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PostPosted: Mon Mar 17, 2008 4:41 am
by NIK
Can someone explain how the pcv works? i found a spare that works but it seems it lets air in not out how is this different from a air leak? Trying to understand how it works.

Also found this on porting.
http://www.sa-motorsports.com/diyport.aspx
Nik

PostPosted: Mon Mar 17, 2008 11:56 am
by Sarge
Simply put it maintains a vacuum in the crankcase by controlling engine vacuum via a spring and ball . If the windage or cylinder leakage is too high that valve prevent the built up pressure from getting into the intake and leaning the engine out. Under normal operation it pulls enough vacuum to keep a negative pressure in the crankcase . The "t" allows excess pressure to bypass and be routed into the air cleaner . Under high vacuum demands the spring is compressed and the valve closes , keeping all available vacuum in the intake where it's needed .
Sarge

PostPosted: Mon Mar 17, 2008 7:57 pm
by NIK
Great thanks had a play today and it seems to do that.
I alsosprayed alot of degreaser around to triple check for air leaks.I found one of the throttle shafts has a leak :cry:
So its off to get rebushed, I also saw the initial few teeth on the gears are worn so 1 side is SLIGHTLY slower for the first few teeth but the rest are 100%.
I have the 1piece adapter and i need to take more out for the 38 but its nearly into the adapter bolt hole. Would this be avoided with the 2 piece, what brand are they?
But I did get some 65 and 70 idles to try after its fixed.
Nik

PostPosted: Sun Mar 23, 2008 4:18 pm
by NIK
Has everyone given up on webers?
Found out the pos adapter redline sells is not actualy for weber to zuk swap its for asin?? to nissan swap, so that explains why the 38 wont seal properly!
Tried to order the 2 piece adapter went like this,
"im after 2 piece adapter redline part no 99004.333"
sorry thats an american part number explain what you want.
"two piece adapter for weber carb to suzuki manifold"
They dont sell such a thing
"well I saw it on there website!"
I have redline aust. on the phone and they say no
"but its on there website!!"
Oh redline america is seperate to redline aust you will have to order direct redline aust wont sell it.
:bad-words: wtff is that??
Any way been emailing sarge looks like as soon as I have the $$ my 38 and intake are off for a trip over seas.
Nik

PostPosted: Sun Mar 23, 2008 4:34 pm
by St Jimmy
No mate haven't given up
just pi##off as now mine
won't idle :armsup: :armsup:
So will be pulling it apart to
find out whats wrong
This time as I'm only getting
230klm to a tank :bad-words:
60 bucks for a rebuild kit to
make it worse so i will
persevere to i get my quad
carbs set up :roll: :roll:
catch you later
BONER

PostPosted: Sun Mar 23, 2008 4:55 pm
by NIK
Does it have any air leaks,check around the butterfly shafts.
I havnt used a 32/32 before but have you emailed him for jetting on it, at a guess id say the prim would be the same as a 32/36 on a 1300. Once jetted right I dont need the secondaries 95% of the time and it has more power than stock and reasonable fuel consumption.
Nik

PostPosted: Sun Mar 30, 2008 12:01 pm
by St Jimmy
Just went for a drive over the beach
and it started to hunt for fuel
OK on secondaries but stalls
on mains WTF so came home
and cleaned the jets still doing
The same thing :bad-words: :bad-words:
Any ideas as im really over
this carb. :bad-words:
BONER

PostPosted: Sun Mar 30, 2008 5:46 pm
by NIK
ok as in good or just ok on the secondaries?
When mine isnt getting fuel it shudders violently.
Anyway was ther anything in the mains or in the bowl? Ive had a few times were Id check the jets and they were fine but it was somthing in the bowl that would block the jet then fall out again so now I ran an extra filter just before the carb.
Did you check the idles as well?
If it has the fuel to run the secondaries it should run the primaries so somhow the fuel isnt getting to them. Has somthing made its way into the air/ etube well??
BTW have you checked with Sarge on the size throat of that carb? Is the primary the same as a 32/36?
Nik

PostPosted: Sun Mar 30, 2008 5:55 pm
by St Jimmy
NIK wrote:ok as in good or just ok on the secondaries?
When mine isnt getting fuel it shudders violently.
Anyway was ther anything in the mains or in the bowl? Ive had a few times were Id check the jets and they were fine but it was somthing in the bowl that would block the jet then fall out again so now I ran an extra filter just before the carb.
Did you check the idles as well?
If it has the fuel to run the secondaries it should run the primaries so somhow the fuel isnt getting to them. Has somthing made its way into the air/ etube well??
BTW have you checked with Sarge on the size throat of that carb? Is the primary the same as a 32/36?
Nik

1, Ok as long as you keep it above 4.500 grand good fun in traffic
2. Checked everything that could be checked
3, Been slack doing the SIDSandKIDS up and coming run
4. Will get s/n tomorrow and send to him
BONER ;)

PostPosted: Sat Apr 05, 2008 9:42 pm
by St Jimmy
:lol!: Will have to make a new manifold[sp] soon
as my quad carbs are on the way then the
Weber will be obsolete no more stalling going
up hills 4 mic's of a suzuki thousand . :turn-l:

:smilecolros:

PostPosted: Wed Jun 11, 2008 5:38 am
by NIK
Guess whats in the mail and shouldnt be far away....
Image

Fully rebuilt and "sargified" 38DGAS with ported and polished manifold :cool:
Should flow just under 400cfm (more than the stock head is capabale of)
so it will out perform the 32/36 and with the exrtra mods it will ran on angles!
Nik

PostPosted: Thu Jun 12, 2008 9:38 pm
by 86slowsierra
Nik. Just curious as to how much you are out of pocket after getting the 38 back from Sarge.

So how does the 38 perform?

PostPosted: Fri Jun 13, 2008 5:32 am
by NIK
Ive only ran the 38 once when it had a vacuum leak and it made the 32/36 look like a slug :cool:
As to price I was quoted $400 to rebuild my stock carb (thats why I went back to the 32/36) then I was quoted $400 to rebuild my 38.
Now this guy is great at his job but $400 to rebuild it to stock specs!!
Sarge on the other hand rebuild it, set float for off road, modded vent tube, used roller bearings and nylon seals for the butterflys, modded fuel bypass, supplied a 1 peice adapter (the ones we get here are crap, not meant for the application just bolt holes line up so redline aust. say good enough!) supplied fully ported and polished manifold INCLUDING frieght for the same price I could get it done stock localy.
I,ll let you know on the performance when it gets here mate just bought a dyno that Im keen to try out.
Nik

PostPosted: Fri Jun 13, 2008 7:39 pm
by built4thrashing
so what it cost ya?

PostPosted: Fri Jun 13, 2008 8:03 pm
by NIK
Sorry thought I put it in above, $400 including modded manifold, adapter, all sarges tricks and frieght back.
Got home at 5:10 today to find note from post office its here, now I have to wait till monday arvo!
Nik

PostPosted: Fri Jun 13, 2008 8:08 pm
by want33s
boner59 wrote::lol!: Will have to make a new manifold[sp] soon
as my quad carbs are on the way then the
Weber will be obsolete no more stalling going
up hills 4 mic's of a suzuki thousand . :turn-l:

:smilecolros:

Good luck with the bike carbs. :lol:

Fuel pressure is a problem with them as bikes are gravity feed so the needle/seat arrangement is quite weak. Usually the 4-5psi from a car pump is too much and if you regulate it down you don't get enough volume of fuel.

Maybe I'm just lucky but mine runs the standard Aisin carb and it doesn't stall even when standing on the rear bar!
Jas.

PostPosted: Fri Jun 13, 2008 8:13 pm
by alien
i dont think the issue with the aisin carb is its stalling - for me it was the choke dying every 3 months and needing a rebuild that put me off them.... other than that theyre a great carby!

PostPosted: Fri Jun 13, 2008 9:32 pm
by want33s
alien wrote:i dont think the issue with the aisin carb is its stalling - for me it was the choke dying every 3 months and needing a rebuild that put me off them.... other than that theyre a great carby!

Haven't had a drama with my autochoke but it wouldn't be too hard to convert it to cable choke with a warning light.
Jas.

PostPosted: Sat Jun 14, 2008 6:15 pm
by NIK
My stock carb was fine up and down side angles killed it and the bloody choke. Never ran one onmy webers and never needed it.
Theres a great thread on zuwharrie about diy hardleyableson carbs.
Nik

PostPosted: Tue Jun 17, 2008 5:24 am
by NIK
Picked up my weber, this thing is a work of art if it works half as good as it looks I,ll be happy.
Image

I also got a 88 u.s. spec stage 4 manifold, they have a different egr set up so it allows more extreme porting under the carb.
Image
Old manifold you can see were I had to taper it on the left as I couldnt take anymore out as the bolt holes for the adapter were in the way (inner side smaller port as it was for 32/36)

Image
New manifold you can see its cut straight down and equal both sides as both barrels of the 38 are equal in size.
Very impressed with the quality cant wait to try it out.
Nik

PostPosted: Thu Mar 12, 2009 6:58 pm
by seamsy
is anyone out there running dual side draft webers
i understand that a manifold would have to be fabricated which would more difficult on a sierra then others just because of the water jacket being located on the stock manifold

PostPosted: Fri Mar 13, 2009 8:43 pm
by brad-chevlux
seamsy wrote:is anyone out there running dual side draft webers
i understand that a manifold would have to be fabricated which would more difficult on a sierra then others just because of the water jacket being located on the stock manifold


would make it pig to drive off road.
a pair of small SUs could work well

PostPosted: Sat Mar 14, 2009 12:54 am
by JrZook
brad-chevlux wrote:
would make it pig to drive off road.
a pair of small SUs could work well


Why so mate? Side draught webbers have a central fuel bowl located at the bottom of the carb (less gravity dependance), hence they would be alot more suited to the larger angles then the downdraught variety.

I think redline did have a manifold to suit the 1.3 and side draughts at one stage.

Dan

PostPosted: Fri Mar 20, 2009 7:29 pm
by brad-chevlux
JrZook wrote:
brad-chevlux wrote:
would make it pig to drive off road.
a pair of small SUs could work well


Why so mate? Side draught webbers have a central fuel bowl located at the bottom of the carb (less gravity dependance), hence they would be alot more suited to the larger angles then the downdraught variety.

I think redline did have a manifold to suit the 1.3 and side draughts at one stage.

Dan


to much carburetor. would make los speed throttle control difficult

Re: who's got a weber on a sierra

PostPosted: Fri Oct 17, 2014 9:21 am
by Freddy
Hi Guys..joined a few years back but can't find login details.Just fitted a Weber to a Coily and going fine but not sure what to do with Charcoal Canister vacum line as there is only one port(dizzy) on carb.Do i just block it off (i was told it vents tank) or t-piece existing Dizzy vacum line,worried about fuel vapour finding its way into Dizzy.My brother posted on other Forums but no answer yet..... TIA .....

Re: who's got a weber on a sierra

PostPosted: Wed Aug 09, 2017 2:28 pm
by Puddles
So I bought a 91 SJ70 a few months ago and it's got a 32/36 weber on it. After a few little outings and some pretty steep descents - the flooding issue was getting pretty annoying.
The bloke I bought it from mentioned there was some trick you could do to get them running up and down hills (at the time I knew nothing of zooks let alone carbies) so I did some research and found out what to do. I finally got around to doing the mod and decided with the whole photobucket crap that's going on, I'll share my process in the hope to keep information alive.

The problem (from what I understand) is at extreme angled, the float tends to open up and fills the bowl with fuel... then pours out the vent which for some reason is vented straight over the top of the air correctors and floods the engine.
Image

The whole process is actually pretty straight forward - the longest part is letting glue dry.
Mines reverse mounted so it normally stalls going downhill - it makes sense when you look at how it's configured. Do want you want with the fuel - leave it, drain it, drink it or sniff it - I don't really care
Image

Getting the housing off it just the 6 x 8mm nuts, a breather hose on the filter plate and fuel inlet and the little pin holding the choke arm on (for the manual choke anyway)
Image

The rectangle hole just below the butterfly valves is what you need to block up. The tube to the right of it is what you'll drill into to create the new vent.
I used an old heat shield to cut a blanking plate and JB weld it to the hole.
ImageImage

Mix the bird crap up. I made a piping bag out of an old ziplock bag laying around.
ImageImage

Once that's all nice and dry, drill some holes in the moulding or use a dremel to cut an opening. This creates the new vent for the fuel to run into.
Image

Where the opening is for the moulding use a 5/8" tap to make a thread (you might want to drill it out some more first as it steps down and the thread wont be very deep otherwise) Use a brass barb with a 5/8 thread and whatever size nipple to attach a hose.
Image

I've currently got mine running into a container that can hold around 2 cups of fuel. Once that's full I pour it back into the tank. I think most people plumb them into the charcoal canister or run it back to the fuel tank. I'll probably create a better auxiliary tank from an old extinguisher or something later on.
Other than that, this seems to fix the incline issues these carbies have.