R1 Carbs (lots of pics)

[72240z]

Its safe to try because you can just solder the hole closed and drill it again to a smaller size if you need to. Poor mans jet trickery lol.

[slingshot532]

Dude! Do not atempt drilling your pilots (ask me how I know). The opening is way to small. I recomend running 17.5 pilots. I got mine from these guys.

 

http://www.pjmotorsports.com/mikuni-jets.html

 

Also at least get a regular AF meter with standard O2 sensor. lets you know you are in the ball park, and what you need to work on. And it is eazy to glance at while driving.

 

My car made the pops when running lean because of an air leak.

 

I am running #17.5 pilots 2 turns out and 2.5mm mains, and it runs great but slightly rich. I want to get smaller mains like 2.25mm but I don't want to deal with the cracked carb body again. I will eventualy. With the stock #15 pilots it ran lean at idle.

 

Good luck!

 

My car dose this wierd thing. If I run at full throttle through a couple gears then get off and back on the gas it goes way lean and feels like its going to die. I am thinking it may have something to do with the floats, I never tightened up the clips and I think the float levels drop to low. Dose this sound right?

 

As far as filters go, nothing yet. It sounds like this thread in my head, I have many different ideas. I am leaning twords custom short stacks like Rice's but with the flared section midway down the stack with room on the end to attach pod filters. To do this I will need to cut the hood because of the angle and length of my runners. I am not sure if I want to cut the hood. It might look sweet with the filters sticking out through the hood but it may not. Or I could get a scoop. Indecision. I even thought about getting a 240z air box and making that fit. I do want filters of some sort.

 

As for expensive filters, the main idea for this build, for me, was afordable, do it myself, and EZ. If I wanted Gucci stuff I would have gone that route.

[72240z]

drilling is common practice in grassroots tuning. Obviously though one has to get the correct bits lol.

[DADZSUN]

Dude! Do not atempt drilling your pilots (ask me how I know). The opening is way to small. I recomend running 17.5 pilots. I got mine from these guys.

 

http://www.pjmotorsp...ikuni-jets.html

 

Also at least get a regular AF meter with standard O2 sensor. lets you know you are in the ball park, and what you need to work on. And it is eazy to glance at while driving.

 

My car made the pops when running lean because of an air leak.

 

I am running #17.5 pilots 2 turns out and 2.5mm mains, and it runs great but slightly rich. I want to get smaller mains like 2.25mm but I don't want to deal with the cracked carb body again. I will eventualy. With the stock #15 pilots it ran lean at idle.

 

Good info, thanks!

 

Just to confirm, you're running a stock KA24e? What about the exhaust?

[VintageRice]

Dude! Do not atempt drilling your pilots (ask me how I know). The opening is way to small. I recomend running 17.5 pilots. I got mine from these guys.

 

http://www.pjmotorsports.com/mikuni-jets.html

 

Also at least get a regular AF meter with standard O2 sensor. lets you know you are in the ball park, and what you need to work on. And it is eazy to glance at while driving.

 

My car made the pops when running lean because of an air leak.

 

I am running #17.5 pilots 2 turns out and 2.5mm mains, and it runs great but slightly rich. I want to get smaller mains like 2.25mm but I don't want to deal with the cracked carb body again. I will eventualy. With the stock #15 pilots it ran lean at idle.

 

Good luck!

 

My car dose this wierd thing. If I run at full throttle through a couple gears then get off and back on the gas it goes way lean and feels like its going to die. I am thinking it may have something to do with the floats, I never tightened up the clips and I think the float levels drop to low. Dose this sound right?

 

As far as filters go, nothing yet. It sounds like this thread in my head, I have many different ideas. I am leaning twords custom short stacks like Rice's but with the flared section midway down the stack with room on the end to attach pod filters. To do this I will need to cut the hood because of the angle and length of my runners. I am not sure if I want to cut the hood. It might look sweet with the filters sticking out through the hood but it may not. Or I could get a scoop. Indecision. I even thought about getting a 240z air box and making that fit. I do want filters of some sort.

 

As for expensive filters, the main idea for this build, for me, was afordable, do it myself, and EZ. If I wanted Gucci stuff I would have gone that route.

 

 

 

Dude, thank you so much for chiming in!! Excellent info. Guess I'm ordering some pilots!!

 

Since we are the only two R1/ ka24e owners I know of any help is awesome!! That's one bad thing about being unique. Hard to get feedback and info. Thanks again bro!!

[VintageRice]

Cool, ok, the jets are $8 each from that site. Nice cause it gives you the part number for the R1 jet in particular. Then wifey found them on ebay(yeah, my wife was hunting for datto parts......its a sweet thing) for about $5 each.

 

But then I found this. Yeah baby, just gotta get a micro drill bit set and I'm set!! (pun intended)

 

http://www.cmlsupply...CFQ5ThwodhisAIQ

 

Call me Mr. Frugal

[72240z]

Ya man it adds up lol, a lot of us triple dcoe guys just drill them. Again too if you find you have gone to rich or want to try and lean it back you can just solder and re-drill the holes. easy peasy

[VintageRice]

So.....math time.......Mikuni jets are rated in numerical sizes, for example a 200 main jet has a 2.00mm bore.

 

The pilot suggested by slingshot was a 17.5 That means I would need to drill it out to .175mm Thats frackin tiny.

 

Bought harbor freights smallest size set today. Measured in wire guage sizes. The smallest being a #60. Which is .040 inch.....which comes out to 1.016mm and a 101.6 jet size to be exact.

 

 

So the SMALLEST drill bit I can get from a normal manufacturer of tools, is still about TEN TIMES too big for the jet sizing I need. Thats hard to imagine.

 

I'm going to pull my carbs, remove the jet, and see how amazingly small this hole is! I'm flabbergasted that it could be that small but the math doesnt lie.

 

 

Heres the set I got today for $20 at harbor freight. Figured its good to have on hand anyway.

 

[VintageRice]

#80.......the smallest I can find. crazy.

 

[Drummerboy4as]

is there a reason you don't want to just buy them?

http://www.ebay.com/itm/Mikuni-Pilot-Jet-Low-Speed-RS-HS-HSR-VM28-486-17-5-/170711575765?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item27bf33ecd5#ht_2289wt_908

[VintageRice]

Usefull tool for Jet drilling.

 

[VintageRice]

is there a reason you don't want to just buy them?

http://www.ebay.com/...5#ht_2289wt_908

 

Couple reasons. If I could have got a proper bit today, I could have done it and drove my car today......not in a week(shipping)

 

And with a bit set I can always go bigger. And could use the set for mains later too if I need to bump up jetting. Plus, if I'm spending monies might as well get a bit set too.

 

 

 

 

 

 

This is only $7.25 shipped........

http://www.ebay.com/itm/New-21pc-Micro-Drill-Bit-Set-Index-61-80-w-Swivel-Head-Pin-Vise-US-FREE-SHIPPER-/271028826356?pt=LH_DefaultDomain_0&hash=item3f1a93b0f4#ht_793wt_1171

And I consider this a whole set of jets........In theory. :D

[72240z]

Where are you checking for bits that you cant find them? Look for jewelers or watchmakers bits.

http://www.cmlsupply...l<br /><br />

 

choices

http://www.cmlsupply...<br /><br />

There are a ton if you google for jewelers/watchmaker stuff. I got my set that way.

[VintageRice]

Yeah, I can find them online but not in local stores.

 

 

BTW, just looked closer at the conversion chart...........smallest bit is a #80........thats .343 mm..............still too big....................dangit.

 

 

 

Pulled the carbs off, yeah, its soooooooooooooo small. How that can run a motor is beyond me! :blink:

[72240z]

Ah ya I have no idea where in the real world to get something like that :-/

 

Ya they are tiny lol.

[HudsonMC]

Maybe you'll just have to spring for the actual jets. Kind of stinks. Fortunately, the pilot jets aren't something you'll have to swap out regularly for tuning, as they're sort of "upstream" of the idle mixture screws. The pilot jets just change the range of adjustment that your idle mixture screws provide. You set the idle mixture with the screws.

[VintageRice]

Yeah, I know. Ordered the 17.5's off ebay last night. I hope they're right. I might still get a drill bit kit. Even drilled too big you'd think you could just open the screw like a 1/4 turn or something :)

 

Called around and HobbytownUSA sells the micro drill bit sets locally btw. I might go get one........not sure yet.

[DADZSUN]

Vintage: Given the size of the bits/hole, I would imagine it is VERY hard to drill perfectly straight down into the jet w/o some kind of press/machine. Even the slightest angle off could impact it's performance comparative to the other 3 jets.

[slingshot532]

The hole in the pilot is about the size of a hair, I have no idea how you could drill it to the proper size without the prorer setup. It's deep to. A bit that small would just snap. I actualy drilled mine with the smallest bit I could find. It was real hard to start, then started billowing smoke and smelling like kerosene. I had to order the new jets, wait a week with the car down, then install. Trust me you did the right thing by just buying them.

 

Side note, that hole is so small it should get clogged with gas sludge all the time, great reason for a good fule filter.

 

Progress - none.

 

Work - lots = more monies for Datsun!

 

Good luck!

[72240z]

Since there is already a pilot hole there to follow its actually hard NOT to drill it straight. You would snap the bit from forcing it sideways long before the hole went cocked. Its also so mall you can drill it by hand, nothing special required besides some fingers and knowledge lol. You guys make it sound like its rocket science....

 

If your jets are getting clogged by "gas sludge" all the time you got other problems that need to be addressed.

[VintageRice]

Since there is already a pilot hole there to follow its actually hard NOT to drill it straight. You would snap the bit from forcing it sideways long before the hole went cocked. Its also so mall you can drill it by hand, nothing special required besides some fingers and knowledge lol. You guys make it sound like its rocket science....

 

If your jets are getting clogged by "gas sludge" all the time you got other problems that need to be addressed.

 

Agreed.

[Cuts metal like mad]

You shouldn't have to do much if anything to the pilot circuit. These carbs react really fast, and come off the pilot at about 1200-1500 rpm. If it idles smooth at 3 turns out, leave it. Pop on decel could be a rich condition mixed with a leaky exhaust.

[Tristin]

Thinking about taking the plunge... Time to re-read from page 1.

[VintageRice]

Ok, got new jets in. Went from the #15's to the #17.5 Thats one step up.

 

Put'r at 3 turns out. Test drive. Upon decl, it takes longer to start popping, more time, and isn't quite as bad. On idle its less poppy, but you still hear a bubbly flub flub pop pop flub(like my sound effects?)

 

So, I went and got a micro drill bit set at hobbytownusa for $19.95

 

Now that I have a spare set of pilots I'm gunna drill the old ones out a few steps up. Like maybe #30ish We'll see where that takes me. Sure wish I was doing this with a wideband.........

[72240z]

Buy one on ebay just to tune and sell it after