Monobloc or Concentric?

[Hubie]

Thought I would pose a question as I have one of each.  Do you think a monobloc is better than a mk 1 concentric?  I have a monobloc on my super meteor and a mk1 concentric on my golden flash.  It is supposed to have a monobloc on it and I was thinking of going back to original.  It is the only non original thing on the bike save for the indicators.

Cheers

Hubie.

[trevinoz]

It is the only non original thing on the bike save for the indicators.

That is a rash statement, Hubie!
   

Carby wise, I always use the original type. Keeps the rivet counters happy.
Trev.

[Triton Thrasher]

I don't think you'll notice a difference between Monobloc and Concentric if both are in tune.

[LJ.]

Probably as Thrasher says.... But I think the Monobloc is a better looking carb. Never had any problems with mine, dunno why people go for the Concentrics...

[MG]

dunno why people go for the Concentrics...

cause they are cheaper in case you have to buy a new one   

[Triton Thrasher]

Triton Thrasher, thats a bit like saying there will be no difference between the performance of a 1970 escort and a 1980 escort,

No it's not.  Those cars don't even weigh the same.

I believe either carb, if in tune, will be satisfactory to the chap who asked the question. I have not found Monoblocs to be noticeably better or worse than Concentrics.

I would say, if the bike is running well on a Concentric, time spent tuning a Monobloc might be considered wasted time.

Which features of the Mk 1 Concentric do you believe give it the superior performance?

[bsa- bill]

Richard I use Firefox it has a  spell checker and works just fine here.

All the best - Bill

[a10gf]

Offtopic: (these comments refer to a post that was removed) Yes, the Firefox spellchecker is 1st class.
See these tips on how to safeguard any online writings.

[Triton Thrasher]

Just 45 years riding bikes no other evidence to support my comments
I prefer mikuni's
Richard
sorry but had a long reply typed but lost it oh how i wish this had a spell checker so I would not have to copy and paste

We're too nice to say anything about your spelling!

The plural of Mikuni has no apostrophe though.

[beezalex]

It depends on what you want.  Both have their pluses and minuses:

Construction quality: Monoblocs seem to not wear their slides out as rapidly and are not distorted at the flange quite as easily as Concentrics.

Sleeving: Monoblocs are more difficult to sleeve and I have found that the slide cutaway has to be modified after sleeving as for some reason they run richer on the slide.

Idle circuit:  All but the early concentrics have a pressed-in pilot jet which is closer to the spray holes and thus seems to have better response and is not as suceptible to flat spots off idle.  The downside is that this pilot clogs much easier and is much harder to clean out on concentrics.

Float chamber:  Monoblocs sometimes idle eratically or have difficulty starting on a sidestand due to the offset float bowl.  This usually can be cured by enriching or leaning out the idle when upright but it's a compromise.  Concentrics are unaffected by lean.  BTW, claims that monoblocs will change mixture in turns due to the offset bowl are vastly exaggerated.  Unless you ride like rossi, the balance of cornering and gravitational forces pretty much keeps the float level constant.

Flow:  Monoblocs are smooth-bore carbs and will actually flow more for the same bore size than a concentric.  Whether this translates into more performance depends on how well your head flows.

[Richard]

We're too nice to say anything about your spelling!

TT I always knew that!

The plural of Mikuni has no apostrophe though.
[/quote]

Whats a plural?
 
Alex you all know I chuck the A10 around worse than Rossi"
All I can say is that years ago we always fitted the concentrics in preference to the monobloc, perhaps we were just misguided youths
Richard

[Triton Thrasher]

There was a while when the only available replacement carb for Brit bikes was the Concentric.

[Hubie]

Continuing with the off topic, its very refreshing to see people concerned with correct spelling and grammar!  You should see some of the sites here in Australia!  just check the netrider forum for example!!

As far as the carb question I posed goes, I was just thinking along the lines of originality.

Cheers,

Hubie.

[trevinoz]

I read an article which compared the 1966 Norton Atlas which had two Monoblocs, a LH and RH, and magneto with a 1967 model which had two Concentrics and coil ignition.
The 1966 model out-performed the '67.
Trev.

[RGS man]

I have just bought a new 389 monoblock for my RGS, I guess it would be great if I could ride it!!!
I still have no front hub, therefore no front wheel. wth regard grammer, I live in Aus, I dont thing they even teach it here!!!
Cheers  Mark