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Thanks for all the help. It seem to be jetted right with 240 main, 40 pilot, clip 2nd position, and air screw 1.5 turns out. Pulls hard on the powerband no hesitation. I think a lot of it was me not being used to a non powervalved two stroke. How ever I have another question. The left carb does not want to fill up the fuel line to the top only about 1/2 way. The petcock  has been rebuilt and cleaned. When I was rejecting it 10 times I noticed the fuel inlet nipple was loose. I rtv'ed it but the line still does not want to fill up completely. The right carb does. Thanks again for all the help and knowledge on this forum!

Sorry i was wrong.  The oil injection nozzle is on the left side of the carb on my RD.  Mine is missing this fitting on the right side. 

They fit but require more machining/grinding away of inside of the cylinders where the reed cages sit.  I used yz85 reeds with banshee intakes and spacers.  You still need to enlarge the area were the yz85 reed cages sit.  However, I am still trying to get my RD squared away through.   

The top pic is the oil injection nozzle.  It is not a vent. If the bike runs premix i would cap it with vacuum cap. If it does not run premix you need a new one and a ensure that the oil line is connected to the pump.  I confused the float bowls when working on mine.  The left or choke side float bowl bottom vent faces forward.  The right side float bowl bottom vent points down. 

I did some jetting this weekend.  Started with 200 mains and 30 pilots, air screw 1.5 turns out, needle clip in middle position.  The bike could pull out with minimal bogging. but was still bogging.  Once the bike is moving it does not bog.  I kept turning the air screw in till closed in 1/2 turn increments and it kept improving. Tried 200 mains and 32.5 pilots, air screw 1/5 turns out.  I kept turning air screw in in 1/2 increments till closed and it was still improving, however breaking up in high revs 1st/2nd gear.  Ended up going with 210 mains and 35 pilots with air screw 1/5 turns out (need to order more jets). Same as above kept turning air screw in and same situation. 

Bike specs: 75 rd350, bored .25 over new pistons/rings, all new cranks seals, yamaha bond (case), and gaskets, new HPI ignition no battery, yz85 reeds, and reed block spacers, banshee crossover tube, uni pod filters, stock vm28 carbs with Dave F carb mod, Jemco expansion chambers. 

I am thinking about ordering 37.5 and 40 pilot jets but it seems pretty large.  Thanks again.

you should be able to determine where the pilot jet needs to be by experimenting w the air screw. crank the screw in to about 1/2 turn, if it gets better, go up on the pilot.  anything under 1 turn 'good' will tell you this. anything over 2.5 out means you typically need to go down.

So last night I tried what you said.

The air screw was initially set 1.5 turns out.  I went in a .5 turn and it was a bit better.  Then went 1 turn in and it was a bit better.  Then I went 1.5 turns in and it was better but still bogging when letting the clutch out.  Also at this point the air screw was closed off.  I also tried turning out on the air screw and from the "stock" 1.5 turns out to 2 turns out which was was way worse as it would stall when letting the clutch out.

I  am going to put in the 30 pilot jets that i have and also order 32.5 and 35 pilot jets.   

I will give that a try hopefully today.  Thanks

I am going to put in the 30 pilot jets that came with the Dave F carb mod, and move the clip back to the middle.  I still have the 27.5's in there now.  Moving the clip was a test to see how the expansion chambers might have changed it.  I am going to try and video what it is doing.  Once i get the revs up over where its bogging when trying to start out it seems fine.  I am guessing it is still lean.  Just hard to believe with the large increase in jet size that I have already done. 

I am still trying to figure this out.  Got the bike back from Jemco.  The expansion chambers look awesome.  The bike starts right up and will idle.  I moved the clip 1 slot leaner and it appears to have have gotten worse when this was done.  What size reed block spacers are members using on their RDs. I have a set on this bike.  I was wondering what size 9mm to 13mm thickness?  Thanks

Also correct as i noticed this after i installed the carbs and reconnected the vent hoses. 

Also on an RD250/RD350 you can verify after assembly that the bowls are on the correct side. The left (choke) carb should have a brass drain tube nipple that points forward. The right carb drain nipple points down.

I was going to put bigger pilot jets in the carbs before i took the bike to get the pipes built.  I noticed that both float bowls did not have a hole on the bottom.  I had another float bowl with the hole on the bottom for the choke, and I put it on the left side/choke lever carb.  Is this correct?  I am going to start it today to see if this resolved the choke issue.

Float bowl with hole on bottom belongs on the left/choke lever carb.  The float bowl with no hole goes on the right/no choke lever carb.   

Correct? 

Thanks

I started the bike again.  It started right up and idled with choke on and off.  Idle was constant with choke on and off.  It did have some unburnt black gas oil mix leaking at one pipe/muffler connector, but i believe that this was from the other day when it did not want to start.  I want to blame the starting issue on the inline fuel filters (clear gold stone looking ones).  I do not like how they seem to restrict the flow of gas.  I am only using them as i just cleaned out the tank.  They fill the float bowls but the left carb fuel line does not fill up all the way with gas. I recently rebuilt the petcock and no flow restrictions were present.  Carbs are also rebuilt and and float level set to 15mm I think (whatever is spec in manual).   I am going to delete the fuel filters as soon as possible. 
It still does not want to pull a load without choke.  It does seem to be lean on the pilot circuit as someone else suggested.  With the way i have been running the bike i have not been able to get it up on the main jet circuit.  I am still going to verify timing just to make sure.  I should be getting the correct exhaust setup on soon to really verify the jetting.  Just wanted to make sure the bike ran and did not blowup into a million pieces before i dropped all the money on the exhaust. 

I what to thank everyone for the help/suggestions.





verify spark and that the ign rotor didn't slip. nothing else should be an issue barring an air leak. you did join the 2 cabr sback at the choke crossover?
but a slipped rotor will give hard starting and bad performance overall.
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Just thinking what i did to the bike.  Yz 85 reeds and reed spacers.  Bored .25 over.

Cases split and all new seals.

HPI no battery no lights
NGK NGK Iridium Spark Plug BR8HIX