Well... i just did something bad....

JoeRainville · Post by **JoeRainville** » Thu Feb 28, 2008 9:51 am

TakeItToTheLimit wrote: It was kinda like the 830 Two-Cylinder Tractor...if you wanted more power...something had to change.

Rich,

That a good analogy, and kind of funny!

JDX-8. If you bolt a 76-78 carb to your JDX-8, the carbs will be pointing downward. The motor on the LF leans forward to lower the CG, while the JDX-8 motor is 'straight up'. You will need to modify the manifold to make it work correctly.

However, as Rich pointed out, dual 34mm Mikunis and a 75 JDX-8 pipe will get you into that "Ludicris Speed" range for a sled with a 28" ski stance...

-Rainville

JDT · Post by **JDT** » Thu Feb 28, 2008 12:06 pm

Mikuni's do not have to be perfectly vertical to work.

They run just fine at an angle.

Liquifire 4/6 · Post by **Liquifire 4/6** » Thu Feb 28, 2008 1:57 pm

JDT wrote: Mikuni's do not have to be perfectly vertical to work.

They run just fine at an angle.

While the Miks will work ok at a reasonable angle, they definately will not work well beyond a certain point. I'm not sure what that point is exactly, but I'd guess about 4-7 degrees. I think you can compensate a little by adjusting the float to sit level.....but there's definately a limit as to how far you can stray from horizontal. I put a Mikuni on an old AC Cheetah once. The engine in that sled sat at quite an angle and it simply wouldn't work without modifying the intake. I did so by using an angled adapter between the carb and the original manifold. This lengthened the intake tract considerably and was not a good solution as it seemed to hinder the high end throttle response and power. However, it gave it incredible low end power. And as the owner was an ice fisherman, he was happy with it because he did lots of low speed running pulling his fish shack around. Some time later I read that longer intakes will result in better low speed running but with an opposite effect on high end. Can anybody explain why?

440 invader · Post by **440 invader** » Thu Feb 28, 2008 2:38 pm

I don't think the angle is far enough off to be a problem, your float should take up the minor angle,sort of like parking on a hill or something. I don't know if anyone saw the Merc 440 S/R at Waconia but he has the same KEC 440/22 motor and he had dual Mikunis' on it, looked like 34's,And he doesn't have any problems. I don't think the merc would be any competition for a jdx,without the pipe,and a heavier weight,but it was still cool to see.

JDX-8 · Post by **JDX-8** » Thu Feb 28, 2008 8:37 pm

Nice!... i have a band saw... and a welder.. i can do alum.. but i have a friend that TIG welds a lot... and i mean a lot... if you all think it will be a problem.. i will take the angle right off of it... trim a little fat from behind the flange and reweld it back on... with a nice polish to the inside!....

So i have heard some on this thread say, others are using duel 34mm and some have mentioned that the 38mm should be close to dead on... since the artic cat that i would be using these carbs from was a 600cc and had 3 carbs... and im running 440 with 2 of them.... any thoughts???? since i have a few of each to play with!... but i do not in any way want to keep all these carbs!... i need to unload them soon... so trial and error i would like to avoid.. but i can buy jets all day!.... and im 99% sure i have acess to a wideband O2 sensor setup... to check for lean-ness and all... at least for a day i can borrow it!

If anyone has a source for the pipes... please throw it up here!... or better yet.. PM me!

as for the 75jdx8 pipe.. it still exits the floor or the side?... guessing floor!

440 invader · Post by **440 invader** » Thu Feb 28, 2008 9:47 pm

The X8 pipe exits on the right (passenger) side ,out the bottom of the pan,just ahead of the speedo housing. I don't think you would have to cut and weld the intake either. They seem to be thick enough to machine a couple of degrees off of the carb mount flange with a milling machine. Like I said earlier I've seen them run as is with no problems.

kenwaters · Post by **kenwaters** » Thu Feb 28, 2008 10:55 pm

jdx-8

I did the dual Mikuni conversion on a cyclone. The jet needle and needle jet are correct, the most major issue is that instead of the 180 mains, you need to use 220 mains. In response to the post suggesting you could use the 38 mm miks, without putting an exhaust probe in the pipe, I wouldn't use jetting specs from a different case and displacement and different cooling system. The 34 mm Liquifire carbs are close, and if it weren't for a having a cheap and lazy brother in law, Joe Rainville would have a cyclone with a fresh motor and tuned carbs, but instead has a motor that needs a piston and some more carb tuning.

Hope this helps,

JDT · Post by **JDT** » Fri Feb 29, 2008 12:43 am

Hey Kelly, keep in mind the Cat triple is liquid.

Rules change when you have fan cooling.

JDX-8 · Post by **JDX-8** » Fri Feb 29, 2008 1:03 am

so you ARE telling me to stay with the 34mm carbs then?... just want to make sure i got ya on that one!!! As for the 34mm carbs that i bought.. i have no idea what is in them... bought them off ebay you know... so im unsure of what they came off of, and what parts are inside.... as for me running 34mm's.... what needle and jet shold i be hoping to find in mine?....

440 invader · Post by **440 invader** » Fri Feb 29, 2008 2:00 am

Usually jetting is different between your mag and pto cylinder,but I'm thinking a port engine like a Kawasaki Intuder, I'm not to sure if you'd run a fatter jet on the pto side, of a reed case motor,but still think that the farther side from the fan would be hotter. I guess try it but keep an eye on your plugs.

kenwaters · Post by **kenwaters** » Fri Feb 29, 2008 10:26 am

JD-X

Your 34 mm bodies are probably fine, by that I mean that since you are not going to be using a stock Deere airbox, you don't need to worry about the opening diameter on the bell mating up to the airbox boot. Just look up the carb specs for either setup in the FAQ section. One 34 mm mikuni would probably do you just fine for the trouble, and the Cyclone manifold wouldn't need altering to keep the carb somewhat level.

JDX-8 · Post by **JDX-8** » Fri Feb 29, 2008 3:10 pm

Well, got the liquidfire intake in the mail today!.... fits perfect...i see what you all are talking about now, with it being at aslight angle... like 3deg or so... if i remember correctly.... on my race bikes i used to have, they sat at much more of an angle (ZX-6R Kawasaki ninja's).... if i have a problem with them... i will machine the intake or the carb flange a bit... Found the choke, and throttle cables i needed in the Kirk cataloge! About $15 each.. not to bad!

the package i recieved in the mail today.. also had the reeds from that motor... and they look much nicer than mine... are there any differences in them?.. would it be okay to use the ones i got in the mail today... they look the same...????

River Rat · Post by **River Rat** » Fri Feb 29, 2008 4:01 pm

JDX-8.. I have the X8 tuner pipe if you decide to go that route.. (Might know I would have one eh DA?)

Frankie(Iowa)

JDX-8 · Post by **JDX-8** » Fri Feb 29, 2008 5:32 pm

PM sent!..... Just won the starting system from ebay.... $9.99!.. and $9 shipping~~!!!... that is all i needed for my starting system except for the battery box.... but if i get a tuned pipe from the 75' model... then i will not be able to mount the batter there right?.... so i would mount it in the center section where the old muffler was?.... have a good one guys!!!, Kelly

440 invader · Post by **440 invader** » Fri Feb 29, 2008 7:31 pm

Thats what I did,moved the mount for the wiring and the battery to the center of the sled,instead of mounting on the outside of the frame rails mount to the inside and you will be ok......just not as easy to get to the battery.