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View Full Version : Mikuni RS 36mm on a 1200 Bandit ?



MTBEERWAH
08-08-2018, 09:02 PM
Hey all,
So, I've got 3 bandits. Two gen1's and a gen2.
One of my gen1's CV carbs is giving me the "Tom Tits"...big time.
I've pulled it apart, easily 10 times, changed as much as possible with new parts, eg:
Needle &seats,
O-rings throughout,
Emulsion tubes,.....blah blah blah....still has the symptoms of a massive air leak.
Put it on the bike and run it, spray all areas related to possible air leaks, with no sign of major leaks.
There is a slight change in character around the butterfly linkages on No: 4, but not enough to make it run like a piece of shit it does. I've used my lazor temp gun on the header to try and identify which carb is fucked, and they're all the same temp.

Anyway.....I'm sick of chucking money at the stupid CV. I can't find a second hand one, and one I would trust as well, so i'm contemplating an RS 36mm instead.

Key concerns is fuel economy vs Cv ??

What's people's experience with Mikuni RS 36mm vs stock ??
And again, this isn't because I want to, it's just because of circumstances, that lead me to this point.

Cheers in advance, John.

GammaBoy
09-08-2018, 12:22 PM
You don't fit RS Mikunis if you care about economy.

What's it doing? Have you tried swapping the carbs between bikes to see if the problem follows?

MTBEERWAH
09-08-2018, 04:05 PM
Hey mate,
Yeah, that's what I assumed....gas guzzler.
Was speaking to mikuni-oz, and he was doing the selling ploy, hence why I'm trying to get feedback on the RS's. Just didn't know if it could be leaned out a bit, or not wise to even contemplate.

Tried swapping my other CV carbs already. Definitely a carb issue. My other carbs run perfect on both bikes.
Problem carbs act as if there's a massive air leak, back firing and running on 3 cylinders.
Trust me, I've been over them with a fine tooth comb, with the other carbs side by side, totally dismantled, and set back to factory specs.....multiple time's with ever time having the same outcome.
I've tried eveything. I need another set, but not paying a stupid price for 20yr old carbs.
It would have almost been cheaper for me to buy the RS's, for the money I've been chucking at them.

GammaBoy
16-08-2018, 09:52 AM
If you want economy, inject it. If you want to develop forearms like popeye, and revel in crisp response, awesome sound and general awesomeness, put flatties on it.

8384

rod185651
16-08-2018, 06:58 PM
^^^ Post of the week ^^^

MTBEERWAH
17-08-2018, 02:33 PM
Yeah.....I got no response to that. ...

GammaBoy
20-08-2018, 08:23 AM
Yeah.....I got no response to that. ...
Flatslides will give you the response you need!

MTBEERWAH
22-08-2018, 01:36 PM
Ha ha....yeah, I know what you were laying down, just had no response to the caption.
Maybe do they run on Napalm.
"That gasoline smell"

Hagarr
02-04-2019, 01:42 PM
I did the same, rebuilt a set of 40mm CV's which cost me enough to buy a set of flatslides, so next time I did.

36MM RS Flatslides for $750 cheaper by half.

MTBEERWAH
09-04-2019, 04:36 PM
I'll have to do some research on them. I'd like them, but not if they're going to drink like a fish.
Whats yours like on juice if taking it easy ??

Gix11
10-04-2019, 09:44 AM
Supercharger didn't like hi Flatslides and took them off as he reckons it's "All or nothing" all the time. Great for drags or racing, but hard work on the streets. Have you ridden yours yet Danny?

GammaBoy
10-04-2019, 12:41 PM
Get them set up right and they're not all or nothing, they're fine on the street.
Just had a thought - the CVs you've been having trouble with - are they like the GSXR "Slingshot" carbs with the brass tube on the side? Those brass tubes are fairly well known for cracking/being fucked by ham fisted numpties, and it introduces an air leak into the thing from what I can gather. Can also happen with the tubes for the vac nipples for balancing that run up to the carb top.

For reference, the Kat would consume ~16-17 litres in 220km of giving it a hard time through the hills. Never had the patience to do a highway run to see what it was like at constant throttle.

Hagarr
10-04-2019, 01:22 PM
I'll have to do some research on them. I'd like them, but not if they're going to drink like a fish.
Whats yours like on juice if taking it easy ??

Just fitted and ready for test ride so not sure but with the cams and engine setup along with a dummy (9-10 litre) Ali tank it's going to be interesting how far I get!

MTBEERWAH
10-04-2019, 10:12 PM
Gammaboy,
yeah they're fairly well identical to the slingshot.
I've now swapped out the troubled carbs with another set I found, and the bike now runs fine. BUT... with the fuckup set, when I was still tinkering with them, I sprayed all around the carb looking for idle discrepancy to try and find a leak. The only place that made a slight difference in idle, was around No:3 and No:4 butterfly pivots, but it wasn't enough to upset the running. I'll get back to them one day to have another crack at them, as I've got another Gen1 sitting there waiting for attention.
16-17L to 220k's is a bit scary for me. In the time I first put this page up, I'd got another set of carbs, and ridden down to Phillip GP. I just cant do any trips like that with poor economy. At the moment with the bike fully loaded with gear, and going through the snowy alps, giving it a hand full, it was getting 17.9Km/L. Taking easy where I had no choice to, was getting 21.5 km/L.
I know it's not all about economy, we all like to be idiots....well I do anyway, but there's got to be some kind usability, unless it's a dedicated purpose, and in that case, I'd get a pair of flatties and play with them.

Hagarr,
So you've got cams etc ?
I've also got a Gen2 Bandit with gix cams, 1216 kit, and head flow. These have got better CV carbs on them, than the Gen1 bandits, but with the mods I've got, along with an open airbox jet kit, if I'm giving it a gut full it gets about 13.9km/L, which is the same economy as flatsides if smashing it.
Will be interesting to see how it works out for you.
So are your flatslides new out of the box, or second hand? I spoke to the Mikuni dealer in Townsville, and he was saying I shouldn't have to jet a new set, just use them straight out of the box. ...but I don't no about that, especially if you've got mods going on.
I've bought a wideband sensor to measure A/F ratio, which all I've got to do is weld a bung in the collector, so I'll do that on all three of my Bandits, regardless of what carby setup is on them, to try and get the perfect A/F for maximum affect and usability.

Hagarr
18-04-2019, 01:52 PM
Hagarr,
So you've got cams etc ?
I've also got a Gen2 Bandit with gix cams, 1216 kit, and head flow. These have got better CV carbs on them, than the Gen1 bandits, but with the mods I've got, along with an open airbox jet kit, if I'm giving it a gut full it gets about 13.9km/L, which is the same economy as flatsides if smashing it.
Will be interesting to see how it works out for you.
So are your flatslides new out of the box, or second hand? I spoke to the Mikuni dealer in Townsville, and he was saying I shouldn't have to jet a new set, just use them straight out of the box. ...but I don't no about that, especially if you've got mods going on.
I've bought a wideband sensor to measure A/F ratio, which all I've got to do is weld a bung in the collector, so I'll do that on all three of my Bandits, regardless of what carby setup is on them, to try and get the perfect A/F for maximum affect and usability.

Yes Ivan Tighe (Big suckers can't remember the numbers!) 78mm pistons so about 1108CC hence I reckoned the 36's should be Ok, APE Springs and retainers running STD New Valves and I'm not a real Top End junky like a lot of guys more a bottom and mid Man and with a six speed box should be interesting.
I've had a small (yet to determine actual size) Ali fuel tank which sits under a gutted original Slabby tank so not sure how the range is going to be but I didn't build this to be a tourer.

I'd love to show you an image but I've failed miserably!

MTBEERWAH
19-04-2019, 08:30 AM
Totally agree with against the top end thing, I like to be able to torque out of a corner, not have a peaky useless thing, but my engine didn't turn out the way I wanted it. It really has no power until 4000rpm, so you can't short shift by using low down torque. My stock gen1 shits on my 1216 down low to mid range. Due to the build and set up, i'm contemplating ripping the head off and going back to a standard head, and just leave it as a 1216. That's what the bandit engine is better known for...low to mid range. If I could go back in time, I certainly wouldn't have blown the stupid amount of money I've spent in trying achieve solid low to mid range torque, when all I should have done is the 1216 piston kit only. No cams or port flowing, then time after time trying different cam degrees, dyno tunes, exhaust systems, jet kits and airbox mods.

Good luck with yours, and keep us informed.

Hagarr
29-04-2019, 02:17 PM
My 1216 has standard cams but ported head and not sure of compression ratio (can't remember what Wiseco pistons it has), but LOTS!

When first built (1996) had 148RWHP and a fkn Torque monster, rebuilt carbs Ten years later and Dyno 142RWHP with a slight loss of comp in #3 but acceptable given the cylinder head has never been off in over 20+ years!

I'm now pulling 17 + 44 Sprockets and with all fairing back on (even bottom) still pulls up wheel at 6k every day!
You don't need big Sticks to make good streetable power.

I'll try some pics again soon!

MTBEERWAH
30-04-2019, 10:43 AM
Hope it works out for you. Pics would be good.

My Gen2 1216 did make 144rwhp. That was with full Hindle system. I had to ditch the extractors as it was robbing low tomid range torque. Nothing below 6000....was shit. After putting the stock headers back on, it starts to spool at 4000, but still not my kind of riding. So with stock head and 1216, should pull from 2500-5500 solidly. It's how I like to ride now. Torque out of corners, not peak out of corners. This way, will have controlled feeding and short shifting.

Now for the bad news. Last week some scum bag fucker stole my Gen1.....not fucking happy !!!!
Was my main source of transportation and favorite bike. Spent alot of time and money getting the bike to how I like it. Just gotta let it go, but not easy to do so.

ozzy1100
30-04-2019, 07:17 PM
That is well and truly fucked

Hagarr
01-05-2019, 04:55 PM
Hope it works out for you. Pics would be good.

Now for the bad news. Last week some scum bag fucker stole my Gen1.....not fucking happy !!!!
Was my main source of transportation and favorite bike. Spent alot of time and money getting the bike to how I like it. Just gotta let it go, but not easy to do so.

That sucks!

Gix11
02-05-2019, 10:12 AM
That is fucked! How did they get hold of it?

MTBEERWAH
02-05-2019, 04:02 PM
I went away for work for 3 weeks, and had three bike parked side by side in my car port beside the house.
Second in command woke up easter Saturday to find it gone.
I've got so much shit in my shed that I couldn't fit the bike's in. Well fuck me there's room now, I can tell you that.
I'm scratching my head about the steering lock. ....
The other 2 bikes were locked. ..did I forget ????? I don't think so. They took the bike cover too.
I live in a cul-de-sac, with a sloping driveway, that leads to a down hill secondary street.
Is it someone close by....did they have a trailer or a van.....
They've obviously been watching me knowing I wasn't there.
They knew what they were doing, as it was raining easter Friday night/Saturday morning, so masked by rain noise.

So now...homeland style security. Coming on my property without consent, may lead to bad things.