72 jackpiner

[johnnysurf1]

i finished the ama viewfinders grand prix with a broken piston,cracked cyl. on it's last race .it sat untill last month when i found someone to resleeve it.now it's almost ready.question is i've taken the 30 mm  amal off and replaced it with a mikuni vm 26 main jet 190.has anyone raced with this carb? or is the amal a better race carb. i race so cal dist. 37 desert,but will enter only the grand prix courses with it now. thanks

[Dwight Rudder]

Johnny, That is too small a carb for that engine. You want a 30mm or 32mm carb. What you have is a 26mm which would be fine for a 100 or maybe a 125.
IMO,
Dwight

[johnnysurf1]

thanks dwight,thats what i thought,i can't really get it dialed in.i took the motor out yesterday,it was jammed in gear,it's freed up now,i'll put it back in and put my amal back on.i took yhe amal off because after about 15 minutes of hard racing it would not throttle. wide open throttle it would just blubber,holding it open it would eventually clean out and run good,losing to many positions in process.

[socalmx]

Get a nice 32mm Mikuni and get rid of the sloppy/drooling Amal and you will be happy. I also race D37 desert and actually raced a couple of the 100's MC races about 10 years ago on a DKW 100. Fun but I think I will stick with my WR250F

[johnnysurf1]

it's in the washboard whoops section that takes it's toll on the dual rear shock bikes. still it's  a challenge . i race a maico 400,and a husky 450 also,i've seen some nice dkw's there at adelanto. thanks for the input.

[socalmx]

The nice DKWs at Adelanto belong to my brother and friend. I use to race there on my Penton but in 2006 I almost got jumped on by a dual sport bike. Seems that the Desert Vipers felt that it is ok to mix modern and vintage bikes on the track at the same time. To me, this was not a good mix. The real fun race was the Elsinore Grand Prix but that is not going to be the same since they no longer will be racing in town. Bummer all the way around.

[johnnysurf1]

was your penton the 400 mint?

[VICTOR MONZ]

Johnny.

I raced a Jackpiner in the Elsinore GP a few years back and I had a 30 mm Bing with the air/choke adjuster on the handlebar control...I believe it allows you to cut the air down on straight WFO runs, hopefully lubricating your piston/crank a tad when wide open.
 
Correct if I'm wrong gentlemen, please.

I have the set-up still and it could be available, after some digging in the bins.  I am in Hemet,CA...close by.

Oh, I am still a Bing fan.....so far.  I think they are faster, just a little temperamental (like me)[}:)].

Good day to you all....So. Cal is 75 and sunny....I sure miss Amherst//Lorain area !

Victor

[johnnysurf1]

victor,sounds like the way to go,on the wide open dry lake sections i would kill the motor a few times to try to "oil it up",my jackpiner has a 30 mm amal. i just bought a 32 mm mikuni to put on it. seems like your handlebar setup would be good to have,my maico has a bing on it,see if you can find it

[socalmx]

quote:Originally posted by johnnysurf1

was your penton the 400 mint?

Too big of a monster for me. I raced a Six Day 125.

[socalmx]

In the day, I don't remember ever having to play games riding wide open in the desert. On a trailbike, that was the only option you had.

[VICTOR MONZ]

Johnny.

I will search tomorrow a.m. and see what I have.  I believe it will need the magura choke control on the handlebar and the Bing...30mm with the air slide this is the right combination....the control cable always seemed to hard to find, I may have that too.

I will check it out and report back to you.  The air slide allows you to lean or rich up the air/fuel mixture at your finger tip.

I also have a nice Jackpiner head if you might need one.

I'll find what I have then we'll chat on personal e-mails.

Thanks

Victor

[johnnysurf1]

might need that head, i blew the spark plug out of mine on a sat. before a desert race,i took it to a used dirt bike shop in phelen,i think, they repaired it and got me going.they did it dirt cheap too.