UK: 01564  783  192
Int: +44 1564 783 192

Close

If you know the part number you require, enter it here

'The Legend Rides On' - the most magnificent Royal Enfield book

A fabulous visual celebration of Royal Enfield motorcycles - very limited suplies!

more details
Seats

more details
View Hitchcocks from inside the building, click here and explore all areas
A behind the scenes look at Hitchcocks Motorcycles

« Back

Cabrurettor issues.. how to get mad!

Post a ReplyPost a Reply

Page  1 | 2 | 3 | 4 | 5 

Cabrurettor issues.. how to get mad!
Started at 07:17am on the 20th April, 2017 by Simplo
Simplo Subject: Cabrurettor issues.. how to get mad!
Hi all, this is Simone from Italy. Firts of all, please, forgive my bad english, I hope it will be enough to explain my problem. I own a Bullet 2007 350 STD, she never gave me any serious problem. About a month ago I take her out of the garage, as usual, and tried to let her start. Usually she gets running on firts o second attempt. In about 56 attempts I tried every kind of combination: with choke, without choke, with throttle, without throttle... swearing, not serating: nothing to do. Then I stardet standard checks: spark ok, valves ok, compression ok, sparkle ok... It seems no fuel come from the carburettor. "May be the float is locked" I tought. Than I removed the carb, cleaned it at reinstalled. At the first attempt the throttle cable broke. Ok, let's change it! I removed the carb again, disassebmled it and changed the cable. As I was reassembling it I saw the main needle does not fitted well in the hole, it was blended. May be I put something on it when it was removed and blended it. Ok, I connected to Hitchcock's shop and ordered a new one. Finally the new needle arrived and I reassembled the carburator. First attempt and OK! The bike started! On the next day I used her for a 100km run: perfect! Two weeks later I took the bike out of the garage again, tried to start and... nothing to do! No way! Other 77 attemps: with choke, without choke, with throttle, without throttle... swearing, not serating: nothing to do. All checks ok! Ok, I removed and disassembled the carb at least 10 times. Cleaned it with air, all passages ok! Tuned the float level and verified the main needle retainer is in the middle poisition. The only thing I achieved is that the bike starts with choke and, after 7 seconds, idle regularly without choke (as it always been for 10 years) . As soon as I turn the throttle the engine coughs and turns off. It seems not enough fuel reaches the engine. If the chocke is on the throttle seems to work almost normal. I tried everything: change the float level, retune the mixture, move the needle plier to richen the mixture.. nothing at all. I also straighten up the old needle and tryied it again... nothing! Any idea? Thank you for your patience reading all this...
Posted: 07:17am 20th April, 2017
Graham43 Subject: Cabrurettor issues.. how to get mad!
Did you replace the plug with a new one? All my start problems have been solved by replacing the plug. That is why I always carry a spare plug.
Posted: 08:22am 20th April, 2017
PeteF Subject: Cabrurettor issues.. how to get mad!
Beat me to it Graham.
It could easily NOT be the plug but worth a try for a few quid.
Posted: 08:25am 20th April, 2017
papasmurf Subject: Cabrurettor issues.. how to get mad!
Old fuel? Air filter dirty/falling apart? Air getting in somewhere it shouldn't?
Posted: 08:37am 20th April, 2017
Simplo Subject: Cabrurettor issues.. how to get mad!
Hi all, thanks for the reply... Plug is a brand new one and also the air filter. Also tried with old ones. I don't think I have air passages after the carb and before the engine... To detect air leaks I tried to start the engine without the air filter and (once it idles) covered the carb air intake whit my and... it shit down almost immediately. I was thinking at some fault on the mixture screw... any idea to check it?
Posted: 11:44am 20th April, 2017
papasmurf Subject: Cabrurettor issues.. how to get mad!
Have you removed the petrol pipe from the petrol tank to check if fuel is actually flowing freely?
Posted: 12:22pm 20th April, 2017
Adrian Subject: Cabrurettor issues.. how to get mad!
Papasmurf's idea to check the fuel pipe and the fuel tap is good, don't forget to check the air vent in the fuel tank cap too, in case it's blocked at all.

As your 350 Bullet is a late model, does it still have its Pulse Air Valve fitted? If so check the fitting into the carburettor flange and the exhaust pipe as a source of air leaks, or check the blanking plugs if the PAV has been removed.

A.
Posted: 01:48pm 20th April, 2017
Simplo Subject: Cabrurettor issues.. how to get mad!
Hi all, thanks again for the replies. The fuel line is ok, the fuel flows as expecxted, I know beacuse the small carb's tank is full of gasoline and also because with the choke or at just idle the engine can run for hours.. :D Yes, mine Bullet has the PAV system. It seems ok, but how can I check or bypass it? I just tried to close the little pipe that hangs downs the carb flange, but nothing changed...
Posted: 02:54pm 20th April, 2017
Mark M Subject: Cabrurettor issues.. how to get mad!
I'm not familiar with these carbs but is it possible to install the slide the wrong way round, ie with the cutaway facing the engine and not the airfilter side? I ask because a friend of mine once had the same symptoms on a Honda CG125 and I found that he'd done exactly this. The bike would start on the pilot circuit but drop dead if the throttle was opened.

REgards, Mark
Posted: 03:23pm 20th April, 2017
papasmurf Subject: Cabrurettor issues.. how to get mad!
Simplo, just because there is enough fuel flow at tickover does not mean there is enough fuel flow for faster speeds. You really need to remove the pipe from the fuel tank to check for a part blockage. At least that will find or eliminate a problem.
Posted: 04:15pm 20th April, 2017
Simplo Subject: Cabrurettor issues.. how to get mad!
Hi Mark, no way to install the slide in the wrong way, there is a cut with a pin that must be ligned or the carb doesn't close :D
Posted: 05:01pm 20th April, 2017
Simplo Subject: Cabrurettor issues.. how to get mad!
Hi Papasmurf, if i open the tank valve without the pipe the fuel drains.. also I can see it flow freely because my pipe is transparent... :( As I said: I'm getting mad
Posted: 05:05pm 20th April, 2017
Adrian Subject: Cabrurettor issues.. how to get mad!
Our hosts used to see a blanking plug for the PAV union on the exhaust pipe. I think there is a separate spacer between the carburettor and the head with the PAV take off connection. If so, you can simply remove this, if not, unscrew the little connector to the PAV pipework and use a plain screw with the same thread to plug the hole, with sealant as necessary.

Failing that, dump the Mikarb and treat yourself to a Dell'Orto PHBH 26 or an Amal carburettor!

A.
Posted: 05:59pm 20th April, 2017
Simplo Subject: Cabrurettor issues.. how to get mad!
Hi Adrian, thank you for your reply. Yes, there is a separate spacer between carb and engine, with the rubber pipe that comes from the PAV. I already tried to unplug the pipe and tap the plug, nothing changes. I didn't changed anything else on the PAV (not removed the metal pipe from the exhaust or other things in the left sidebox where the electric part of the PAV is but I don't think it does matter... I don't really know what to try again...I think my Bullet is the only 350 in my whole island (Sardinia), so no chances to try another carb. The only thing I did not yet donw is to remove the mixture screw and check it and the corresponding hole... last chance to try saturday morning :(
Posted: 07:06pm 20th April, 2017
AndyMc Subject: Cabrurettor issues.. how to get mad!
These are observations rather than experience of a350. It runs on choke. You have changed plug. Sounds like fuel issue. Check for air leaks. Also check for water in fuel. Maybe drain tank or use syringe / small bottle with fresh fuel from different supplier after draining float chamber. Check for rust in tank and blocked filter/ strainer. Good luck
Posted: 09:45pm 20th April, 2017
Creaky45 Subject: Cabrurettor issues.. how to get mad!
Interesting post. I suppose you have double checked the rubber between the carb and the manifold. With the engine idling spray around it with WD40 eg and see if it blows smoke. Could be a small crack in it impossible to see. I have had this problem. Be sure to let us know when you find the solution. Your timing should not be the problem as it idles ok, unless the advance is stuck on full retard. Unlikly though but twist the cam in the distributor to make sure it moves ok. Good luck. You need it with an Enfield.
Posted: 10:40pm 20th April, 2017
Leon Novello Subject: Cabrurettor issues.. how to get mad!
As Creaky45 says: My Bullet also suffered these symptoms, that is why I don`t have any hair now. The mechanic found a split in the rubber manifold between the carburettor and cylinder head. If it is 10-years-old, it is sure to be perished. Look at it carefully, bending it to expose any holes or splits.
Posted: 01:59am 21st April, 2017
Simplo Subject: Cabrurettor issues.. how to get mad!
Hi Creaky and Leon, thank you for your replies. I don't hink I have air leaks between carb and engine, my Bullat has no rubber pipe, but a metal flange with the PAV connector.. I'll recheck, anyway! Thank you!!
Posted: 09:14am 21st April, 2017
Simplo Subject: Cabrurettor issues.. how to get mad!
That's incredible. I rechecked all: plug ok, filter ok, spark ok, no air leaks... Carburettor is now cleaner than my kitchen... All passages are ok: main jet ok chocke air passage ok choke fuel passage ok fuel flows the float is working the throttle is ok... air/fuel screw is on 1 and 1/half turns from closed (as it always has been) Float is on 22mm (as it always has been) No other screws have been touched same behaviour: the engine starts at first attempt with choke on it runs good and RPM increase regularly activ with throttle (with choke on) it idles good with choke off it coughs and turns off as soon as I use the throttle I tried several air/fuel screw positions, it seems to go better (very little) closing it (as I thought there is not enough fuel) About the float: the PDF from Hitchcock says it must be between 24 and 26 mm but the carburettor on the PDF is different than mine. Mine always been at 22mm. Anyway I tried also to set it at 25mm, nothing changes... :(
Posted: 10:25am 22nd April, 2017
PeteF Subject: Cabrurettor issues.. how to get mad!
You haven't lost the thick washer/spacer under the main jet?
Posted: 11:36am 22nd April, 2017

Page  1 | 2 | 3 | 4 | 5 


Post a ReplyPost a Reply
Opening times: Monday - Friday 9am - 6pm | Closed: Saturday and Sunday
IF YOU ARE NEW TO THIS SITE AND WOULD LIKE INSTRUCTIONS ON HOW TO USE AND NAVIGATE IT, PLEASE CLICK HERE.
Units 7 & 8, Rosemary Court, Oldwich Lane West, Chadwick End, Solihull, B93 0EY, UK

© Hitchcocks Motorcycles Ltd. 2010 | Terms & Conditions

Back to top