R1 Carbs (lots of pics)

[Stupid_fast]

So I put a larger 190 main jet ...

 

Now its bogging and pinging from WOT until about 3500rpm ... Less pinging with the smaller jet!

after 3500 it pulls all the way to 6000 nicely.  Seems less responsive with the 190 mains. 

 

Any tips? I'm going back to the 180 and then mess with the pilot system.

 

Needles are one notch rich.   Also I noticed my needles have 6 clip positions.  maybe aftermarket ??

[spudly13]

well, based off my experiences, 190 is huge... i was all the way down at 160 with my l20 and my wideband was telling me that was money

 

With the 180s back in try dropping the needles and see what that does.

[Stupid_fast]

well, based off my experiences, 190 is huge... i was all the way down at 160 with my l20 and my wideband was telling me that was money

 

With the 180s back in try dropping the needles and see what that does.

 

Wow really?  That sucks cause I had a set of weber 180's and I just drilled out my 138's to 190 thinking I'd never need anything smaller than 180...

I'll run to VW shop tomorrow and buy some jets to drill out.  160's on an L20 ?? this thread says 160's on an L16..

 

I'm gonna go pick up some fresh plugs tomorrow and see if I can get it tuned up.   

 

Thanks for the tip. 

[slingshot532]

Good job Stupid!! Looks and sounds great!

 

You are going through all the R1 growing pains. Check all your conections for air leaks: carb to intake, intake to head, This can cause strange lean conditions, maybe lean in one cylender. My rubber couplings kept coming loose causing poping. An A/F guage will also help. my o-rings leaked for a day or two also.I think if you soak the o-rings in gas while you have them out they should seal fine. Thanks for adding to the knowlege.

[Zendar]

Stupid_fast, how did you mount the filter backplate to the carbs? could you take some pictures?

[Stupid_fast]

@slingshot, thanks .. The carbs actually run great my issues seem to be unrelated to air/fuel tuning ...

 

 

@Zendar,  This setup is from Bogg Bros UK ... they sell the filter already modified.

Stock R1 airbox rubbers I think. 

 

[Zendar]

Thanks for the pics, I have the same kit, gotta get those rubbers to mount it then :)

[chiwag]

Hi, I have time I want to do this with my motor. I'll do it in a j15, I know I know it is not indicated for this engine but I would leave it as it is the original that brings my wagon and I have not seen much on this engine I think that would be original. I offer a few carbs r6, but not if they are or should some of r1? this week would do this and I'll post some pictures so you can see how it turned the job.

[Stupid_fast]

I love this carb setup so far.  Even not perfectly dialed in its very smooth below 2000rpm drive able around town, throttle response and power at the top are great too.

 

Had my datsun mechanic friend ride in it, it is not pinging.  He said to pull it up to 7k, It pulls all the way to 7100 ... power drops off about 6800rpm with this cam. 

 

I do have to get the low end perfect with the wideband, but so far its running great.  180 main jets, 17.5 pilots, needles set half way.  Friend set up the idle mix I still gotta count the turns and figure out where he set it.

 

It still pops on decel around 3000rpm, but its a lot less than when I first got it going. 

 

Here's what it sounds like on a cammed L20b.

 

http://www.youtube.com/watch?v=rrMIsK7S9EE&feature=youtu.be

 

This road is completely uphill ... just sayin.

[Stoffregen Motorsports]

That sounds really sweet. I wasn't sold on the idea before, but you guys seem to have it figured out.

 

BTW- is that house that's shaped like a saxaphone still up there on the hill? I have fond memories of the Berkeley hills...

[VintageRice]

1. Your car rattles like crazy!  Does mine sound that bad on video?!   :rofl:

 

2. Your car RIPS !   :thumbup:

 

3. Those wipers would drive me nuts in the middle of the windshield...............Push'm down for goodness sakes ! !   :P 

[Stupid_fast]

That sounds really sweet. I wasn't sold on the idea before, but you guys seem to have it figured out.

 

BTW- is that house that's shaped like a saxaphone still up there on the hill? I have fond memories of the Berkeley hills...

Saxaphone house ? I've never seen it personally.  I have not really gone exploring in those roads, I usually stick to the more secluded back roads.

 

Aye, the bike carbs seem to be the most smooth street carb option.  I'm really liking them.

 

1. Your car rattles like crazy!  Does mine sound that bad on video?!   :rofl:

 

2. Your car RIPS !   :thumbup:

 

3. Those wipers would drive me nuts in the middle of the windshield...............Push'm down for goodness sakes ! !   :P 

Rattles? yeah... 200lb front springs stiff shocks, stiff modded leafs, stiff rear shocks, some solid TC rods, ect .. makes it rattle ! 

My window weather stripping needs work, and a lot of other things.  I just been working on getting the motor and suspension sorted(safe and drivable) before worrying about any of that.  Its actually not horribly scary to drive anymore ! It does not wander all over the road, ect. 

Also those roads are pretty bumpy ... on a smooth road its not nearly as bad.  And there is a zipper on the seat where the phone is mounted.  Yes, I recorded that with my cell phone with a fish-eye lens.

 

Aye, its quite quick !  I am going to put a 4.375 diff in it soon as well, should be even faster.

Its great putting it in 3rd and 4th and still pulling strong !  A lot more punch than the DGV.

I never went over 5900rpm in that video ! Most of it was pulling out of corners around 3000rpm. 

 

 

I adjusted the wipers like that to get the maximum amount of travel across the window ... Its practical. :P

[PHANTOMa]

Here's my tiny contribution......carbs came with the throttle plate.....adjuster cable thing.....anyways I chopped it down so I don't have a loose cable flying around under the carbs and welded it back to make it a lot cleaner

[VintageRice]

Good idea, I zip tied mine to battery tray, because.......ka. It hangs right over the alternator.  Yeah, it welded itself to the HOT terminal one day.......just for a second.....but still, gas plus sparks = bad day.

 

I may have to chop mine like that.  

[Stupid_fast]

So I got my innovate LC-1 hooked up...

 

its running about 12.0 AFR at idle ... WOT up to 2200rpm 9.8 - 10.5(Losing power, cant WOT uphill have to half throttle to get anywhere...), 2500rpm 11.5, 3000rpm 12, 4000rpm 12.5, 5000rpm 13, 6000rpm around 13.5,  Saw 13.7 as I was pulling past 6100 WOT.

 

this is with a 17.5 pilot and 180 mains, the needles are set one step lean from mid point.

 

So it seems the larger pilot removed the popping out carb at lower RPM, but now its causing it to be really rich ??

 

Cruising, below 2500rpm is around 12:1 when I'm barely on throttle/holding speed, above 2500-4000 its around 13-14 AFR ...  Strange thing, when I'm cruising in 5th around 3000rpm (72mph) it runs about 13.5-14, it will pop out of the carb with slight throttle adjustments.  Or if I get on the throttle about 10% open, off throttle, 10% throttle it will go to 15 AFR and pop out the carb.  

 

It pops out the tailpipe off throttle around 3300-2700rpm, but its only about 14.5-15 AFR.

Its drivable and makes good power, but the popping in 5th under light throttle/light load makes it undrivable for highway.  I was going over a bridge sunday with some heavy wind resistance, and it was making good torque but kept popping out the carb.

 

Going to go back through the thread for tuning info, just wondering if anyone has some tips for me !! 

[spudly13]

from everything I've been told, popping out the carbs is either one a lean condition, which it doesn't sound like it is, or two the carbs are not balanced

[Stupid_fast]

The carbs are balanced ... I had my mechanic check my work too.

 

From everything I'm reading of bike carb tuning, everything scales from the main jet.  I'm going to return everything to baseline, and go up on the mains and see if I can get the AFR better at the top (4500-6500 ).

[PHANTOMa]

My $10 velocity stacks. Beats $250 off eBay!!Just rough start. But will be epic.

Hey man those stacks came out sweet......you think any muffler shop can do that or should I roll by the one you went to?

[spudly13]

Hey man those stacks came out sweet......you think any muffler shop can do that or should I roll by the one you went to?

 

Any exhaust shop "should" be able to do this for you. Just be clear about what your asking for.

[spudly13]

The carbs are balanced ... I had my mechanic check my work too.

 

 

From everything I'm reading of bike carb tuning, everything scales from the main jet.  I'm going to return everything to baseline, and go up on the mains and see if I can get the AFR better at the top (4500-6500 ).

 

:confused:  Why would you go up on the mains? you want it richer then 12.5-13.7 afrs?

[Stupid_fast]

:confused:  Why would you go up on the mains? you want it richer then 12.5-13.7 afrs?

 

13.7 is a bit lean for WOT. At cruise I would want around 14.0:1 from what I've been reading about carburetor AFR tuning !

[72240z]

Stoichiometric air fuel ratio is 14.7. You want to be slightly over during wot because engines make more power slightly rich. During cruising you want to be slightly below or at it for best mpg. 

going one size up or not on the mains depends on where you are on adjustment. Sounds like you could go one step up though. 

[VintageRice]

Hey man those stacks came out sweet......you think any muffler shop can do that or should I roll by the one you went to?

 

Yeah, the guy I got them from is really old and had a hard time understanding what I wanted.  It's hard for a exhaust guy who makes something you never see every day to understand I wanted them all four EXACTLY the same, and to look good.  It's hard too I'm sure using a huge hydraulic machine to get to millimeters in accuracy lol.

 

But after a few tries he got it. Was nice cause I could stand there and say, yeah THATS what I'm looking for........now do THAT 3 more times.   :D

[PHANTOMa]

Haha fersure......must've been hell getting them into such a tight tolerance........I'll see what I can come up with this week for'em.....just pulled the fwd SR manifold from storage and I'm gonna get to work on chopping it and getting some runners welded on sometime this week too

[dangero]

hey guys,

 

This is my first post here and I am having some issues with R1 carbs. I have read all 50 pages and I am not quite there yet!!!

 

I have been building a PA10 datsun (stanza) in australia I bought the shell complete with roll cage rally prepped interior, suspension and tyres. but without and engine or gearbox.

 

I did a full rebuild on an L18 with the following specs:

 

l18 W series siamese block bored and honed 1.75mm oversize

L28 flat top pistons .75 oversize

A87 head with ports cleaned up and mild reshaping, polishing

Wade 733A cam (not to wild)

CR 11.2:1 roughly

 

I have just finished the motor a few weeks ago and had it running perfectly on a pair of SU 1.75's as soon as I fitted the mikuni's I have not been able to get it to start.

 

hers are some photos of my datto

 

 

 

 

 

here's how I have the carbs set up

 

custom manifold, 99% sure its sealed and not leaking air

fuel is being fed to the under side of the carbs on the second carb from the front

main jets have been drilled to 1.6mm (can drill them bigger but wanted to start off at the smallest size)

mixture screws 3.75 turns out

air mixture hole on the throttle side blocked (the one that feeds airbox pressure to the main jet)

needle set at the second richest position (circlip second bottom notch)

stock l series fuel pump

 

 

the carbs have been pulled down and given a good clean, all the jets are clean, I have hokked up throttle and choke abut no matter what I do I get no go. I am getting spark, I pulled out a plug and turned the motor over and saw spark when the plug was grounded. It appears that I am getting SOME fuel, I pulled the plugs burnt off all the carbon, replaced them turned the motor over, removed a plug and flicked a lighter over it and the small amount of fuel on it ignighted. the plugs were REALLY fouled but I am not sure when it happned (before or after fitting the new carbs)

 

another thing I have noticed is my needles are hollow with 2 rows of little holes in either side, they are not the tapered needles pictured everyone appears to have. The main jets laso had 135 stamped in them and I am wondering if these are the issues.

 

I have also noticed quite a lot of pressure building in my supply line, when i remove it about 10ml of fuel goes everywhere. is it possible to over fuel with a stock pump? the float bowls are full and the carbs are not overflowing or leaking at all.

 

Hoping someone can shed some light on the needles/jets.

 

I am so close I can taste it!!! I cant wait to see how the bike carbs go, it was pretty awesome with the SU's