alky cub problem

[dajogejr]

NO offense Gray...but you pretty much thread jacked this guy's questions...and I'm rereading this whole thing realizing if I answer your question, I'm not answering his question... I got confused real quick as to what this thread was about....

[superfastyfz450driver]

thanks dajogejr, im going to be working on this banshee saturday and sunday again, the methanol is a brand new fresh 45 gallon drum that i order last week and only opened it up when i was finaly ready, the mikuni tmx carbs that i am running use 2 sliding floats that slide up and down on a rod in the float bowl and the guy who had them before remove 1 of the floats, i have the largest needle and seat set up in the carb as i can get a 3.5 i believe, now if i need a fuel pump i now i need to go to a smaller needle and seat but what size roughly

[superfastyfz450driver]

update, i found i was way to lean raised the needles and went to a .126 main here is some pictures of the plugs after a 300 foot full throttle run , no idling after, i am running pro race fuel's methanol mixed with klotz super techniplate mixed at 32:1

 

[dajogejr]

Looks a little rich...what size is your dump tube?

Be very careful..at .125 mains the threads are paper thin and can snap off...

[superfastyfz450driver]

i dont know what the dump tubes are actually i will go to the shop and pull a carb off and measure for a sec

but from what i understand if for example the dump tube measures .100 then there is no benefit from going to a main jet that is larger then the dump tube correct

[superfastyfz450driver]

the dump tubes are .115''

[dajogejr]

Exactly my point...essentially your mains are that big.

[J-Madd]

That plug looks like it has several runs on it or has been purged on. I can't read that at all. What are you seeing Dave? If that was a new plug and was that black I would call that lean; but since it is hopefully not a new plug, I don't know what to make of it.

[dajogejr]

I see the bottom of the plug base looks like carbon/oil caked on it...not burning from heat.

I don't like the EIX series plugs for gas or methanol, but that's just me....

[superfastyfz450driver]

these plugs havent been used for purging at all, and im going to have to agree with j madd about being a bit lean i opened up the dump tubes to .120'' and ran it and the mid range definatly richened up and you can tell it had to clear out a little bit before running clean on top but after that about 150 feet into the run it started to ping a little so i guess im going to have to go richer yet on top to keep it from blowing up

 

what size jetting are you guys normally running with the 421 cub engines, and you guys are all running at 32:1 oil mixture correct, what type of plugs to you recomend, i know i have my compression and squish a little on the loose side but i am running a 15 lap main event not just 300 feet runs thanks

jonathan jans

[superfastyfz450driver]

heres a new run on a set of brand new br9es plugs, no idling after the run and no purging neither

 

[dajogejr]

It normally take a couple runs to make any heat/marks on the plugs.

Judging by the second set, and taking into consideration it was only one run...I'll say it's one of two things.

It's lean and/or running out of fuel.

 

15 laps? Ok...I thought you were a drag racer only running 300 feet...

 

Give it more fuel...period. I run B9ES ( I Have resistors in my wires) at .018 to .020 and 28:1 on supertechniplate.

 

You're running methanol on a dirt track/circle bike? Not worth it in my opinion...do you have fuel pump, billet bowls, dual feed pingle? (Sorry if this was already covered...)

[superfastyfz450driver]

yes i have a dual feed high flow fuel valve, no fuel pump i will be upgrading to it if you believe it is necessary, what size of needle and seats will i need if i am running a fuel pump i know if the needle and seats are to big they will not close properly and the engine will flood itself out, and thats a no on the billet bowls unless i can find some one who makes them for a mikuni tmx carb, i appreciate your help so far however

[dajogejr]

Ok...help me out.

How do you run, how far, how long, etc.?

Keep in mind most of us that run alky run in a straight line for a determined length, 200, 300, 660 or 1320 feet in most cases.

 

You mentioned 15 laps...that's a different story...so fill us in please.

If you're on/off the throttle all the time that's one thing, if you're WOT all the time for a long period of time, that's another...

 

So we need more info.

[superfastyfz450driver]

Ok...help me out.

How do you run, how far, how long, etc.?

Keep in mind most of us that run alky run in a straight line for a determined length, 200, 300, 660 or 1320 feet in most cases.

 

You mentioned 15 laps...that's a different story...so fill us in please.

If you're on/off the throttle all the time that's one thing, if you're WOT all the time for a long period of time, that's another...

 

So we need more info.

ok 75 percent of the races are 8 laps which are 3/8ths mile the other 25 percent are 15 lap races on a not quite quarter mile track lap times are in the 18 seconds for the 3/8ths and i havent timed the 1/4 mile track the straights on the 3/8ths mile track are around 400 feet i estimate, and the 1/4 mile around 250 max so at full throttle i figured with the banshee i would be running for about 4-6 seconds then back off full brakes then full throttle again, if there is any other questions that you need to know just ask i will asnwer and do exactly as you say for jetting wise, or if its possible can you send your phone number in a pm and i can describe over the phone