guzziriders.org - moto guzzi forum Homepage
Forum Home Forum Home > Introduction > Introduce yourself
  New Posts New Posts RSS Feed - V50 monza carburettor set up
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

V50 monza carburettor set up - Event Date: 01 Oct 2020 - 10 Oct 2020

 Post Reply Post Reply Page  12>
Author
Message
MGGGG View Drop Down
Falcone
Falcone
Avatar

Joined: 24 May 2018
Location: Swansea wales
Status: Offline
Points: 22
Post Options Post Options   Thanks (0) Thanks(0)   Quote MGGGG Quote  Post ReplyReply Direct Link To This Post Calendar Event: V50 monza carburettor set up
    Posted: 01 Oct 2020 at 09:55
Help! Been struggling with carburettor set up since getting this bike 2 years ago. Came with pod filters, which I renewed with replacements from Gutzibits. Runs very rich, tick over is fine, and when cold it’s fine, but after 5 miles it misfires Badly at anything under quarter throttle - unrideable! Plugs will be black with soot. Carbs have been thoroughly cleaned (more than once!) choke slides have been renewed, made sure there is play in the choke cable, though no need to use choke to start. Currently has 125 main jet, 50 pilot, 50 slide, and what I think is the starter jet is 60. Any recommendations on jetting? which I think must be the cause of the problems. Any help greatly appreciated.
Back to Top
c13pep View Drop Down
Senior Member
Senior Member
Avatar

Joined: 31 Aug 2017
Location: Doncaster
Status: Offline
Points: 2110
Post Options Post Options   Thanks (0) Thanks(0)   Quote c13pep Quote  Post ReplyReply Direct Link To This Post Posted: 01 Oct 2020 at 10:34
What position are the needles on, also these engines are upset if float heights are not as per the manual
Jet sizes look ok but its the needle and its jet that need to be spot on (preferably new) and ensure that the pods are not causing a restriction because their connecting rubbers are too small in the throat (this caused me endless problems on my first V50/3)
My own Monza does run rich low down but once out on the road this tends to clear but if started regularly in the garage plug fouling can become an issue
  

CHRIS


Edited by c13pep - 01 Oct 2020 at 11:14
you can`t have any fun in a straight line

Monza
Honda CB77 project

Back to Top
MGGGG View Drop Down
Falcone
Falcone
Avatar

Joined: 24 May 2018
Location: Swansea wales
Status: Offline
Points: 22
Post Options Post Options   Thanks (0) Thanks(0)   Quote MGGGG Quote  Post ReplyReply Direct Link To This Post Posted: 01 Oct 2020 at 10:50
Checked floats, exactly 24mm, needles 3rd from top.both cylinders affected, so assume must be to do with jetting.
Back to Top
c13pep View Drop Down
Senior Member
Senior Member
Avatar

Joined: 31 Aug 2017
Location: Doncaster
Status: Offline
Points: 2110
Post Options Post Options   Thanks (0) Thanks(0)   Quote c13pep Quote  Post ReplyReply Direct Link To This Post Posted: 01 Oct 2020 at 11:50
Apologies I hadn`t noticed the comment about below quarter throttle which suggests that the problem is prior to the needle valve starting to work. Recently I have changed my plugs to BP7ES to cure the same problem of plug fouling which seems to have done the trick. All the bikes previously have come with 
BP8s in and I never bothered to cross reference the ones in the manual.

CHRIS
you can`t have any fun in a straight line

Monza
Honda CB77 project

Back to Top
Ken-Guzzibear View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 13 May 2014
Location: Sileby Leics
Status: Offline
Points: 9454
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken-Guzzibear Quote  Post ReplyReply Direct Link To This Post Posted: 01 Oct 2020 at 12:05
The usual set up for pod/k&N filters is 10% up on standard for main leaving the others alone, Eurocarbs are very helpful in setting up the Guzzi Carbs 
The Older i Get, The Better I Was
Back to Top
c13pep View Drop Down
Senior Member
Senior Member
Avatar

Joined: 31 Aug 2017
Location: Doncaster
Status: Offline
Points: 2110
Post Options Post Options   Thanks (0) Thanks(0)   Quote c13pep Quote  Post ReplyReply Direct Link To This Post Posted: 01 Oct 2020 at 12:11
https://guzzitek.org/plm/pb/V50_3_PLM.pdf
I find this very useful and a lot clearer than the manual for looking at the finer detail, the numbers correspond to the Fowlers spares pages
Apologies if you`ve already got it but `every little helps`

CHRIS  
you can`t have any fun in a straight line

Monza
Honda CB77 project

Back to Top
Ken-Guzzibear View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 13 May 2014
Location: Sileby Leics
Status: Offline
Points: 9454
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken-Guzzibear Quote  Post ReplyReply Direct Link To This Post Posted: 01 Oct 2020 at 12:14
Must have been the lockdown re builds there seems a fair few small blocks with carb/timing issues recently
The Older i Get, The Better I Was
Back to Top
MGGGG View Drop Down
Falcone
Falcone
Avatar

Joined: 24 May 2018
Location: Swansea wales
Status: Offline
Points: 22
Post Options Post Options   Thanks (0) Thanks(0)   Quote MGGGG Quote  Post ReplyReply Direct Link To This Post Posted: 01 Oct 2020 at 12:24
Thanks Chris. I have BP6 at moment. I’ll try the BP7. At moment I have the carbs in bits, so I’ll wait to see what response I get regarding the jetting just in case I need to change anything there. I am assuming that as it’s running far too rich I need smaller jets? Especially the pilot jet which is the operative jet under quarter throttle. It is 50 at the moment, while standard I believe is 52.
Back to Top
Ken-Guzzibear View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 13 May 2014
Location: Sileby Leics
Status: Offline
Points: 9454
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken-Guzzibear Quote  Post ReplyReply Direct Link To This Post Posted: 01 Oct 2020 at 12:37
the NGK BP6ES is hotter than the BP7ES and 2 grades hotter than BP8ES

The Older i Get, The Better I Was
Back to Top
AdrianW View Drop Down
Senior Member
Senior Member


Joined: 05 May 2019
Location: Bristol
Status: Offline
Points: 993
Post Options Post Options   Thanks (0) Thanks(0)   Quote AdrianW Quote  Post ReplyReply Direct Link To This Post Posted: 01 Oct 2020 at 16:42
My V35II arrived with Pods (PO invoice from Gutsibits) and ran rich.. Jets were standard spec.

I replaced choke mechs (manual in place of cable but it's really the plungers that need checking).
Then I replaced the float needles, needle jets and needles themselves (mine were corroded, bike had allegedly been stood a while at one point). Plugs I think are B7's..

Now runs fine, nice plug colour. Tickover is a bit fast when warm but I'm not touching anything for the time being !!

Good luck with yours..
Adrian
Bristol UK
Back to Top
c13pep View Drop Down
Senior Member
Senior Member
Avatar

Joined: 31 Aug 2017
Location: Doncaster
Status: Offline
Points: 2110
Post Options Post Options   Thanks (0) Thanks(0)   Quote c13pep Quote  Post ReplyReply Direct Link To This Post Posted: 01 Oct 2020 at 18:44
I would think that the plugs are the source of your problems as the jetting seems ok 
Strangely on the NGK website cross referencing the plugs in the manual gives BP7ES whereas checking using MOTO GUZZI gives B8ES

CHRIS


























Edited by c13pep - 01 Oct 2020 at 18:50
you can`t have any fun in a straight line

Monza
Honda CB77 project

Back to Top
MGGGG View Drop Down
Falcone
Falcone
Avatar

Joined: 24 May 2018
Location: Swansea wales
Status: Offline
Points: 22
Post Options Post Options   Thanks (0) Thanks(0)   Quote MGGGG Quote  Post ReplyReply Direct Link To This Post Posted: 01 Oct 2020 at 19:43
Thanks for all the responses, just great. I believe that standard main jet on monza is 118, a 10% upgrade would be 130! Going to stick with the 125 jet currently fitted for now (especially as it seems to be seriously over fuelling already) and try the bp7 plugs. If that does the trick you’ll here me whooping from wherever you are! Thanks again, and stay safe.
Post an update When I’ve put it back together.
Back to Top
George View Drop Down
Senior Member
Senior Member


Joined: 28 Sep 2018
Location: Prestwich
Status: Offline
Points: 113
Post Options Post Options   Thanks (0) Thanks(0)   Quote George Quote  Post ReplyReply Direct Link To This Post Posted: 04 Oct 2020 at 10:54
Hi and good morning. I have an ongoing post with my V50 (initially posted as ignition problems by George) and I'm almost at a point where I am about to give it another try (after I can get a 4.5mm countersunk screw that holds the choke chamber in place). I have done all the normal checks and replaced all jets as suggested in previous posts. The engine 'seemed' to run best on the left cylinder with the mixture screw set at a half turn out from full in position - it ran very rich with the screw one and a half turns out . An inspection of the taper tip at the very end of the mixture screw showed the tip to be in very poor condition (actually spirally grooved and rough when checked with a 20 times magnifying glass). I have recently renewed the mixture screws, which have a nice smooth taper, and during recent engine runs it seemed to be running better even with the screws set at around the one and a half turns out as suggested in the manual. It may be worth checking the condition of the mixture screw tips. My project is ongoing and I'm going to try another set of plugs now that I've had a quick look into he LHS cylinder head.
Best Regards - George 
Take care - be aware
Back to Top
MGGGG View Drop Down
Falcone
Falcone
Avatar

Joined: 24 May 2018
Location: Swansea wales
Status: Offline
Points: 22
Post Options Post Options   Thanks (0) Thanks(0)   Quote MGGGG Quote  Post ReplyReply Direct Link To This Post Posted: 04 Oct 2020 at 11:47
Thanks for the information George just been out to check mine and they do seem ok, not perfect, so if plugs don’t improve it they’ll be my next move. My understanding is that they control the air flow, so screwing them in is richening the mixture, while screwing them out is weakening it?? Have I got that wrong??
Back to Top
iansoady View Drop Down
Senior Member
Senior Member
Avatar

Joined: 23 Jul 2017
Location: Redditch
Status: Offline
Points: 2402
Post Options Post Options   Thanks (0) Thanks(0)   Quote iansoady Quote  Post ReplyReply Direct Link To This Post Posted: 04 Oct 2020 at 11:51
That sort of damage is usually caused by someone screwing the mixture screws tightly home. It often damages the seating as well......
Ian
1952 Norton ES2
1986 Honda XBR500
1958-ish Greeves/Triumph in progress
Back to Top
 Post Reply Post Reply Page  12>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.105 seconds.