Rich mixture and fouled plugs

I have found that a new set of stock slides and a new pilot jet cures most carb problems, gives good running and good idling.

Previously robert_tuck wrote:

After replacing most of my ignition system on the 99 (it was old anyway) I'm still in the same place. Too rich. Was puzzled why the needle needs to be in the top notch (should be position 3) ,studying the new chrome plated slide I find that its longer than the orriginal one ,So thats why. So much for new parts accuracy I will have to chop a bit off the bottom., For some reason the idle mixture is also far too rich , The thing will idle with the mixture screw taken out!. I suspect the idle airway is clogged ,Tried normal cleaning methods ,a sonic bath is next. The fuel level is spot on (new parts) My growing collection of fouled plugs begs the question , How to clean them ? Sandblasting is not kind to modern plugs which are formulated to work well with lean mixtures supplied by fuel injection and are not expected to cope with rich mixture fouling. I think a soak in a powerfull decoking solution may work. Yes Anna I tried your plugs!.

Hello do not use shot blasting It dose not work and fouls up the porcilin in the middel of the plugs use injection fuel cleaner , and now for you carburettor cure, Now you know the fuel needle valve on top of the float , well the housing it fit in dose not aways fit true to the carb body so what you get it the float needle letting the float come up by 20thou just enough to cause fooling what you need to do is unscrew the needle valve body and file flat the carb body about 20 thou and then fit you float needle body with a tin paper washer and you find your needle valve will then go down that bit far to stop the carb from flooding if you understand what Iam on about, anyway How did the plug far , my one are fine, after 3 years untuoched, now i do hope this may help you get a some fun and a ride in the sun Yours Anna J

Previously robert_tuck wrote:

Hi Anna, You may have a point with the needle valve as i recently changed the old (1960!) nylon needle for a new viton tipped one, Think i'll put the old one back in. The Fuel level appears correct ,although i used a tube from the pilot jet which may not be the best way to test it.I will try injector cleaner on the plug collection, I was thinking caustic soda.With a clean running engine plugs should last for years,but there is something in the fuel now that can coat the insulator in a rich running motor and will not burn off easily.

Hello your missing the point I made, the Needle valve body holder dose not fit right in to the Carburettor body in the correct way , you need to file OFF a 20thou Off the flat were it fits so you have the right float leave ,this is were the problem of rich mixture lies the wrong float leaves !!! This new fuel is hydroshopic , and you need to lower the float leave by 20 thou or more, it dose not matter if you got a new Carburettor , or Not you all need to lower the float leaves now do you all understand !!!

Yours Anna J

What has the hygroscopic propensity of the fuel got to do with the float level ??

And as to filing the carb or it's parts to alter the level that is unforgivable.

If it is a concentric carb you can adjust the position of the brass seat in the ally float bowl, look it up on t'internet and you will find the instructions on how to do it, if it is a monoblocyou can adjust the petrol level by fitting or removing the fibre washers under the inlet fitting this changes the point at which the needle hits the seat.

I suspect sticking Viton tipped needles may be being caused by the ethanol softening the rubber although Viton is supposed to be a wonder material proof against everything, my monoblocshad the same problem and fitting several spares of varying ages solved it

Regards Gromit

Previously anna jeannette Dixon wrote:

Previously robert_tuck wrote:

Hi Anna, You may have a point with the needle valve as i recently changed the old (1960!) nylon needle for a new viton tipped one, Think i'll put the old one back in. The Fuel level appears correct ,although i used a tube from the pilot jet which may not be the best way to test it.I will try injector cleaner on the plug collection, I was thinking caustic soda.With a clean running engine plugs should last for years,but there is something in the fuel now that can coat the insulator in a rich running motor and will not burn off easily.

Hello your missing the point I made, the Needle valve body holder dose not fit right in to the Carburettor body in the correct way , you need to file OFF a 20thou Off the flat were it fits so you have the right float leave ,this is were the problem of rich mixture lies the wrong float leaves !!! This new fuel is hydroshopic , and you need to lower the float leave by 20 thou or more, it dose not matter if you got a new Carburettor , or Not you all need to lower the float leaves now do you all understand !!!

Yours Anna J

I have noticed that the original Monoblok's do not have a washer beneath the fuel bowl valve seat, only the new production ones do. So ifa washeris fitted to an original carburettor, this will raise the fuel level drastically. Incidently, there is no need for a sealing washer at this point as the fuel will never rise anywhere near this height while running.

Also, i have an original Monoblok fitted to a twinwhere the nylon needle had worn (through years of vibration)a smallpocket in the brass float upon where it comes in contact. This allowed the fuel level to rise higher than required. The float was coming in contact with the top cover screw boss, stopping the needle from seating tightly in its seat, allowing the bowl to flood. I remidied this by soldering a tiny piece of brass shim in the depression, and filing flat to original pad height.

I might add, that all my hard starting, stalling, rich running, ETC. over the years hasoftenbeen directly due to fuel levels being too high OR too low.

Robert:

Correct my thinking if I am wrong; If you add weight to the float will it not cause the fuel level to be higher and then the fuel mixture will be richer? In order to close the float needle/valve you will have to have a higher level of fuel in the bowl to counteract the increased displacement.

Conversely, a lighter float will be raised higher.

Just early morning thoughts here in California.

Mike

Previously robert_tuck wrote:

Previously Paul Knapp wrote:

I have noticed that the original Monoblok's do not have a washer beneath the fuel bowl valve seat, only the new production ones do. So ifa washeris fitted to an original carburettor, this will raise the fuel level drastically. Incidently, there is no need for a sealing washer at this point as the fuel will never rise anywhere near this height while running.

Also, i have an original Monoblok fitted to a twinwhere the nylon needle had worn (through years of vibration)a smallpocket in the brass float upon where it comes in contact. This allowed the fuel level to rise higher than required. The float was coming in contact with the top cover screw boss, stopping the needle from seating tightly in its seat, allowing the bowl to flood. I remidied this by soldering a tiny piece of brass shim in the depression, and filing flat to original pad height.

I might add, that all my hard starting, stalling, rich running, ETC. over the years hasoftenbeen directly due to fuel levels being too high OR too low.

Hi paul, I too have a brass float and I have considered soldering it to reduce the fuel level,alternatively it should be posible to turn Anna's 20 thou off the needle body.Still the bike is going well hit 80 in third today ,a vast improvement.

NO I said 20thou or more off flat on the body of the carburetor float blow !!!! , were the needel valve body holder fits can you not read right ! if you lower the needel valve body then your get the float to shut off earlire than it would do so then you lower shut off point and you now that bit less fuel to flood the carburetor, so then you can get the carburetor to run leaner and is inmaterial witch float needel you use nylon or vitron tiped bass they both do the same job the thing you need to control is the fuel shut off point, with the needel valve, this controls the leave of the fuel in the carburetor float blow chamber, so then what have you now learnt one to control the fuel leave and the rate of the fuel leave in the float chamber, or float blow ! Rigth are you all now getting this ! yours Anna J

Previously Paul Knapp wrote:

I have noticed that the original Monoblok's do not have a washer beneath the fuel bowl valve seat, only the new production ones do. So ifa washeris fitted to an original carburettor, this will raise the fuel level drastically. Incidently, there is no need for a sealing washer at this point as the fuel will never rise anywhere near this height while running.

Also, i have an original Monoblok fitted to a twinwhere the nylon needle had worn (through years of vibration)a smallpocket in the brass float upon where it comes in contact. This allowed the fuel level to rise higher than required. The float was coming in contact with the top cover screw boss, stopping the needle from seating tightly in its seat, allowing the bowl to flood. I remidied this by soldering a tiny piece of brass shim in the depression, and filing flat to original pad height.

I might add, that all my hard starting, stalling, rich running, ETC. over the years hasoftenbeen directly due to fuel levels being too high OR too low.

Monobloc is the rigth word Not monoblock ! and this is all twodle there is only one needel valve not two ! with E5 fuels it eats solder like no tomorrow so thats a bad idea what! and E5 fuel eats rubber and some gaskets and eats cork too , check out the FHVC website its all on there, !

WOW!!!...You are correct, it is Monobloc, sorry about my mistake Anna J., I must remember that only a very select minority are allowed to make spelling mistakes here. . ...But I must confess, I don't know what "twodle" is, (not in my English dictionary) ,.....AND,nowhere have Imentioned two float needle valves! If Ethanol mix fuels eat solder, there must be by now, a few brass floats in dire trouble, as the one I have is factorysoldered together. I must confess though, I have never used any Ethanolblend fuels in any of my bikes, only 95RON distillate, so maybe I am just talking twodle,.....err, sorry, TWADDLE.

Paul.

Previously Paul Knapp wrote:

WOW!!!...You are correct, it is Monobloc, sorry about my mistake Anna J., I must remember that only a very select minority are allowed to make spelling mistakes here. . ...But I must confess, I don't know what "twodle" is, (not in my English dictionary) ,.....AND,nowhere have Imentioned two float needle valves! If Ethanol mix fuels eat solder, there must be by now, a few brass floats in dire trouble, as the one I have is factorysoldered together. I must confess though, I have never used any Ethanolblend fuels in any of my bikes, only 95RON distillate, so maybe I am just talking twodle,.....err, sorry, TWADDLE.

Paul.

Hello well (95RON) is made for suger cane and other things like palm cornels and she nuts all these are vegie oils then blended with left over crud oil and wast oils its all distilled to make up (95Ron) diesel is what left after being distilled this is the heavy oils left over, so our old transit van run on rubbish left over from the distilling process , and we end up paying more for it, how that work out, !

and take on notices of me will the spell bit I have a job spelling myself , I must get a new key board , this one puts letters all over the place, any way have fun

yours anna j

Previously robert_tuck wrote:

Hi Anna, Its easy to spout off without thinking.Read my post and THINK!.I agree with what you are saying but have found a better way.The Vincent Boys had the same problem and turned a small nut on the bottom of the needle which lowered the level. I dont (yet) have a problem with eth corrosion as i only run BP ultimate.THe heavy brass viton tipped needle does not seem to work well with a brass float ,I dont think it closes as positively as with the lighter plastic float,all too heavy.After making up my own (rough) 31/2 slide I have 2 spare no3 chrome slides (I new in box) ,anyone got a chrome 31/2 to swap?. I did run eth fuel for a while and even though i ran the fuel out as far as possible the residue has eaten into the bottom of the chamber.We are on borrowed time.

Hello Now try plastic float and Nylon float needel see if that works, were all having problem with carburettors even the modern bikes are having trouble and cars to that cut out with on warning because they get a air lock from the fuel tank then you have a vacume in the fuel lines , and with the monobloc you needed to check the cutway side for movement in the barrel that what is the cause of rich running a worn cutaway barrel were the side fits , you can machine them out and fit bass inside to take up the worn barrel up , or as Martin Bratbury dose he fits the bass around the side cutway and machines out the barrel to fitthe side so there is no side to side movement, just the up and down movement you need, anyway I do hope you get it sorted the summer is slowly running out of time, we have a hard winter this year , shiver your timbers yours Anna J

Previously anna jeannette Dixon wrote:

Previously Paul Knapp wrote:

WOW!!!...You are correct, it is Monobloc, sorry about my mistake Anna J., I must remember that only a very select minority are allowed to make spelling mistakes here. . ...But I must confess, I don't know what "twodle" is, (not in my English dictionary) ,.....AND,nowhere have Imentioned two float needle valves! If Ethanol mix fuels eat solder, there must be by now, a few brass floats in dire trouble, as the one I have is factorysoldered together. I must confess though, I have never used any Ethanolblend fuels in any of my bikes, only 95RON distillate, so maybe I am just talking twodle,.....err, sorry, TWADDLE.

Paul.

Hello well (95RON) is made for suger cane and other things like palm cornels and she nuts all these are vegie oils then blended with left over crud oil and wast oils its all distilled to make up (95Ron) diesel is what left after being distilled this is the heavy oils left over, so our old transit van run on rubbish left over from the distilling process , and we end up paying more for it, how that work out, !

and take on notices of me will the spell bit I have a job spelling myself , I must get a new key board , this one puts letters all over the place, any way have fun

yours anna j

Anna,

Some 95RON Gasoline contains Ethyl Alcohol, which may or may not come from sugar cane. the rest is obtained by the traditional route of distillation of crude oil, hydrocracking etc.

Diesel fuel has always come from a different fraction of the distillation process and is actually more engine and environmentally friendly than in days of yor.

Not wanting to go on about it, but the 95RON available here has no ethanol in it,...(palmcornels? or she(sic) nuts, sugar cane or lawn clippings)...the pumpE10 (94RON) has 10% ethanol.Also, we have available 91RON, 98RON (both non ethanol). And an relatively newly availablepump fuel with 85% ethanol (E85). Only a couple ofbrands handle the 'E' petrols.

I'm with Anna on the keyboard stuff - it biggers yiur speeling. The spear chucker isn't nuch good for finding speeling miskates either! Probably due to the confueion between US and UK keyvords! Gucking pain in the add innit?

Previously lionel_yexley wrote:

I'm with Anna on the keyboard stuff - it biggers yiur speeling. The spear chucker isn't nuch good for finding speeling miskates either! Probably due to the confueion between US and UK keyvords! Gucking pain in the add innit?

Hello Lionel were have you been then ! please tell all you are your useual joyfull self nice to have you back on the NOC web Yours Anna J

Previously robert_tuck wrote:

Now that the industry has geared up to make ethanol (with huge subsidies from the taxpayers) it seems sensible to supply an ethanol based fuel for Vehicles that have been DESIGNED for it. Normal oil based fuel should not be adulterated with Ethanol.The majority of the public are unaware (and don't care) about ethanol issues. If you use a car regularly you will not realise what is happening. The motor industry is not making a big fuss because its supplying new cars to replace those that are too expensive to repair.The repair industry is making money . Those who only use the car very occasionaly and buy cheap supermarket fuel will be having the problems . We are in a similar postion but worse as we expect to keep our bikes not buy a new one in 5 or 6 years and we leave them with old fuel in.If you are feeling smug because you are not having a problem ,get ready for a nasty surprise.Look in the bottom of your float chamber.The real losers are those who's engines conk out in the fast lane on a busy motorway,and daft folk who put car fuel in the outboard motor or even in their light plane/helicopter (no its not supposed to happen is it).

Rob you taken the very words out of my mouth, mate well put, yes the Auto industry is all about making Big Big money out of us Petrolheads , or are we just Sheep Ba ba !! Yours Anna J