Date: 28-03-24  Time: 08:09 am

Author Topic: Carb clean  (Read 1758 times)

SpiceWeasel

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Carb clean
« on: 29 June 2022, 11:01:56 pm »
Hi all, long time lurker. Just thought I would say hello and show you some dirty photos  :lol
I went to start the old girl up the other week as last time she wasn't to happy so I put this down to old fuel in the tank, not used it in a year but had a few starts and left running. Put some new petrol in the tank and long story short petrol was leaking down the stand. Would only run on 3 briefly if you tried to start with a bit of throttle.
So I managed to get the carbs off today as I reckon one of the floats is stuck. First thing I found was one of the breather/fuel return pipes on underside of the tank is blocked with crusty rubbish...also a bit in the hose. Other side is clear. Then when moving the air box back there was still some petrol in there and the K&N filter stunk of petrol. So got that out and give that a clean as well.
Getting the carbs off was "fun" but got there in the end, I think putting them back might be more tricky. Anyway as I had been breathing in petrol fumes all afternoon I just had a quick look at two of the carbs....well gunked up and float was stuck on drivers side. Nearside float moved but was sticky. Looks to be long overdue a good clean looking at the state of the internals.
I put a few photos up so you can see.

Just wondering who you use for spares? Dealers... can be expensive. Just found Yamparts and Wemoto after aquick google, good prices but not OEM bits generally.
The dirty photos  :lol






Trebus

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Re: Carb clean
« Reply #1 on: 30 June 2022, 02:07:36 pm »
Water in the fuel by the looks, almost certainly as a consequence of ethanol absorbing H2O.

Normal recommended action is to replace o-rings but leave the original float valves unless they’re knackered. Clean up and back together.

FazThou

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Re: Carb clean
« Reply #2 on: 30 June 2022, 08:29:05 pm »
I just ordered these for mine along with new oil and filter and new spark plugs so hoping to give the old girl a bit of a freshen up very soon
4 X Yamaha FZS1000 FZ1 2001-2005 Carb Carburettor Repair Kit + Diaphragm | eBay

SpiceWeasel

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Re: Carb clean
« Reply #3 on: 02 July 2022, 10:41:54 am »
Thank for replies :)
Just quick update: No wonder the old girl wasn't happy looking at the state of the carbs.

Took the carbs apart and everything was completely covered in green gunk and that hard to shift varnish type substance. The jets were mostly blocked, gave everything a good clean with carb cleaner then took it to my parents next door neighbour to put the bits from float bowl and jet needle side etc in his ultrasonic cleaner. We did this one carb at a time so not to mix up parts. Not sure how but managed to lose the small spring that goes on top of the jet needle. Can't find spares so had to rob a spring from a biro pen and cut down to size, it only holds the needle in place so it doesn't move.
After ultrasonic cleaning everything had a good gong over with carb cleaner and a toothbrush, and the jets were cleaned out with proper jet cleaning files.... different diameter metal rods. Amazing how much green gunge came out the little holes. The carbs were cleaned with some "gunk" and a toothbrush then had a good going over with carb cleaner.

Just ordered some new float bowl gaskets and a fuel filter so all the bits are in seperate labelled up tubs. My dad had the other seals, good job as they were knackered as well. Rock hard and starting to split. Hopefully once it all goes back together and I clean the tank breather hole out it should run alot better. I don't have a carb balancer so will have to see how it is after, might have to go to the bike shop for that if needed. I know you can buy cheap balancers but not sure if they are very accurate.
Next door neighbour who fixes up lawnmowers and anything with an engine said he has never had so many issues with carbs since they went to ethanol mix fuel. He basically said if you use standrad fuel then use a fuel treatment with every tank, and if not going to be running for more than a month or two put high octane petrol in the tank first. I think Esso go faster juice is supposed to have no/minimal ethanol in it.



Trebus

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Re: Carb clean
« Reply #4 on: 02 July 2022, 11:20:12 am »
Good job. Just be aware, if you changed the o-rings then unless they are Viton material they will likely be destroyed by the ethanol unfortunately.

SpiceWeasel

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Re: Carb clean
« Reply #5 on: 02 July 2022, 12:50:46 pm »
Trebus, thanks but the acid test will be if it runs after putting it all back together  :lol Yes the o-rings come in a box with different sizes and are supposed to be safe with Ethanol.
EDIT: This is the kit I ordered off ebay (seller was carbtec), has a few more seals in it and not much more than buying just float bowl gaskets. Also got myself one of those valve/jet cleaning tools as well.
« Last Edit: 02 July 2022, 01:22:13 pm by SpiceWeasel »

SpiceWeasel

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Re: Carb clean
« Reply #6 on: 10 July 2022, 07:37:11 pm »
So the carbs are all cleaned out and back together again. Good job I ordered that O-ring kit as my Dad checked his order for his ones and they are not Viton, just standard Nytrile. The old ones were absolutely knackered, rock hard and some fell to bits when taking them off to replace. No surprise really as they are at least 24 years old.

We just replaced the O-rings inside the carbs and new float bowl gaskets. The jet cleaning tool and brushes came in handy, I was very carefull to try and not enlarge the holes in the jets etc.... got a good amount of green gunk out even after carb cleaner and ultrasonic cleaning from the little jet holes. A toothbrush came in very handy as well as you can clean everything without damage.

We checked the float heights, all seem to be the same height and parallel with the carb body when just resting on the little float dodahs. Left them well alone as didn't want to make it worse, hopefully they will be ok. Bike has only done about 18K ish.
This afternoon I cleaned out the blocked hole on the bottom of the fuel tank, was blocked with crusty gunk. Does anyone know if one of the tubes is a breather and one is overflow from tank? I had the tank leaned on it's side with fuel tap to the right, and a little bit of fuel came out of the bottom tube.
I have a little bit of new and old fuel still in the tank so I wacked some Redex in there and was giving it a good shake around, can't see any rust through the fuel filler cap. I will chuck this out before fitting and put some fresh petrol in.

Also fitted a new fuel filter and I have a new upgraded front sprocket nut, never checked it but for a few £ I will just swap it anyway.

Will probably have to wait until next weekend to put the old girl back together again and see if she comes back to life. I don't have carb balancers so I will probably have to take her to a shop to get set up. Could probably do with a new chain kit as well tbh, I think it's still the original but it got a bit rusty in the garage the other year. Also need to bleed the brakes....and whatever other jobs come up  :lol


unfazed

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Re: Carb clean
« Reply #7 on: 11 July 2022, 10:55:53 am »
The same thing happened to me when I was doing the Carbs of a 1973 Honda 350 Four, the O Rings were in bits, but the rubber item in the kit I bought were feck all good on the present day fuel. Even the hoses they supplied were crap. Had to do it all again 2 months later. Lost money on that job and trying to explain to the owner was nearly impossible. Emailed the suppliers of the kit ad got no satisfaction. Owner was none to pleased. Ever since I source the correct seals locally and use an OEM float bowel gasket. Many bearings suppliers also do O Rings but luckily I have a dedicated seal supplier within 12 miles of
my house.
How did you check the float levels, did you just turn the carbs upside down?
« Last Edit: 11 July 2022, 12:05:44 pm by unfazed »

FazThou

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Re: Carb clean
« Reply #8 on: 12 July 2022, 04:32:04 pm »
Did mine and once all back together and primed it started up traight away  :lol


The kit i bought had new float needle valves which meant i had to reset the float heights
Going by the manual i turned them upside down and got a measurement of 12.5-13.5mm from carb body to top of float
Been using it the last two days and is alot better
Could do with checking the carbs for balancing but will prob do that the weekend

Frasier

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Re: Carb clean
« Reply #9 on: 13 July 2022, 07:42:49 am »
I'm in the process of a complete rebuild of the bike, and just finished the carbs. It looked very similar like on the previous photos, green residue, etc. My method: complete disassembly, ultrasonic cleaning, replacing all of the gaskets, assembly. The ethanol fuel makes the brass parts pitted, and must be replaced - the jets at least. Found a great source of real viton gaskets long time ago: Litetek. It is a thai company - who thought that the best gaskets will be made in in Thailand?! All in all, I bought gasket kits from them throught the years for my YZF750R, TRX850, TT600R, and now the FZS600, and everything was perfect. I recommend them.For me it doesn't make sense to buy the OEM gaskets - they are not viton, cannot handle the ethanol. And expensive. Similarly, most of the other sellers (Ebay or moto parts shops) offer chinese gaskets, which are also not viton, under different brand names, or unbranded.To prevent the degradation on my freshly rebuilt carbs I never buy "cheap" 95 fuel, it contains 10% ethanol nowadays, instead 100 octane premium which has 5% ETBE (it doesn't absorb water like ethanol). Alternatively, if you are cost sensitive, you can put a little engine oil or 2stroke oil in your tank when filling up with cheaper petrol at the gas station, it will coat the fuel system with a thin oily layer, and provide some protection. And you can feel nostalgic, if rode 2strokes back in the day...
« Last Edit: 13 July 2022, 07:43:24 am by Frasier »

SpiceWeasel

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Re: Carb clean
« Reply #10 on: 15 July 2022, 10:42:23 pm »
Unfazed: Yes just turned the carbs upside down and tilted until they just rested on the float valve dodahs. We measured about 12-13mm ish, all were the same height as each other and I would say parallel with the carb housing (the flat part of the floats). Just replaced the O-rings (jets, needle etc) and float bowl gaskets. All the bits looked in very good condition after cleaning the gunk off, just O-rings etc were knackered. My bike has only done around 18k miles, had her for the last 20 years.
I got my kit from a seller called "carbtec" off ebay, supposedly viton. Has loads of kits on the shop for all sorts of bikes and reviews are good. Can be hard to get OEM bits now as some stuff they don't make anymore. I did see quite a few sellers which didn't metion what they were made of, so gave them a wide berth. Also some reviews which said the parts were the wrong size...probably the cheap Chinese stuff.

I will def not be leaving 95 fuel in over the winter. This new Ethanol fuel is terrible stuff, best avoided if possible. Wonder if the fuel injected bikes have this issue as well, should imagine a blocked injector would be costly to clean or replace.



unfazed

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Re: Carb clean
« Reply #11 on: 16 July 2022, 01:36:40 am »
I usually bench check them also with a clear tube attached to the drain. Made up a frame for it and it allows the carbs to sit at the same angle as the are on the bike

SpiceWeasel

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Re: Carb clean
« Reply #12 on: 14 August 2022, 09:14:29 pm »
Just an update, finally managed to get the carbs back on the bike (been really busy for the last month).
Turned on the ignition and the fuel pump ticked for a good few seconds while it filled everything up, then stopped as it should. So better than it was before stripping and cleaning the carbs out, fuel pump would just constantly run as one of the floats was stuck with gunk.
Could smell petrol so didn't try and start it. Had a quick check/look and I have a fuel leak, looks to be coming from between carb 3&4 (TPS sensor end) and higher than the float bowls. Now wondering if it's leaking from one of the fuel link pipes between the carbs, do these have O-rings between the metal fuel pipes?

Left the carbs complete and just cleaned the guts of each carb and replaced the O-rings and float bowl gaskets. So a bit unsure where it's coming from exactly.
Looks like the carbs will be coming off again. Is it possible to pull the carbs out and hook it up to the fuel tank pipe? It leaks when you switch on the ignition and the fuel pump pressurises. Would make it a lot easier to find the leak.
EDIT: It's not leaking from the overflow pipe, which it was doing before stripping and cleaning out the carbs.
« Last Edit: 14 August 2022, 09:16:12 pm by SpiceWeasel »

unfazed

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Re: Carb clean
« Reply #13 on: 15 August 2022, 12:01:50 am »
Sounds like as you say the link pipe is leaking, which usually means the O rings need to be replaced.
O ring size is 9.91mm OD x 1.78mm Cross Section (BS 803 V) and are the same as the FZS1000.

The plastic T piece between 2&3 has different size O rings, but not sure of their size
« Last Edit: 15 August 2022, 12:38:11 am by unfazed »

SpiceWeasel

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Re: Carb clean
« Reply #14 on: 15 August 2022, 09:22:57 pm »
Thanks unfazed :)
I still have 2x fuel T piece rubbers from my kit (3EN-14997-00), for the main fuel inlet (2&3).
Also 4x choke plunger o-rings. Never fitted them as didn't want to split the carbs.
Do I need 8x of those O rings for the fuel link pipes? Hard to tell from the service manual or Haynes manual as I think the diagrams are a bit "rubbish". I did find some from (Bearing Shop UK).... BS 803 V.
Looks like there might be 4x O-rings for the coolant T pieces as well, something else to look for.
Is there anything else I need to replace? If I split the carbs I might as well replace all the O-rings, don't want to take it apart for a 3rd time :D

 
 

unfazed

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Re: Carb clean
« Reply #15 on: 16 August 2022, 12:28:19 am »
There are no O-Rings on the coolant pipes just hoses with spring clips and they don't normally leak unless the have been damaged by removal and/or refitting. As far as I know the centre hose between 2 & 3 is no longer available new.

I think it is only 4 you need but I have not stripped the 600 carbs with some time, I know the 1000 definitely has 8 as I stripped a set recently, but since they are so cheap buy the 8 and if you don need them it would not be a big loss. If they are available in the local bearing shop I would buy 4 and go back for 4 more if necessary


Strangely enough, I have never replaced  choke plunger O-Rings on any bike over the years

SpiceWeasel

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Re: Carb clean
« Reply #16 on: 16 August 2022, 06:39:35 pm »
Thank you unfazed  :thumbup
I know the coolant pipes clip on with spring clips, was wondering if there are any more O-rings apart from the fuel connecting pipes. If I am splitting the carbs apart from each other I may as well replace everything O-ring wise.
Also had a quick Google search and there are a couple of bearing suppliers local to me as well, so I can give them a try.