This Is Driving Me Nuts Help!!!!

[porscheguy944]

1. I just bought my son a 1988 trx250r stock?
It has a 1986 stock cyl on a 1988 bottem end no porting done to it at all.
34mm kiehin carb PJ flat slide
foam filter cone type?
no lid on air box
psi pipe dont know what type lable is missing but it is large and section welded type w/psi silencer on the end the guys at psi say it is a mid type of pipe.
br8es plug
carb says PJ03AWYG on it
162 main jet (it had 152)runs like crap iether way
58 pilot (it had a 42)runs like crap iether way
needle is a NR1468 still in it and sudco says it should be a DGW?
air screw 3/4 turn out
needle in the 3rd position also tried 4th position no change
It had the stock reed cage and metal reeds
Now it has new boysen reeds and just added a reed spacer (I hope this stuff helps)
not the carbon fiber ones
I live at 960 FT in MN and today it was 60F
145 -148 psi comp W.O.T many kicks until no more rise in comp reading
can anyone help with the jetting for this thing?
does not stay ideling for long

revs right from idel though and then lean bogs????

then mid range picks up and clears out revs out

then gets to lower range of high rpm well and then runs out on top end again????
WTF ????

Can anybody tell me what this issue might be.
I have run the jetting it came with.
A).152 main
42 pilot
air screw out 3/4 turn
Needle nr1468 (stock?) 3rd position came with this jetting in the carb.
B.)162 main jet
52 pilot
nr1468 needle 3rd pos and then 4th position round two.
C.)
stock 1988 honda jetting
158 main
48 pilot
nr1468 needle 3rd pos round three

none of this had much effect and then changed to a br9ey plug then to a br8es plug nothing realy changed much same bog in the same places on the rpm range.
I PULLED THE CARB AND SOAKED IT OVER NIGHT IN CARB CLEANER AND THEN BLEW IT OUT WITH SHOP AIR AND STARTER FLUID IT IS ALL CLEANED AND THE JETS ARE ALL NEW!!!!
I ALSO CHECKED THE FLOAT AND IT DOES NOT HAVE ANY HOLES IT IT AND SEEMS TO BE SET CORRECTLY.
@@TELL ME HOW TO CHECK IT YOUR WAY AND I WILL SEE IF THAT IS THE ISSUE?@@
I THINK IT IS GOOD AS IS BUT MAYBE IM WRONG??

D.)I then put in new reeds from BOYSEN and then added a reed spacer after that still no real change???I am out of ideas?????

I checked for boot cracks/replaced reeds /replaced spark plug/checked for intake leaks with starter fluid and found none/tried another cdi but it was a bad cdi so no help there the second cdi would not even start the atv it must be a dead one?
I would like to get this set up to run right first then switch to the second set up when my son gets used to this power level.
<<<<<<<<<<<<<<<<<<ANY HELP WOULD BE APRECIATED>>>>>>>>>>>>>>>>>>


But I would like to figure this out first.
THE STOCK CARB SETTINGS????
IS THE JETTING THAT FAR OFF????

can anyone tell me what the stator should read OHM'S RANGE
and where to do the readings
at which wires and what color they are
and what the readings should be
I think this is where I should be looking next as the jetting did not help?IDK

################################################## ###########
AFTER I GET THIS FIGURED OUT I WANT TO RUN THE SECOND SET UP AFTER HE GETS USED TO THAT POWER LEVEL.
HAVE A PSI PORTED 1988 CYLINDER STAGE VII WITH PAPER WORK .040 OVER SIZED PISTON
I WAS TOLD BY DUNCAN RACING THAT I SHOULD RUN A 38MM PWK OR PJ CARB WITH THIS ET UP.
SO I BOUGHT A 38MM PWK FLAT OVAL SLIDE CARB OFF OF EBAY IT HAS
175 MAIN JET IN IT AND A 60 PILOT NOT SURE ON THE NEEDLE YET ITS IN THE CARB CLEANER BUCKET NOW SOAKING OVER NIGHT.
SAME ENGINE 1986 BOTTEM END 38MM CARB PSI PIPE AND SILANCER AIR BOX NO LID
MN 960 FT TEMP AROUND 60F
WHAT SHOULD THE BASE LINE JETTING BE SET AT WITH THIS COMBO????
THANKS AGAIN GUYS FOR ANY HELP

[wilkin250r]

Originally posted by porscheguy944
can anyone tell me what the stator should read OHM'S RANGE
and where to do the readings
at which wires and what color they are
and what the readings should be


I can't help with the jetting on that 34mm carb, but I can help point you in the right direction for electrical work. At the top of the 250R section, you'll see a thread titled "MODS and Tech sticky". Inside you'll find a link for a thread on checking your electrical system.


http://www.exriders.com/vbb/showthread.php?s=&threadid=196555

[porscheguy944]

Thank you very much for the helping hand on this one.
I listed the jetting spec's I was given for two model years from three sources.
************************************************** *
Honda oem
1986 stock Keihin 34mm carb spec's
152 main 48 pilot and a nr1468 needle 3rd pos
************************************************** **
Honda oem Keihin carb 34mm 1988 -89
158 main 48 pilot nr1468 needle 4th pos
************************************************** **
duncan racing Int
1988 /34mm kiehin carb/ no lid/mx mid to high pipe type 6
162 main 60 pilot and nr1468 needle 3rd pos
************************************************** **
Duncan racing int
1986 34mm keihin carb
158 main 48 pilot needle nr1468
no porting but after market pipe non metal (stock reeds )
fiber type reeds (like boysen)
then go up two sizes for the pipe and airbox lid off =
(162 main 52 pilot and needle in the 4th pos)
************************************************** **
SUDCO keihin 34mm no air box lid mx style pipe and silancer
162 main 60 pilot DGJ needle 3rd pos
************************************************** **
all specs are for 50F - 70F @ 960ft

I hope this helps somone else out on these settings.........

[leager-n-ky]

Have you tried opening your air screw more ?

[porscheguy944]

yes I have had it from 3/4 out to 2 3/4 out with no real change in rpm or reducion in the bog factor either.

[wilkin250r]

You might do a leakdown test, see if you have an air leak. A leak could cause all sorts of weird problems.


http://www.exriders.com/vbb/showthread.php?s=&threadid=265369&highlight=leakdown+tester


The plans don't have to be exact, you just need a way to seal the engine, pressurize it, and monitor the pressure accurately (so a 100lb pressure gauge wouldn't give you the accuracy you need at 10psi)

[porscheguy944]

I have a zero to twentyfive psi gauge and a regulator and a hand pump.I was thinking of doing a leak down test at 6psi for six minutes as they suggest on duncans web sight under leak down testing.I just thought I would start with the jetting first.

[250Rrebuild87]

I had the same prob sounds like your having i have an 87' stock motor running airbox no lid with uni foam filter i finnally got it running right 175 main 55 slow clip on the 3rd groove the plug makes a big difference if your running the 8 all you should need make sure it has the br8es the R is very important air screw about 1 1/2 to 1 3/4 turns out

[porscheguy944]

I put in the 38mm kiehin carb and it started right up and almost ideled right off the bat.It has a 175 main 60 pilot and a nr1375 needle (I think it was nr1375) I will have to check that again hard to read with these old eyes.I will post later after it quits raining.I must ride it now but it felt crisp right off idel in the garage.

[C-LEIGH RACING]

Chunk the resistor plug & put in a regular B8ES, set it at 0.018 gap, then check the inside of the silencer & make sure the inner core not broke loose & blocking the outlet.

All of those main jet numbers are way to low to me.
Neil

[morse250r]

i have a 353cc with a 55 pilot and a 168 main 40.5 carb

[porscheguy944]

thanks guys for the comparasons but I need to hear from some one with the same set up to see where Im goimg with the new carb and jetting ....Anybody close to what I have???