Just asking the question... what is the current thinking on getting injectors clean? Do I put a bottle of magic stuff into the tank and run it through or is that just wasting money. Should the injectors be taken out and professionally cleaned. The old basic bike does the round town duty and also spends a fair bit of time sitting at home. I also use lead additive in the fuel as the bike was built in 1983 and not prepared for unleaded.

I put about 2 tanks of gas through mine every week - seems to do the trick. Once in a blue moon though, I do add a slug of injector cleaner to a full tank, but I'm not convinced that it makes much difference really.

As usual, I read these posts and it sows the seed of "perhaps I should do that" - but a combination of laziness and "if it ain't broke-ism" usually saves my bikes from unnecessary intrusion. Trouble is, I've got an ultrasonic bath and I love any excuse to play with the toys...so it is probably only a matter of time before I succumb!

"Professionally cleaned" - hmmm define professional? 

I shall watch for replies with interest...and maybe just go and order a few o-rings etc. , just in case....

If the engine is running fine then don't bother with injector cleaner. If you think that it might make a difference then it probably won't.
As for the lead thing, that is a scare story that has been going around for quite a while now. Just use the normal unleaded fuel and check your valve clearances every 15,000 miles or so. I'll bet that you will not see much change in those clearances. If they start reducing after 150,000 miles then you know that your valve seats are wearing, but you will still have another 150,000 miles before you need to take the head off and have hardened valve seats fitted at a local machine shop. Should you still have the bike at that stage then the few hundred quid that you spend on valve seats will be much cheaper than the thousands that you would have spent on lead substitute - which might not be doing anything anyway.
If you just want to spend money for the sake of it then buy a new helmet.

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Opinions vary, so take your pick!

In Oz, 95 and 98 fuel are to some extent self cleaning. If the injectors are seriously gunked up, professional off-bike is the way to go, as any additive won't do it nearly as well, if at all. For a machine doing some sitting unused time, some recommend a fuel additive that claims to stop the fuel going off. Opinions vary quite strongly whether these are any good. I've never used one, even in the boat which is often not used over the colder times. 

If you do use an additive, my preference is to use it at a higher concentration than recommended. Add the concentrate when your fuel warning comes on, or you suspect it is about to. (Your warning light works, right? ) run it on that for as long as you dare, or carry spare fuel for when it runs out. (This view picked up in a professional mechanic seminar on fuel injection.)

Best of luck. 

Bill

I'm an additive guy. It probably has a placebo effect...the bike "seems" to run better but it's subjective.

I run the injector cleaner through the fuel tank probably twice a year.

It's good for the economy.

It keeps people employed.

I like the colourful charts and graphs that always accompany the advertising.

No, I do not want to buy a bridge...

At the moment the economy has dropped off dramatically....now about 10 litres to 130km. I changed the plugs yesterday, tested the bike...all OK. Went for a longer ride on a country road this morning and I ended up with a K75. Yep, one plug lead had rattled itself off, side of the road repair.
One area eliminated from concern, now the fuel. I will probably try the cheapest road first...the cleaner and then if that does not work take the injectors out. Yes Paul, O rings will be on the shopping list. Like you, if it aint broke, no need to go further.

When I got my current K 100 I believed it was not as quick as my first K 100.. Although there was four years between ownership, I was convinced It needed my attention.

Not having had the benefit of  being on the forum at that time, and not wanting to get my hands dirty yet, Injector cleaner came to mind and was added, albeit on a full tank, and away I went. 

Placebo effect perhaps, but I was convinced over time,  the bike ran better.

I then began to notice the idle speed wandering so I began to suspect the performance might be affected by something else....really ????

First... read the forums for advice.

Second.... check everything that may affect performance.......

I cured a small air leak, balanced throttles, changed number 4 plug lead,  everything else was good.

I get 200 motorway miles before the reserve light comes on .

Idle speed  is smooth and steady at 1000 revs.

Part of me still believes the fuel additive gave me an improvement, but setting the bike up as it should be helped much more.....

The injectors are 27 years old, can they still perform as when new ? 

We all replace brake and fuel lines for that reason, why not the injectors, if only to remove a possible failure at some point.  Predictive maintenance ? 

 I will remove them and have them Professionally cleaned , I do not possess  a supersonic bath like Born Again Eccentric, and see if it makes any difference when I connect my balance tubes.

Bob

I got a quote from a local firm to look at the injectors. They flow test them first and if they need refurbishment then it will be a total of $32 AUS each. It may be worth it, after all the bike has done just over 400,000kms....just run in!

ainsjac wrote:I got a quote from a local firm to look at the injectors. They flow test them first and if they need refurbishment then it will be a total of $32 AUS each. It may be worth it, after all the bike has done just over 400,000kms....just run in!

How much fuel can you buy for $128? Petrol is a solvent so will dissolve most things. If you are expecting more than 0.5% improvement after the work then you will be disappointed. It may go a little better with the weight of your wallet $128 lighter though.
Don't disturb it if it is working!

For what its worth when I got the 84 K100RT it felt very lively compared to my 92 K100LT and was also lighter on petrol and consistently 10-12+ miles per litre on motorway speeds.

Earlier this year I suffered a sudden increase in petrol consumption on the RT that it now seems about 8 miles per litre. Plugs NGK D8EA, air filter, all look good. I know the plugs should be D7EA but hard to get here and I don't think it makes much difference as the LT also had them in it. Since I now see injector repair kits and seals for very small money as in about €15 I figure it's worth going at them. I bought acetone to use but never did.

Or, should I take up drinking Guinness?

92KK 84WW Olaf wrote:I know the plugs should be D7EA but hard to get here and I don't think it makes much difference as the LT also had them in it.
Or, should I take up drinking Guinness?

Olaf, if you want me to get some D7EAs and bring them with me when I come over for the Christmas brunch, just let me know.

Drinking Guinness is always a good option though. It's good for you - apparently.

S'pose you'll be bringing puddings back too.....

My Guinness consumption is rising. I use it when I am cooking, sometimes if goes in the food.....or stew or puddings.

I need to get making some soon, there's a very nice and hospitable gentleman down in France awaiting a delivery.

92KK 84WW Olaf wrote:S'pose you'll be bringing puddings back too.....

My Guinness consumption is rising. I use it when I am cooking, sometimes if goes in the food.....or stew or puddings.

Well, only if there is a surplus...after all I am an international pudding courier!

My Guinness consumption is rising too. I use it when I am cooking, sometimes it goes in the food....but mostly it goes straight into me!

How about cleaning the injectors with Guinness , we can test this on Paul's bike when he is over in Ireland after Xmas.

In all seriousness I have now fitted replacement injector kits to 5 K's.

To me it was well worth doing this as at least I know all the injector parts are now good and any issues are not injector related.

I struggled with one k100 16V with what I thought was a bad injector but turned out to be a broken wire in the injector loom.

There are plenty of videos's on YouTube showing how to do this but it is not difficult.

I will have to suggest these alternate lubricants for cleaning injectors to the blokes here. I do know they use different lubricants on Friday afternoons... no doubt to clear their own injectors.

Hi,

I thought I'd add to this question. I have a sticky injector, I had to pull a spare off a bike which is not running as a fix but I need a full set on the other bike which I hope to get running again.  So currently I have an injector which needs help.

It does kinda work but it tends to squirt rather than give a fine dispersed aerosol.

I poked about in the top end and there was some fine very black gunk. I'm guessing this is destroyed rubber from fuel pump shock absorber which suffering from old age and fuel pollution ( fermented corn derivatives ). It's extremely fine so it must have got past the filter in the tank.

I gave it 1.5h in an ultrasonic cleaner ( slightly soapy water ) but found this mess afterwards, so not too effective on that front. The cleaner did not improve the jet.

I'm wondering whether there are any techniques like hitting it with a variety of frequencies from a square wave generator to give it a shakedown. and maybe forcing air or fuel back through it whilst doing this. AFAIK they are sealed units so nothing to really service or replace.Maybe just hold it on and back feed it with fuel or acetone.

I suspect that the some of the same fine black gunk has made it past the last line of defence and got into the injector itself, ( or just old age mechanical failure ).

Any thought's / experience on this kind of thing?

I use a 12v transformer, must be AC, to pulse the injectors and then spray carb cleaner through them. 

I found the top off one of those sealant tubes fits over the injector and then inserted the tube from the carb cleaner into it.

Make sure injector is pulsing then spray carb cleaner.

Alternatively as you are in Cork you could try Murphys :-)

first remove and replace the fine filter built into the top of the injector ....there are methods explained in the forum from a few contributors

carbi cleaner often works to dissolve a fair bit of gunk ...use before and after replacing the filter

beware after ultrasonic and carbi cleaner useage the pintle may become stuck if not used for a fair bit of time .there are lubricants available for this

good luck

Thanks Charlie

I forgot to mention replacing the parts

https://mrinjectoruk.co.uk/Fuel-injector-service-kit-Bosch-0280150-seals-filters-our-seal-kit-4-P303035.aspx

https://www.ebay.co.uk/itm/12V-UNIVERSAL-FUEL-INJECTOR-PRESSURE-TESTER-LED-DISPLAY-DIAGNOSE-SYSTEM-PROBLEMS/182839499792?epid=1207788316&hash=item2a92155c10:g:TT8AAOSw5VtZ526D

I got one of these from oohbay (where else) and I find it really handy - it'll do long & short pulse bursts and stuff and you can use it to fire the injectors onto paper towel and compare the size of the damp circles. My simple level of tech - a real shed solution.

+1 on the injector test unit. After removing the filter screens soaking in acrylic thinners will sometimes clear a really stubborn injector. I was told this by a local workshop. WARNING don't smoke or make any form of sparks while doing this.
Reagards Martin.

A tin of carb cleaner and one of these https://www.ebay.com.au/itm/Car-Vehicle-Fuel-Injector-Flush-Cleaner-Adapter-Cleaning-Tool-Nozzle-DIY-Kit/263119972822?epid=2155078363&hash=item3d432c29d6:g:zUAAAOSwOEZZgHtH and it good to go.
Don't leave it connected for very long (10 seconds max) or the injector coil can easily overheat.
I have been doing it for years.