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Monobloc-Resleeve or Buy New? #338330
10/15/10 3:41 pm
10/15/10 3:41 pm
Joined: Sep 2007
Posts: 101
Ohio
R
rmak Offline OP
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Posts: 101
Ohio
The old Monobloc on my 65 is giving me fits. I am constantly adjusting the idle. When the bike is warmed up, I can't get the idle low enough. When the bike is cold I have to turn the idle up. There are all other possible variations of idles on any given day. There is sometimes black smoke with a startup.

From what I've read, it sounds like the sleeve is worn or distorted.

I found a place that would re-sleeve the original carb. I've also looked at buying new.

Outside of cost, is there any reason to resleeve the old carb over buying a new one?

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Re: Monobloc-Resleeve or Buy New? [Re: rmak] #338334
10/15/10 4:06 pm
10/15/10 4:06 pm
Joined: Aug 2001
Posts: 7,669
scotland
triton thrasher Offline
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scotland
This isn't addressing your problem I know, but it actually shouldn't idle properly when cold.

If the threads that the ring on top screws onto are good, the carb is worth fixing.


Amateur Loctite enthusiast.
Re: Monobloc-Resleeve or Buy New? [Re: rmak] #338374
10/15/10 7:37 pm
10/15/10 7:37 pm
Joined: Jun 2007
Posts: 6,154
Maui Hawaii
HawaiianTiger Online content
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Maui Hawaii
Mike Gaylord used to sleeve the Monoblock but a sleeve was pressed INTO the body instead of shrunk around the slide. He no longer does this as far as I know. As far as sleeving is concerned, the last two Monoblocks I restored just required a new slide. I bought hard chromed slides for them and even though the body was worn a bit, the carbs function as intended and will last a very long time.
If you have large variations in temperature you can expect your bike to run differently according to the temperature. Here, the temp varies at most twenty degrees and my bikes don't run very much differently in either extreme. I still reach down and tweak the idle a bit from time to time.
If your carb has a sleeve already, it has possibly been sleeved by Mike Gaylord in the past. Otherwise Monoblock carbs did not come with sleeves.

Bill


Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Flying Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: Monobloc-Resleeve or Buy New? [Re: HawaiianTiger] #338379
10/15/10 7:49 pm
10/15/10 7:49 pm
Joined: Sep 2007
Posts: 101
Ohio
R
rmak Offline OP
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Ohio
I think I mistakenly referred to what I found as "re" sleeving. From the photos on the internet, the guy recuts the inside of the carb with a lathe and fits a sleeve down in. He then provides a slider that fits exactly. My carb is just an original Monobloc with nothing done to it.

Re: Monobloc-Resleeve or Buy New? [Re: rmak] #338426
10/16/10 1:11 am
10/16/10 1:11 am
Joined: Jul 2007
Posts: 594
australia
6
649 Offline
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australia
dont know if they do the same with monoblocs, but "resleeving" a Concentric usually means boring out the body to paper thin and more likely to distort and putting a sleeve over the slide which means a normal slide will never fit again...total waste of time and money and permanently destroys the carb...if someone would sleeve the carb body and use a standard slide yes, other way way never again


1970 tr6r dryframe
Re: Monobloc-Resleeve or Buy New? [Re: rmak] #338464
10/16/10 8:43 am
10/16/10 8:43 am
Joined: Oct 2003
Posts: 3,707
Emsworth, sunny south of Engla...
D
dave jones Offline
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Emsworth, sunny south of Engla...
My 389 Monobloc was really worn and, although the bike ran surprisingly well on the road, the idle was awful (as the others say you have to set this when the bike is fully warmed up). I had the carb repaired in the body bored out and the slide fitted with a stainless steel sleeve way and the result was a massive improvement in idle. It cost 33 as against about 130 for a new carb of this type. For the money the entire carb was cleaned inside and out and checked- it looked like brand new.
Dave

Last edited by dave jones; 10/16/10 8:44 am.
Re: Monobloc-Resleeve or Buy New? [Re: dave jones] #338931
10/19/10 9:32 am
10/19/10 9:32 am
Joined: Jul 2005
Posts: 604
back down the 'smoke',England
6T Offline
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back down the 'smoke',England
Hey Dave,where did you get it done?I've had 2 of the 'NEW' monoblocs and wouldn't buy another till they get them 'right!'....Cheers,6T


...I do not and cannot accept the principal that incompetence justifies dismissal...
T120R '67
6T 1965
T110 1958
Re: Monobloc-Resleeve or Buy New? [Re: rmak] #338937
10/19/10 11:11 am
10/19/10 11:11 am
Joined: Dec 2004
Posts: 9,663
Scotland
kommando Offline
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Scotland
I have had a mono and a Concentric resleeved by Alverstoke Restorations. Contact 02392 580708 harkin_3(at)hotmail.com

No point in buying new when after this it comes back vapour blasted and looking new.

Re: Monobloc-Resleeve or Buy New? [Re: rmak] #338948
10/19/10 12:16 pm
10/19/10 12:16 pm
Joined: Jul 2007
Posts: 594
australia
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649 Offline
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australia
mine were fine at first, but after a couple of years were sticking badly as the stainless steel wore so eneded up in the bin, as you cant just go and buy a new slide. also much more prone to warping from overtightening...if the bodies could be sleeved and use a standard slide that'd be the go


1970 tr6r dryframe
Re: Monobloc-Resleeve or Buy New? [Re: rmak] #338988
10/19/10 5:06 pm
10/19/10 5:06 pm
Joined: Jul 2005
Posts: 604
back down the 'smoke',England
6T Offline
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back down the 'smoke',England
...many thanks kommando,just looked them up,cheers...


...I do not and cannot accept the principal that incompetence justifies dismissal...
T120R '67
6T 1965
T110 1958
Re: Monobloc-Resleeve or Buy New? [Re: rmak] #339087
10/20/10 6:10 am
10/20/10 6:10 am
Joined: Dec 2004
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Scotland
kommando Offline
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Alverstoke use brass on the sleeves not stainless. I have a rock steady idle on an MX cam equipped B44.

Re: Monobloc-Resleeve or Buy New? [Re: kommando] #339111
10/20/10 1:28 pm
10/20/10 1:28 pm
Joined: Jan 2006
Posts: 7,175
Laredo (South) Texas, USA
GrandPaul Offline
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In order to really get the best results from an AMAL carb overhaul, you MUST replace the following bits:

Main Needle
Needle Jet
Main Jet

Combined with a proper body bore & sleeving, and a replacement or sleeved slide, the results are a carb that performs as new.

BeezAlex notes that these overhauled carbs can possibly run a tad lean with respect to the slide cutaway, you may need to carefully set up the carbs to get correct results.

Also, the float bowl covers on old monobocks are some of the hardest to get a good seal with. Re-faced bowl mouths and new covers are the hot ticket for a long-term fix.


GrandPaul (does not use emoticons)
Author of the book "Old Bikes"
Too many bikes to list, mostly Triumph & Norton, some BSA & European
"The Iron in your blood should be Vintage"
Re: Monobloc-Resleeve or Buy New? [Re: 6T] #339128
10/20/10 4:05 pm
10/20/10 4:05 pm
Joined: Oct 2003
Posts: 3,707
Emsworth, sunny south of Engla...
D
dave jones Offline
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Emsworth, sunny south of Engla...
6T- I too got mine done at Alverstoke. Definitely a stainless steel sleeve on my slide, however. Brilliant job and a good price and still working fine. Maybe you could ask for a brass sleeve or ask his advice.
Dave

Last edited by dave jones; 10/20/10 4:08 pm.
Re: Monobloc-Resleeve or Buy New? [Re: dave jones] #339194
10/20/10 11:43 pm
10/20/10 11:43 pm
Joined: Aug 2010
Posts: 590
Toronto, Canada
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Bola Offline
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Toronto, Canada
For what it's worth I had my Concentric carbs re-sleeved. They've been a tad problematic. The new sleeves are tighter in the bore making for a richer mixture at idle to 1/2 - fouling plugs. If you go with re-sleeved be sure to have the appropriate "air" space specifications followed.

Re: Monobloc-Resleeve or Buy New? [Re: rmak] #339222
10/21/10 6:51 am
10/21/10 6:51 am
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australia
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649 Offline
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australia
the other thing to remember if you want to change your slide cutaway its not just a matter of buying a new slide

Last edited by 649; 10/21/10 6:51 am.

1970 tr6r dryframe
Re: Monobloc-Resleeve or Buy New? [Re: rmak] #339225
10/21/10 7:02 am
10/21/10 7:02 am
Joined: Dec 2004
Posts: 9,663
Scotland
kommando Offline
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Scotland
Mine ran a bit rich just off idle, I took the next up slide from the spares box and used it to mark the new slide, I took a file to the cutaway until the slides matched. No more richness.

Checked the slides from both carbs, earlier Monobloc was bronze and the Concentric I had done later has a stainless slide which is unmarked. So Kevin has changed the material he uses but sure he could use either if asked.

Re: Monobloc-Resleeve or Buy New? [Re: 649] #339232
10/21/10 8:58 am
10/21/10 8:58 am
Joined: Aug 2001
Posts: 7,669
scotland
triton thrasher Offline
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Originally Posted by 649
the other thing to remember if you want to change your slide cutaway its not just a matter of buying a new slide


A brass slide cutaway can be built up with solder, as well as filed.


Amateur Loctite enthusiast.
Re: Monobloc-Resleeve or Buy New? [Re: rmak] #339376
10/22/10 6:40 am
10/22/10 6:40 am
Joined: Jul 2007
Posts: 594
australia
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649 Offline
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australia
has anyone else got a report on doing this a few years down the line apart from me...of course if its just been done and the old carbs were worn you'd be happy and the thing would run better...after a few years mine went in the bin and towards the end were worse than normal worn carbs had ever been...its paper thin walls left on the body that are the problem


1970 tr6r dryframe
Re: Monobloc-Resleeve or Buy New? [Re: rmak] #339409
10/22/10 1:29 pm
10/22/10 1:29 pm
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Bishop, Calif.
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desco Offline
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Bishop, Calif.
My Gaylord bored and sleeved carbs have been on my 72 for 20 years and I'm guessing 40,000 plus miles, no speedo. I only have to adjust them every couple of years when I pull them apart to blow the crud out. They are truly set and forget. I sent a set of brand new carbs for my 68 to Lund a few years back and have had the same results, set and forget. No slide binding, will idle all day, the only thing I have to check is cable stretch and adjust accordingly.


1968 T120R
1972 T120RV
Any advice given is without a warranty expressed or implied.
Re: Monobloc-Resleeve or Buy New? [Re: rmak] #339414
10/22/10 2:08 pm
10/22/10 2:08 pm
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Posts: 344
Central Illinois
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charliechan Offline
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Central Illinois

Last edited by charliechan; 10/22/10 2:08 pm.
Re: Monobloc-Resleeve or Buy New? [Re: rmak] #339497
10/23/10 4:26 am
10/23/10 4:26 am
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649 Offline
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australia
http://cgi.eBay.com/ebaymotors/AMAL...58QQptZMotorcyclesQ5fPartsQ5fAccessories

this guy sleeves bodies or slides...no association just saw ad on fleabay


1970 tr6r dryframe
Re: Monobloc-Resleeve or Buy New? [Re: 649] #339499
10/23/10 4:44 am
10/23/10 4:44 am
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Central Illinois
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charliechan Offline
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Central Illinois
Originally Posted by 649
http://cgi.eBay.com/ebaymotors/AMAL...58QQptZMotorcyclesQ5fPartsQ5fAccessories

this guy sleeves bodies or slides...no association just saw ad on fleabay



That's interesting sleeving the body instead of the slide. I'd like to know how that works out after long term use? Anyone know of this guy?

Last edited by charliechan; 10/23/10 4:44 am.
Re: Monobloc-Resleeve or Buy New? [Re: rmak] #340590
10/30/10 12:41 pm
10/30/10 12:41 pm
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649 Offline
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australia
from the AMAL site...maybe they just want you to buy a new carb, but it echoes my experience......quote
"Sleeving the Carburetter

There are solutions available to address body and slide wear which involve boring the mixing chamber body and fitting a brass, steel or aluminium sleeve to either the body or the slide. Sleeving is not recommended for the following reasons;

(a) Thinning the walls of the mixing chamber makes the carburetter more prone to warping when the flange bolts are being tightened.
(b) Sleeving the carburetter to an incorrect clearance between slide and body will make the carburetter difficult or impossible to tune correctly.
(c) Inadequate wall strength and tight clearances can cause the slide to stick dangerously.
(d) Poorly executed sleeving can dislodge or damage the spray tube.
(e) Slides in bored mixing chambers can only be replaced with a further sleeved slide.
(f) Poorly sleeved carburetters can have the slide locating lug masked to the point where the slide can override the locating slot and jam."


1970 tr6r dryframe

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