ive only got a little over a gallon in the engine and im already experiencing problems. whenever i rev the engine up under load the engine cuts out immediatly under throttle. ive tried adjusting all the needles and returning them to factory settings and starting over. nothing seems to help. i checked th bearings for air leaks and i have found none. i was not having these problems about a week ago and it was a lot less humid out. now with the humidity,i am having all these problems. ive tried adjusting the needle settings accordingly but i cant get it right. its also not the glow plug, fuellines, or air filter ive checked them.

You problly need to lean out the engine a little due to the humidity change . Or try running a hotter plug .

its already running around 270 and its rich. i have the low speed leaned out b/c if i richen it up it stalls due to to much fuel. i have the high speed slightly lean and tried matching the two up with the mid needle. i cant seem to get it right.

i say its running rich because it sounds and looks rich but temp wise its acting lean

Sounds like you have a needle too rich and the other too lean as the temp is up and still running rich . Try a hotter plug , what plug are you currently using ?

i was using the os p3 and now im using the rb cp-02.

Is the engine cutting out at bottom , mid ,or towards top end .

mid

You need to use OS plugs with OS cylinder heads. The OS plugs are about 1 thread shorter then normal plugs and designed for their engines. Like Dawman said try a hotter plug... a friend of mine had the same type of problem with the Nova P5X and a hotter plug fixed it.

i had a 421B that used to flame out during fuel stops & going hotter on the plug fixed that too

the V-spec always seems to run best on the OS P3 which is a very hot plug!
i'd still try a fresh plug just to be sure

it sounds like a tuning/plug issue to me

does the engine still have compression when its hot? if its been cooked it will cut out when it gets hot [:'(]

the only other plugs i've used have been Sirio which have the same taper angle & thread length, i'd have to check the exact number though

V-Spec uses turbo plugs so tthe length is not an issue.

the taper angles differ between brands tho!
i found Sirio to be the closest match

That is so true. NovaRossi and Cipolla plugs were definately different, at least 7 or 8 years ago.

How was the front bearing?

the front bearing is still in good condition i always take the flywheel off and clean it out after a hard day of running (aluminum shoes). could it be that the plug is to hot? the outside temperature around here has been in the 90s recently- wouldnt i want to go to a colder plug? i use the p3, which is the hottest turbo plug os makes and the engine is still having these promlems. i too though it was a tuning problem and i still think it may be but i have returned all the needles to factory stettings several times and started all over. ive EVEN tried going against my knowledge at tuning these engines and tried settings i didnt think would work. ive got it pretty close now though- the engine runs for about 3/4 tank extremely well and then when i pit for fuel it will flame out when i accelerate hard again ( at mid range)... sometimes it just flames out on its own when the engines under a heavy load.

Using a hot plug can cause the engine to be a real challenge to tune. I live in Miami and it gets damn hot during the summer, it forces me to run a cold plug. Im gonna try getting a medium plug because with the cold plug for the first couple mins of drving it doesnt run right, then when the engine heats up its fine, but with a hot plug its impossible to get the tuning right. i think the Med plug will be the perfect middle ground.

where is your MSN? the only time i've ever had problems with tunning this engine is when the msn was wrong. A part from that it runs fine and never stops no matter if its a bit rich or a bit lean it'll will just keep going. 270 degree F seems quite hot to me. I'm flat out getting mine above 100 degree C (i'll let you convert that as i don't have the time to look for the exact conversion)

thats 212 degrees f

i took everything on the car apart today and found that the throttle was not fully opening. could it be that the engine was stuck in the mid range and when it needed the torque to drive or accelerate harder it would just stall because it wasnt getting enough fuel to generate the torque?

I'ld say that the tunning was out 'cause you are getting to 270 with out the use of full throttle. What i'ld personally do in that situation is set all the needle back to factory and start again.

how far was the throttle opening?

When i had the msn set wrong and was having problems trying to get it tuned right what it was doing was comming out of corner fine then at about mid revs it was bogging as if it was rich then it would finally get going again. I stuffed around for ages trying to get it going right and found that there was a real fine line between it going alright and it just getting to hot. I've had to of these motors and never had them hotter then about 230 except when the msn was wrong. the first one i had said that the msn should be one turn in from flush (and i had my problems when i set it flush after cleaning the carby) and the new one says flush with the case. I've always found this motor runs better when the msn is between a 1/4 and 1/2 a turn in from flush and the other needle tuned to suit.

but once again i'ld set all needles back to factory and go from there.

if u richen the LSN make sure u adjust the engine to idle a bit higher. If the temp is 270F and ur carb was only open 3/4> then ur LSN is probably to lean or the plug isn't good. Use the P3 as it is a very good overall plug for the V-spec. Make sure u are running good fuel. I have found HPI powerfuel to run extremly hot. I now drive all my engines on Sidewinder fuel. The performace increased and the temperature decreased. If non of these things solve the problem u may have an airleak.