fresh port and stuff now wont run

[teamcasslake]

just got my motor back from the builder and put it all together and it wont run it only farted a few times and thats about it. pulled the plugs kinda wet from prime cranked it over with the plugs out it has great spark, and the air that is being pushed out is hot from the cylinders so it was firing something.

list of motor mods pre-Porting is - msd enhancer, air filters, limited b-pipe.

post porting mods are msd enhancer, filters, limited b-pipe, ada head 37cc, case porting, cylinder porting, chokes removed(primer installed), little bit of stator timing advance, i think that is it but i might have missed something.


i think it could be timed off(firing on the wrong stroke),

i had to clean the carbs cause needle and seat were stuck.

does anybody have some kind of idea about what to do?

 

[yamahammer]

compression might be too low after porting and make it run crappy or not at all- check compression if its way low like 100 psi or so get some new domes and try again- i dont know about ignition timing i always run mine stock and its a hammer- i dont get why people mess with the timing if you cant throttle engine wide open for any amount of time afterwards- anyways good luck hope this helps

 

[Mouthfulloflake]

it only has 2 strokes, and if the flywheel and its locating KEY are installed correctly, its pretty hard for it to be very far out of time.

How far did you rotate the stator when you advanced the timing?

I run all of mine advanced, and can hold the throttle open, its just one part of the puzzle in the entire setup.

just got my motor back from the builder and put it all together and it wont run it only farted a few times and thats about it. pulled the plugs kinda wet from prime cranked it over with the plugs out it has great spark, and the air that is being pushed out is hot from the cylinders so it was firing something.

list of motor mods pre-Porting is - msd enhancer, air filters, limited b-pipe.

post porting mods are msd enhancer, filters, limited b-pipe, ada head 37cc, case porting, cylinder porting, chokes removed(primer installed), little bit of stator timing advance, i think that is it but i might have missed something.


i think it could be timed off(firing on the wrong stroke),

i had to clean the carbs cause needle and seat were stuck.

does anybody have some kind of idea about what to do?

 

[tipafew]

I would think that you possibly have a loose wire on your stator or an MSD that puked. They can both have this symptom.

 

[Frosty]

I would think that you possibly have a loose wire on your stator or an MSD that puked. They can both have this symptom.

i've seen that happen... check the two wires where they connect to the bottom most coil on the stator.

 

[Big Kahuna]

did you reverse the fuel lines? Seen that happen, done it myself many times when in a hurry. also, check the white wires leading to your enhancer, if they are switched it will want to fire right when you let off the start button.

 

[jet pirate]

be careful i would leave timing marks at stock !! with porting and other mods you are running risk of detonation !! chances of detonation are higher when you advance the timing i would recomend race fuel if you leave timing advanced !!

 

[teamcasslake]

when i first put it together my needle and seat were stuck open in the front carb so i rebuilt the carb and still not running. i took the ebox apart but didnt unplug anywires but the pink one for the temp sensor in the head(ada head dont need it) i ran the msd last year so i dont think its that. before we took the stator off we put a scratched a mark in it so we advanced it maybe 4* past that mark. the lines arent reversed cause i can see it pumping fuel and with the stock SBN 38's it is kinda hard to swap the lines around.

when i had the box apart it looked like one of the mounting ears on the msd were cracked but idk. i still have great blue spark that will jump a 1/4 inch

and when it starts it almost feels like it has 2 much compression and will like stop cranking over for a a stroke and start again like it has to much compression

and im running 37cc domes on 93 octane so im not to worried about detonation

 

[jet pirate]

when i first put it together my needle and seat were stuck open in the front carb so i rebuilt the carb and still not running. i took the ebox apart but didnt unplug anywires but the pink one for the temp sensor in the head(ada head dont need it) i ran the msd last year so i dont think its that. before we took the stator off we put a scratched a mark in it so we advanced it maybe 4* past that mark. the lines arent reversed cause i can see it pumping fuel and with the stock SBN 38's it is kinda hard to swap the lines around.

when i had the box apart it looked like one of the mounting ears on the msd were cracked but idk. i still have great blue spark that will jump a 1/4 inch

and when it starts it almost feels like it has 2 much compression and will like stop cranking over for a a stroke and start again like it has to much compression

and im running 37cc domes on 93 octane so im not to worried about detonation

cranking compression meens nothing its your compression ratio !!! with ported and bored motors that ratio goes up !! i have a 767 ported motor with 180 compression but i have to run a higher octane because when all is calculated i'm running 13.5 to 1 compression. do the math whoever built the motor should know this information. i rec no advance !!!!!!!!!!!

 

[jet pirate]

if your motor was decked you will have low compression due to spacer and added combustion chamber volume wich will require smaller domes !!

 

[teamcasslake]

im sry but if u deck a cylinder ur REMOVING material so the compression will go up and to get it back to the same compression as it was pre decking u would have to go to bigger domes or thicker base gasket.

 

[skinnyman]

Call your builder and get your specs and talk about timing with a enhancer

They have some advance built in check the MSD site

 

[jacob06]

make sure you got a fresh charged battery- hit the starter- if its slow to crank still - you got a bad battery or starter and they dont help

make sure you have a spark- stick your finger in it if you have to - when msd's mess up you either get nothing or the revlimiter manages to get stuck real low magicly all by itself.

i'd imagine you'd have to move your stator all the way 1 way or the other to get it to not run at all. i'd guese that it would still probably crank up and run then anyway. but just run like crap when you put it in the water.

check the compression

make sure your getting fuel - pour a shot glassfull of premix straight in each carb

hit the starter-

if it cranks up and runs when you pour gas in the carbs and then quits after a few seconds, your carbs arent sucking fuel. - i bet this is your problem

you can also put your hand completely over the top of the carbs and crank it over to choke it and see fuel running down the inside when the carbs are working.and if they are bone dry...

you need fuel ,spark ,and compression for the motor to run. if you got all 3 of those, then somethings probably not sealing up (cases, intake mani, base gasket)- so do a leakdown test -

if all that checks out, send it back to the builder.

just my .02

 

[grahammy]

If you've got a spark, is it single channel or dual channel ignition... are the plug caps the on the right cylinder otherwise the spark will firing on the wrong cylinder.

If not, plugs are wet so you've got some fuel, are the reeds ok, maybe forgotten, broken or very badly seated?

 

[teamcasslake]

it sucks fuel just fine, it has great spark, and my compression test is at my shop cant get it tell monday, but with ur thumb over the hole it fells good(i know bad way to do it but it kinda works) i think my stator plate is just advanced to far and it is firing to soon. my battery is good, if it runs down i out it on the charger and start it that way, idk but im going to go to the builders today and have him dick with it cause im just pissed off that i cant ride.

the ignition is a enhancer and i ran it all last yr. the reeds are carbon tech and i was there when he put those in, he had a set of v-force delta 3's there and u could see light the the pedals and the cages(not good) and mine u couldnt see onr bit of light through any part.