Do this. Leave pressure on the kicker after it gets past the first hard spot, until the second hard spot bleeds off. You can tell when it just about has. Then bring the kicker back to the top and kick from there. It should be easy to kick from that point because the piston is on it's way back down and you have a running head start before it starts making it's way back up for the next stroke.

Not sure on the big bore kit the cyl looks stock to me , I do  know  that my right leg will be huge  kicking it over =) . Ill try what you said when i get ready to drive it , still the middle of winter here in NS so i cant try anything yet just trying to get her ready for the spring season.

thanks for the info.

Edited by doh13

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