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Why aren't I more technically minded?


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Guest Mr Miller
Posted

If you can cast your collective mind back to this..........


http://www.themotorbikeforum.co.uk/view ... =5&t=22975


Well I have an update.....


Tonight I went to my parent's to fit new mirrors, start her up, maybe take her out for a spin to reacquaint myslef with her before the Smash & Grab ride on Sunday.......


Remaining mirror off, new mirrors on and adjusted, wheel her outside - 'kin hell! she feels heavy! Front boot's a bit low on psi, so start her up and let her idle for about a minute, nip into get tyre gague, get pump from car - all this takes less than a minute - kneel down at front wheel, remove valve cap and......phew! she's a bit petrol fume-y, glance up and feck me, there's two puddles of petrol under her! One from the breather tube as before and the other from parts unknown!


After investigating further, the other leak seems to be coming from a small tube or nozzle from within the carb assembly. I have taken some photos but they are on my phone and are a bit shonky - I'll get some more tomorrow with the proper camera!


Now, one possible cause of this (and it's the only one me & me dad can come up with....he's a woodworker, I'm a numpty!) - one of the downpipes didn't get anywhere near as warm as the other three...and it is the one 'opposite' the leaky nozzle!


If this cylinder isn't firing, the petrol will still be being drawn into it by the piston - on the exhaust stroke, where would this unburnt petrol go? Would it come out of this nozzle or be routed out through one of the breather tubes?


If the above is sound, would this non-firing cylinder be caused by the spark plug? How do I tell if said plug is kaput?



I know I'm setting myself up for a ribbing...but I miss riding my bike and all this will go toward me getting a better understanding of how she works and more importantly, how to fix her!


All help much appreciated.............and I'll take all ribbing in a light-hearted way!


Thanks in advance,


Mr. M.

Posted

first of all how is the bike running ? is it running as normal ? or sounding rough ?


if its rough then it could be running on three cylinders


secondly for the leak it sounds like one of the floats in the carb has stuck open allowing the carb to overflow which is where the fuel is coming from (the overflow)


thirdly if you was a bit closer you could have got it to me and i could have stripped it down and probably sorted it in a few hours!!! :?

Posted

oh also the unburnt fuel will come out of the exhaust and ignite and burn away


the only real give away of it running on one less cylinder/missfiring is listening to it and pulling the plugs


some bikes run hotter on the two center pots then on the two outer due to the outer having more surface area closer to cooler air but they are fueled for this to compensate :)

Guest Mr Miller
Posted

To be honest, she did sound a bit rough but I put this down to maybe being caused by her being stood for a while and being cold.


Are you saying that I could have a stuck carb float AND only 3 firing cylinders or that the stuck float is causing her to only run on 3 cyls?


.......and I'm sorry for choosing to live up here, where I've spent 35 of my 37 years!


You could always stop off for a break on the run on Sunday! Strap you tool kit to the back of your TL! :wink:

Guest Mr Miller
Posted

As you look at her from the front, it's the far right hand side downpipe that stays cool enough to put your hand on - the other three, you couldn't bear to dab your finger on!


Wouldn't there be some evidence of unburnt fuel getting into the exhaust?

Posted

an overflowing carb doesnt mean it will run rough it can run ok as the cylinder will only use what it needs


the float works by letting a certain amount of fuel in then stopping the flow till the level drops then opens up again


think of it like a toilet!!!! the cistern allows so much water in till the ball cock stops the flow if you hold the ball cock down then the excess runs out your overflow


if you can reach the carbs tap them lightly with the end of a screwdriver this is usually enough to release the stuck float

 

You could always stop off for a break on the run on Sunday! Strap you tool kit to the back of your TL! :wink:

 


you have seen the size of my tool chest!!!! :lol:

Posted
As you look at her from the front, it's the far right hand side downpipe that stays cool enough to put your hand on - the other three, you couldn't bear to dab your finger on!


Wouldn't there be some evidence of unburnt fuel getting into the exhaust?

 


well i would certainly say its running on three then :lol:


is it the same carb thats leaking do you know ? or is there just one overflow pipe that all the carbs connect to :?

Guest Mr Miller
Posted

http://img38.imageshack.us/img38/9303/carbs1.jpg


Where the arrow points at the carb assembly (No. 11), that's where the nozzle is. It looks like there is at least one more overflow but I need to get you a better pic of it!


I could certainly try tapping them with a screwdriver - no harm, eh?

Posted

sounds like there is two overflows then one for two carbs


yeah cant do no harm giving it a little tap the float bowl is at the bottom of the car there should be some drain screws on the bottom of each one


if it does free it they will still need a strip and clean at some point


but its still not explaining why its running on 3 cylinders!!! No1 carb could just be gummed up or even blocked with something which is blocking the jets and making the float stick!!

Guest Mr Miller
Posted

So could it be something as simple as a knackered spark plug that's causing her to run on only 3?


What's the next few possibilities?

Posted
What's the next few possibilities?

 


i wouldnt start digging too deep just yet i recon it is just a fueling issue :)

Guest Mr Miller
Posted

Ok boss!


Stripping, cleaning & reassembling - if all goes according to plan, how long would that take?


Don't laugh - checking for kaput spark plugs - how's best in your experience? Putting a new one in? Swapping it with another one of the other 3 pots that do get hot?

Posted

for me stripping cleaning reasemble about 3-4 hours taking my time and getting everything spotless


that would be all the carbs though and all the float hights set too plus balanced up and plugs pulled cleaned and re gapped :)


if i suspect plugs i just pull them and change them :lol:


the only real way to check a plug is to pull it out put it in the plug lead and hold it against the engine and turn it over watching for a spark but use insulated pliers to hold it!!! although it is fun to watch others get a shock :lol:

Guest Mr Miller
Posted

Hmmmm?! Mucho pounds at a mechanic's then?


Damn myself for choosing chemicals rather than engines at college!


Oh, I see Frankie is giving me grief for missing out on the ride!.........cheeky short-ärse! Thanks for the sympathy!



Just found out that Mrs. M's school reunion isn't going to take up all of Saturday as expected. Might be able to get the bike to the doctors in the morning after all!

Posted

to be fair a mechanic will do it a lot quicker id say an hour and half tops


i take my time and strip everything and check alsorts whilst im in the area plus balancing can take a fair bit of time


a mechanic will probably charge a set amount for that and for them time is money so will just do the job and get out if you like!!!

Posted

my mate blew the engine on his RS50 (no surprize there) and the mechanic charged like 70 pound labour charges for stripping it down giving it a quick once over and putting in a new piston. its worth it, if your not 100% about what it should be like you might overlook something simple and could maybe do some serious damage

Posted

Sorry Mr M, thought you had this in the bag and was stalling just for mirrors.. :mrgreen:

Guest Mr Miller
Posted

Cheeky bleeder!


I was looking forward to this ride-out very much!


To be fair, I quite like the look of the round mirrors now they're on her!


I may see if the instructor I used would like to quote me for the work needed on the bike?!? Hmmmmmmm? - we'll see!


You guys have fun without me and organise the next one when I'm & running with no problems!


Ride safe guys!


Mr. M.



P.S. Let me know when you're setting off from Ripon and I'll wave to you as you pass through Bedale!


:wave:

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