changing carbs

Hey Bob

I'd be wary of buying used GSXR 34mm flatsides as they are often worn beyond service limits and are effectively scrap hence the low prices. Note......I'm not refering to the CV's here.

                            Cheers
                                    Matt
 
mcnicol said:
sfc1000uk said:
you can buy brand new RS36s in the US for less than half the price you'd pay here

There's a used set of RS38 on Uk ebay that are bid up to ?530 so far & a brand new set on US ebay is ?475.
Click to expand...

Bob

That would be a liquidation price, there's lots of bike shops going bung, also who wants to keep inventory on accessories for 20+ year old bikes (which is what the RS36s were mostly sold for)? I've been doing ongoing searches for RS36s in the states for quite some time, believe me new ones are usually sold for full retail (or close to it), around $US1000 (depending on model).
Although there's been some phenomenal deals on used ones, I missed one set that went Buy It Now for $120. Some can be pretty ratty, though (like the "fire sale" ones PLC bought, Paul what do you think your "bargain" Mikunis actually ended up costing you?).

Ken
Click to expand...

Hi Ken

laughing out loud..... the answer is that the knowledge I gained in the repeated assembly/install/disaster/removal/rebuild and re-adjust/float bowl leakage/bent con rod replaced with Carillo's was priceless and I will carry that knowledge for the rest of my life, along with an empty wallet...

buying Red's kit would have been a LOT cheaper, but hard won practical knowledge has a value! I can noe rebuild and set up a set of RS 36's in the dark, with one hand tied behind my back, while standing on my head.

Paul LeClair
 
Dellortoman said:
Youn should be able to get Dellorto's to run cleanly.    They're pretty simple carbs so there's not much can go wrong with them.
Click to expand...

Maybe, Cam.

But they wear extremely fast, even more so once wear sets into the carb body.  Slides are soft as cheese and are often worn beyond service limits within 10000km if used in worn housings.  Then there's the linkage shafts, the bushes are worn on just about every bike that enters my workshop and more often than not, the shafts have had it too!

Refurbing a triple set of Dellos can set you back almost ?400 in parts alone, excluding labour!  And then the housings are still worn..... ::)  A new set will cost around ?600.  The linkages and domes need to be taken from the old units, if the shafts are shot, over ?100 just to get them back into decent shape!  Drilling the housings to take the spacing bracket and the vacuum fittings comes extra....

So, a set of new Mikkies is a definite option, even a used set will see you through quite a few more miles/kms than the old re-built Dellos.

piet
 
sfcpiet said:
So, a set of new Mikkies is a definite option, even a used set will see you through quite a few more miles/kms than the old re-built Dellos.

piet
Click to expand...

...and deliver more torque, quicker response of the engine etc. etc. etc.
 
Can someone post a pic of Miks close up on a RGA as I havn t seen them on one please.

Shaun
 
Hi,

Looking back over the post, am I right in assuming that Steven's (Kiwi Laverda) carbs are downdraft?  And Steve B's (breganzane) carbs are they also downdraft?  The Triumph CV carbs (Mikuni & Keihin) are sidedraft.

I have a 180' Series 2, and just wonder what angles are involved?  I think the engine is 21'?  The Triumph connectors are 11'?

Fyi, I have a suitable set of downdraft carbs laying idle in my garage, as well as having Triumph sidedrafts.

Thank you for any advice and information you can give.

Geoff
 
Hi Geoff,

Well I would say any carb from an oil cooled GSXR or early Hinkley Triumph is definately side draught.  I would consider the FCR's on Lothars bike to also be side draught.  The term is related to the orientation of the airflow, so to be "downdraught" in my book, the carb port has to be 45deg or greater from horizontal.  Carbs I would consider downdraught - early Yam FZR, Hon VFR, etc.  FCR's have a float bowl adapter for applications at greater than xx degrees.
Any carb mounted to a Laverda would by definition be sidedraught, the cylinder is at 15deg and the inlet port a further 12deg - 27 from horizontal.
It's nothing much more than a marketing term anyhow, air is air and it will go where the low pressure is, the main "thing" with the term downdraught is it usually might inply a straighter port to the inlet valve, something that is totally impossible with a stock Laverda triple head due to the inlet bucket bore being completely and utterly in the way.

Cheers
Steve
 
Hi Steve,

the Keihins are only available (to my knowledge) as Horizontal (float-bowl is almost straight under the carb) and Downdraft (float-bowl is angled at roughly 45?)

The Horizontal are recommended from 0? - 35?, the Downdraft from 28? - 90? (!!), but with some degree tolerance. So - officially, mine are Downdraft, though they are installed almost horizontal.
 
Thanks Keith,do they have a return cable on them like most and how much do you expect to pay for a set,use the same intake and out take rubbers to I see.

Shaun
 
Hi,
Thank you for the good feedback.
I have looked at the downdraft carbs I have laying around, and I think they are from an early ZX7 - Keihin CVKs.  I can certainly see the difference now, and understand that the pictures are sidedraft.  Thanks.

I am still confused about the angles, and see mention of Red's angled inlets.  Are these to help miss the carb hitting the frame (on a 180' series-2?), as well as perhaps matching the carb bore?  I realise the different model carbs could have a different headroom requirement.

Thanks again for the help.

Geoff
 
I bought a set of red's angled inlet stubs for 3 reasons:

#1: clearance of carbs with frame (monoshock location)
#2: clearance of fuel tap with choke knob (on Mikuni RS36s)
#3: they look really trick!  8)
 
Grant said:
I bought a set of red's angled inlet stubs for 3 reasons:

#1: clearance of carbs with frame (monoshock location)
#2: clearance of fuel tap with choke knob (on Mikuni RS36s)
#3: they look really trick!  8)
Click to expand...

I used Red's angled intake manifolds for simialr reasons, although Grant's item 1 doesn't apply to my bike,so

#4 they bring the float bowls of the RS 36's closer to level;
#5 dropping the carbs closer to level frees up space under the frame to ditch the stock air box and install really big oval K & N individual filters which flow a lot more air than the air box does even when punched full of holes;
#6 the angled manifolds are beautifully made, seal better, and much stronger than the el cheapo stock cast pot metal Laverda intakes which break and leak air, cooking valves

Paul LeClair
 
Hey...

I wonder how a set of Mikuni 29mm smooth-bores will work on a RGS motor?? I just bought a set, with "popy" cams and pistons for my Z900 (well soon 1105cc) and there is another set laying there...  ;)
 
Scorch,
you would need minimum 34mm Mikis and maximum 38mm.
This would be linked to opening up the ports accordingly.

Then you need 38mm ID downpipes and big collector and outlet pipe (don't like to use the word silencer).
Cams, cam timing, piston size and compression next.
Programmable ignition plus new coils too.
Balance and lighten the crank, bigger oil pump.
Best throw in a set of Carillo rods.

Then you need to stop it and make it go round corners.

Big gains to be made.

There a few in this stage of tune out there, owners on this forum.
 
Grant said:
I bought a set of red's angled inlet stubs for 3 reasons:

#1: clearance of carbs with frame (monoshock location)
#2: clearance of fuel tap with choke knob (on Mikuni RS36s)
#3: they look really trick!  8)
Click to expand...

4)Nominating me for Oz residency :D
 
A bit of trivia but if and when he does he's not going to be "just around the corner". If Grant ends up in Perth it's only a shade over 4000 km's to Red's place. A bit shorter (distance wise) as the crow flys if he goes via the Gun Barrel Hwy and Simpson Desert but you need a good 4WD and all the appropriate safety equipment. You could find out off Rob about converting one of your triples into a version of that rugged sidecar he posted pictures of earlier in the year. That was a classic.


Chris
 
I am planning to locate 1.5 hours drive from Rob.

Looks like POP will not be in an ideal environment over there.
Never mind, I have still got a mountain of spares so could start on POP2 the sequel. I always fancied an enduro triple.

I also have my eye on a 3C currently, but that will be kept as is, as my first one was a 3C. Lovely old bikes.

I do want to see as much of Oz as I can and am already hatching a plan across the Nullarbor.
 
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