Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: Glenzil on October 14, 2016, 05:30:07 PM
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Got the carbs to bits day before yesterday. Took me while as the slides and float pins were completely gummed up and stuck solid. A couple of days soaking in diesel helped a lot! They're now all apart but the bowls are full of toffee-like gum which doesnt bode well for the jets etc, so....I've ordered one of these
https://www.amazon.co.uk/gp/product/B00PJRJYNS/ref=s9_simh_gw_g60_i1_r?ie=UTF8&fpl=fresh&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_s=&pf_rd_r=91315J5EEQ16QZFPANT1&pf_rd_t=36701&pf_rd_p=16f14aeb-bd11-4e9e-8c26-9ca0139074ee&pf_rd_i=desktop
It was only £30 and is probably not spectacular but I just wondered if any one else has tried this type?
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Ashimoto (Ash) is your man for this. He has a test that involves something to do with silver foil? I usually sub it out to someone that knows what they are doing to be honest.
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Very similar to my one.
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Can you post how it performs as I am thinking of doing the same.
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The gum and varnish will dissolve in cellulose thinners. Much cheaper than carb cleaner aerosols but basically the same solvent.
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I suppose for that money you can't go wrong. The test is to put a piece of aluminium foil in the tank and after a couple of minutes of ultrasonic action you should see tiny perforations when you hold it up to the light. Some Chinese small ones are very aggressive though and the foil turns to dust so be careful. I agree that it's best remove all of the old fuel varnish & a good dunk in solvent will remove most of it. Get parts as clean as you can 'mechanically'/chemically then ultrasonically clean. Test the cleaning fluid with a scrap alloy carb part first if you have one to make sure it doesn't discolour the metal or remove the original irridescent finish if you are lucky enough to still have that finish
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I've been soaking the various jets in cellulose thinners and have soaked the rest in diesel for a couple of days to loosen up the crud. As soon as I've had a go with the ultrasonic cleaner ill put up some pictures and let you know what its like.
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I purchased the 6 litre version and have been really pleased with the results.
This pic shows my float bowls at differnt stages of ultrasonic cleaning, i think i was giving them 15 minute blasts in the cleaner and just repeating and wiping them until clean.
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Before these ultrasonic machines were about, we used a old pressure cooker and got good results. Looks like it is doing the job.
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I hadn't thought of using one of those trigger, I'll look out for an old one. My mates mum used to make grey vegetables in one when we were kids ;)
I had to clean some su carbs from a rover 2000, last weekend which had the float chambers half full of petrol tar as they'd sat for 15yrs, boiled the parts in plain water in an old saucepan. It all swelled and came off in about 10 minutes.
Proprietary carb cleaner uses acetone as far as I know, used to be supplied as nail varnish remover amongst other things but used in fibre glass work etc.
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I hadn't thought of using one of those trigger, I'll look out for an old one. My mates mum used to make grey vegetables in one when we were kids ;)
I had to clean some su carbs from a rover 2000, last weekend which had the float chambers half full of petrol tar as they'd sat for 15yrs, boiled the parts in plain water in an old saucepan. It all swelled and came off in about 10 minutes.
Proprietary carb cleaner uses acetone as far as I know, used to be supplied as nail varnish remover amongst other things but used in fibre glass work etc.
One of my fathers day pressies was 5l of acetone off eBay... sad or what :) . I think the banned stuff was a mixture of solvents including Methylene Chloride. Worth a try with std thinners from autojumbles at 5 quid for 5 litres. Pressure cooker sounds like a good idea Trigger. I think combinations of solvents, boiling, blasting & ultrasonics is what the pros' use. Ultrasonic cleaning, on it's own, never seems to work for me and I have access to 4 massive ones where I work and a a 45 litre one of my own
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I hadn't thought of using one of those trigger, I'll look out for an old one. My mates mum used to make grey vegetables in one when we were kids ;)
I had to clean some su carbs from a rover 2000, last weekend which had the float chambers half full of petrol tar as they'd sat for 15yrs, boiled the parts in plain water in an old saucepan. It all swelled and came off in about 10 minutes.
Proprietary carb cleaner uses acetone as far as I know, used to be supplied as nail varnish remover amongst other things but used in fibre glass work etc.
Are you telling me that vegetables are Not grey :) :) :)
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You're not putting the veg in with the carbs (now there's a food joke I nearly didn't spot) are you trigger?
That's a pretty useful father's day present Ash, I'd have been pleased with something like that. My father worked quite a bit with glassfibre, so just grew up with that as one of the background smells.
For years we run an analytical chemistry lab within a factory and everything was steamed to clean it in there. All the vessels and aperatus with whatever was on them were kept clean using that method, including any tarring.
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I've had a go with the cleaner now and tried a variety of home made cleaning fluids including water/fairy liquid, water/morrisons multisurface cleaner, water/dissolved dishwasher tablet. The best result I had was with the dishwasher tablet. I found that a couple of 15min blasts worked well enough to clean the body, it seems to clean the side facing the bottom of the bowl best. I assume this is where the transducer is. Overall its pretty good for the money, its sold as a 2L capacity but its more like 1Ltr. The next one up is 3L which is also more powerful so would probably be better[attachimg=1][attachimg=2]
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I think I will just stick with using the dishwasher or if there really bad boiling them on the hob with a dishwasher tab as its not failed yet.
Mick
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Well I got licorice allsorts for fathers day. 🤔
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yes i did leave the enulsion tub inserted! well spotted. :D I had a go at getting one of them out and it was well and truly stuck, so its a job for another day, but definitely must come out and be cleaned before they go back together.
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You need a bit of 4mm dowel and go in from the top. Place the dowel on the tube and tap it out.
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Tubes are out now - bit of heat and some WD and a thin bit of dowel
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I think I will just stick with using the dishwasher or if there really bad boiling them on the hob with a dishwasher tab as its not failed yet.
Mick
May have to try this!
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You can always clean the dishwasher out afterwards ;)
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If the dishwashers working properly, it'll flush it all out! Most of them are clogged with crap mind..
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I repair commercial dishwashers for a living and I find a lot that are clogged with crap.
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You really need to instruct the owners that dishwashers ain't toilets!!!
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Already done
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Just to add my 3 cents. It is important to make sure thatt he internal passages are clear ESPECIALLY the idle circuit. Below is a description I posted a while ago of how I checked these were clear.
The idle circuit consists of 3 holes and the pilot jet.
hole 1 can be seen on the carb wall on the inlet side throat at 90 degrees from the top before the throttle slide, this actually joins in to the hole from the air screw by the way.
Hole 2 is a VERY small one at the base of the throat on the exhaust side at 180 degrees from the top just in front of the throttle slide. This is where the idle mixture is fed in to the cylinder.
Hole 3 is where the air bleed screw goes in.
At idle air is drawn from hole one and the air screw then adjusts the amount of incoming air, this is then mixed with fuel from the pilot jet To provide the idle mixture.
The resulting mixture then squirts out of the very small hole (hole 2) at the front of the throat in to the cylinder.
I found the best way to check for blockage in the whole pilot circuit is to remove the pilot jet and air screw and blow down the air screw hole and at the same time cover the pilot jet hole and the other 2 holes with some combination of fingers and thumbs. You can then lift a finger or thumb from each hole in turn and hear if you get air blowing through.
It's a bit like mastering playing the bagpipes but an effective way to check the circuit for blockage.
This may sound complicated but if you find the holes and study the plenum chamber in the base of the carb it's pretty obvious how it works.
Hope this helps fellow owners with idle/suspected blocked carb issues.
I must apologise for my lack of foresight in that I should have taken some pics whilst the carbs were off. If I take them off again in the near future I will post pics to show where the relevant holes are.
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I found the best way to check for blockage in the whole pilot circuit is to remove the pilot jet and air screw and blow down the air screw hole and at the same time cover the pilot jet hole and the other 2 holes with some combination of fingers and thumbs. You can then lift a finger or thumb from each hole in turn and hear if you get air blowing through.
It's a bit like mastering playing the bagpipes but an effective way to check the circuit for blockage.
The mental image this has conjoured up has still got me chuckling... ;D
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As I was reading it, my brain was already thinking of bagpipes before you mentioned it. Uncanny, or was it the haggis I had for breakfast?
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Thought i'd add that I ended up basic ally doing the above. I simmered the carb bodies in a Dishwasher Tablet Stock for an hour or so (Missus loved that), then did the bagpipe routine through all the holes to work out what went where.
It seems to have done the job, I was about to send the carbs in for US but I'm inclined not too for the time being, bike now starts and runs.
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8) Saved some cash, then.
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I'll wait until it's running 'well' before feeling in any way smug, lol
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Ok, I didn't get the ultrasonic that is on the first post of this thread, but a very similar 2L version (fleabay) with a heater. It lasted about 30 minutes in two 15 minute stints before the sound and the cleaning action dropped right off. Carried on and finished the carbs on one bike with very slow progress. But have sent it back at my expense. Any similar experiences or recommendations?
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Ok, I didn't get the ultrasonic that is on the first post of this thread, but a very similar 2L version (fleabay) with a heater. It lasted about 30 minutes in two 15 minute stints before the sound and the cleaning action dropped right off. Carried on and finished the carbs on one bike with very slow progress. But have sent it back at my expense. Any similar experiences or recommendations?
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Yes I fixed one from China and the build quality was sh*te bordering on electrically lethal. If you buy a Chinese one, get it via an importer who guarantees that the CE marking is legit.
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Ash, took that onboard. It was marked as "Quality Guaranteed, CE / FCC / ROHS" with copies of certifications on their site. (genuine??) China made, but distributed from UK. They asked me to inspect the main board for them before I finally returned it and it actually looked very neat and good quality.
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Ash, took that onboard. It was marked as "Quality Guaranteed, CE / FCC / ROHS" with copies of certifications on their site. (genuine??) China made, but distributed from UK. They asked me to inspect the main board for them before I finally returned it and it actually looked very neat and good quality.
OK sounds good then . TBH the transistors/IGBT's etc that drive the ultrasonic transducers lead a hard life switching a capacitive load at high powers/frequencies and even the UK made ones have a tendency to go 'pop'. Plus manufacturers are now building in obsolescence by integrating the drive electronics within the microcontroller. If the microcontroller goes defective it's pre-programmed and they won't give you the code to reprogramme a new one or even sell a pre-programmed one. So BEWARE paying a lot for a modern 'Ultrawave' one or other 'high end' types.
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I've nothing like the electronics knowledge of Ash but along a similar vein of low cost manufactures of machinery I've recently worked on a Chinese made chainsaw for somebody.
Speaking to somebody who runs a garden machine repair company, they told me that they won't even offer to work on machines manufactured like this.
So had a good look at it as it was stubbornly a non runner and at first appearance it looks OK and quite well designed. This is really the core of the problem as the design is a straight rip off of a genuine Stihl machine, so they had nothing to do with this part of the process. Even the plastics used are made to mimic the colour and layout of the Stihl.
Getting further into it, the original problem seems to have been the flywheel had never been properly tightened so that during initial use it had been running loose on its taper and rattled the woodruff key almost to nothing. Had to tap (panel beat, peen) the keyway back into shape or the crank was scrap. The jet circuits it the carb had blocked as it hadn't been used recently, so cleaned it all out and set it up to its manual which stated a start point for the idle jet was one and a quarter turns out but would not start. Eventually get to about one eighth of a turn to get it going but any linearity of the screw is absolutely minute with almost breathing on it to give you a run or stop setting. Looks like the taper on the needle valve and seat are just too course to give any sensible response.
The upshot of it is that it does go and work as a chainsaw but looks more impressive than it functions.
In addition, the plastic casings are clamped by torx screws that you can't really tighten as no ferrules are fitted to prevent the plastic being squashed even on high load casings like the pull start / recoil unit. The metal on important fixings is only just sufficient to withstand the load required to keep parts in place and the clutch drive for the chain is made with such a poor tolerance (if at all having any checks applied during manufacture) that it will not run concentrically, making the chain tension vary wildly.
The instructions claim compliance with euro laws etc and I know the price point is very different from quality brands but really its not going to function for long as a chainsaw from what I can see.
Bit of a rant really but I think it illustrates for me how nicking a good design from someone who has spent the cash on R&D and long term testing, then produced it with substandard materials and methods can end up with something not really fit for purpose, however it's dressed up.
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Think I just bougt the same model of chainsaw. First pull, the cord return mechanism packed in!! Now sorted and does what a chainsaw does but just fear its a handgrenade waiting to explode. Knew i was buying cheap but just thought as it wouldn't get much use, it would be ok.
When you look at the piss poor design of the cord recoil, you think - what more cost would it be to design it properly from the outset? Such a simple function that's been about for years.
You pays your money etc...