help with jetting

[ants84olds]

I have an 85 250r. I had it ported. It has an fmf pipe, after market reeds, stock ignition, 35mm airstryker carb, and running an airbox with no lid. I have the jetting at 160 main and 50 pilot. I had a 55 pilot in it but it would not idle. It has very little power and when getting into higher rpms it chugs like its still too rich. I dont want to blow it up so i need a better starting point. I have put this motor together and it has been setting. Everything is new.

[Dammit!]

55 pilot is too big for that carb. A 48 would probably work. Hell a 45 should work really. You're only 1mm bigger than a stock carb. You should be able to tune it with the air screw.

On the main, throw the airbox lid on and see if it gets better or worse. If it gets better, you know you're jetting is too lean. If it gets worse it's too rich.

If you haven't read the jetting sticky yet, do so.

[Daddio]

I have an 85 250r. I had it ported. It has an fmf pipe, after market reeds, stock ignition, 35mm airstryker carb, and running an airbox with no lid. I have the jetting at 160 main and 50 pilot. I had a 55 pilot in it but it would not idle. It has very little power and when getting into higher rpms it chugs like its still too rich. I dont want to blow it up so i need a better starting point. I have put this motor together and it has been setting. Everything is new.

Was the port work done by a reputable shop and what type of port job did they do?

[ants84olds]

yes and it should be a port for all around riding. it was a member on another forum by the name of flotek.

[Daddio]

yes and it should be a port for all around riding. it was a member on another forum by the name of flotek.

I know Denny "flotek" personally. He does very good work.
My son "1upfront" has a flotek drag ported 84 300r. It has a 39mm pwk and he is running a 50 pilot with the clip in the middle and a 135 main. He isrunning this thing WOT most of the time as it is a drag only machine. I'm not saying this is what you need for your machine but it does sound like you are jetted a little rich all the way around. The best way to check your jetting is by doing plug chops. You will find tips on this in jetting sticky like Dammit said.:beer

[1BFC]

To give another reference.... I have a 310 LA sleeve with a 38PWK Air Stryker and it's running 48 low and 178 high.

Really is machine specific. I would never have guessed 1up was using a 135 main seeing as my displacement is very similar but a water pumper vs ac.

Anyway...such a black art jetting is :) Good luck with yours!

[DixiePlowboy]

To give another reference.... I have a 310 LA sleeve with a 38PWK Air Stryker and it's running 48 low and 178 high.

Really is machine specific. I would never have guessed 1up was using a 135 main seeing as my displacement is very similar but a water pumper vs ac.

Sometimes, jetting specs defy logic.

I just put a new 39mm PWK on my Tecate(open Uni filter and Bill's pipe otherwise stock, and I'm runnig a 50 pilot( crisp but not zingy) and will probably end up with between a 195-205 main since the 190 in it is a bit lean.....go figure:wondering