Has anyone experience of syncing the injectors? I have used my Morgan Carbtune on bikes with carbs in the past with good results but having problems with the K100. The Carbtune is well recommended AND its made in Belfast but available worldwide. Morgan Carbtune
Thought that the engine could do with a tune up as it sounded a bit rough at tickover (someone said they all do!) and to try to cure a very slight hesitation from tick over. Bit irritating in traffic.
When I put the Carbtune on they were a bit out but I couldn't get them anywhere near level without some extreme adjustment. i.e. one air screw almost fully in and one on its last thread before it fell out.
Checked all the hoses for leaks or cracks and all appeared ok. Checked the inlet manifolds for air leaks by spraying them with contact cleaner while running. They were ok too.
Had to put the air screws back to where they where. Tickover is just under 1000 rpm which is within spec but can't be adjusted any lower.
Couple of theories on the problem.
Can the co2 settings on the air volume meter affect the injector syncing?
I know that in the olden days, when syncing SOHC Hondas(sorry), it was advisable to adjust the valve clearances before doing the carbs and was wondering if that could be my problem.
The engine has 26,000 miles on it and doubt if the valve clearances have ever been checked. I haven't had it for all of the 26,000 miles, by the way. Just keep putting off checking them since I got it at 18k.
Any ideas before I start tweaking the linkages? I'm getting desperate!

K100 Idling

I don't know if the above link makes things any clearer.

I have also heard, but not tried, either cleaning the injectors or replacing them improves off idle throttle response and overall performance and is on "my list".

Regards,

Phil

To clean the injectors try adding Techron to the fuel for a few tankfuls or Redline fuel treatment the same. Many reports of improvements on the car lists by doing this. BMW sell a car fuel injector cleaner which is well respected.
Regards,
K-BIKE

if after using a cleaner one were to observe the spray pattern of each injector if the cone shapes of the fuel vary
i would replace the injectors
mine varied and i did with the ford injecter suggested in another groups tec pages and voila
my norton vibrated
like an electric motor
someone said"riding a black and decker" i can see that
its so smooth
im a newbe and still am dazzled by it after 4 yrs

i just read the first thread
i would say you have intake leaks
if the compression is good and relativly equal

Hi Comberjohn,
Re-reading your post as suggested by red green I think he is on the money here, you mentioned checking with contact cleaner can you tell me what is in the contact cleaner? Generally if you want to spray a liquid I would recommend the highly flammable carb body cleaner (just make sure the warn you about flammability just in case somewhere around the world they are supplying carb cleaner that is not flammable), some use WD40.

The other thing to use is butane or propane sprayed with an unlit gas torch squirting the gas out. It always seemed to me the benefit of using a gas is that if by some nasty chance it ignites there is a flash and it's gone but if the liquid one has been spraying ignites one has burning liquid on the bike around lots of wires and parts.

So what I am saying to be really sure it is not leaking, give a really careful check with either the flammable liquid or the gas. On my wife's Volvo we had lots of air leaks around the injectors as they are held in there with o-rings which are well known for getting rock hard and then leaking and boy they had done that all right!
Regards,
K-BIKE

Hi everybody. Thanks for the responses.
I think I may have given the wrong idea about the contact cleaner. I had already thought of air leaks where the manifolds are bolted to the cylinder head Someone had suggested that if I sprayed contact cleaner or something similar around the manifolds while the engine was running and the Carbtune was connected, this would temporally prevent any air leaks and prove that this was the problem. Seemed like a good idea at the time.
Tried it and it means that either there isn't an air leak there or it was a stupid idea after all.
I have already tried using injector cleaners that you put into the tank so I'm starting to favour the air leak idea again. Think I will have to remove the injectors and change the manifold seals to be on the safe side. The LT is 20 years old this year and I believe that this is not an unheard of problem. Maybe I should check the injectors and their O rings first.
I tried to remove them before but was afraid to force them in case I did any damage. Do they just pull out?

You may want to check my last posting about fuel injection.
fuel injection post
The last chapter is talking about the rubber caps and the engine vent hose. The vent hose is a known problem on all the kbikes.
after 20 years the rubber dries and cracks.

When one sprays the selected inflammable potion gas or liquid the idea is to do so with the bike fully warmed up and idling as if it were about to be ridden with no balancing kit attached. In this way one also tests the rubber caps which seal the vacuum nipples that the tester attaches to. What one is looking for is a speed-up in the revs when the flammable material (extra fuel) enters the air-leak, having found it then it is a matter of sealing it. As mentioned above perishing of the rubber caps is a known air leak point on the K-Bikes
Regards,
K-BIKE

I like the suggestion from K-Bike. I think I will try it with the gas spray though. I can grow new eyebrows in the event of a problem, growing a new K100 may take longer!
I take it that the places to check for leaks are the cylinder head / manifold joints, injectors and blanking plugs. Anywhere else?
Different people have suggested that it could be the blanking plugs but as they are not used when using the Carbtune, this shouldn't be causing balancing difficulties?
Bert suggested that when I removed the oil filler plug with the engine running, if there is no difference, I probably have an air leak. Tried it today and it does indeed, run like crap. Sooo... do we still think it may be air leaks or any other thoughts?

'Just for the fun, when your bike is iddling open the plug where you refill the oil in the engine. Your bike will start to run like crap. This has the same effect as the vent hose cracked. If you don't see any difference in the way that the bike is running, yes you have an air leak somewhere in your system.'

Good places to also check are around the sockets the injectors have with the head if they use the same o-ring supplier as Volvo they get hard and brittle and leak badly. with the gas around them you can hear instantly if it speeds up proving you have found at least one spot, keep going until all are found. One result of fixing air leaks can be that when all the the sealing is done the idle needs to be adjusted since the air leak is no longer supplying extra air and it is sometimes necessary to tweak the idle up.
Regards,
K-BIKE

the places that i found that were leaking were the intake stubs the ones that connect the throlle bodies to the head
and the tube that connects to the air box
im sure the injector o rings were not sealing
i replaced them as a matter of course
the came with the new injectors
well worth the investment
after inspection i found the spray patterns were all different
so i bit the bullet
ut if you cant set the cylinder up within the range offered
look elsewhere
if you are confused about he gauge swap cylinders
my throttle linkages were out from damage
also the discs which are the throttle valve
werent concentric in thier bores so had to be loosened and [patiently]each in turnhave to be adjusted so tha at rest
thry {there are four] are all concentric
[any one that wasnt held that throttle open and there was no way i could set it up
but once it was done oow ahh

one could use water to check for vacum leaks
any flamale substance offers the chance of an explosion or fire
a spark plug could be leakig comustion'could be an ignition leak
if you dont know what you are doing
dont

Hi Folks,
Sorry I do not believe water will work for vacuum leak tests as water will not burn hence the engine will not speed up as the water enters the leak spot. Using WD40, Carb Cleaner, butane or propane is a well tried and tested standard method of leak checking. The crucial point is the quantities in use are so small that any fire from an ignition spark will be minor and especially if one is using gas will dissipate almost immediately. I have never had a fire in doing this dozens of times on some really ratty engines.
Regards,
K-BIKE

Decided to stop messing about and removed the injectors the other day. The 'O' rings didn't appear to have any cracks but did seem to be harder than new ones and didn't look like they would be a tight fit in the port. Suppose after 20 years it's not surprising.
Hats off to Motor Works for an excellent parts service. Ordered the 'O' rings online on Tuesday night and they arrived in the post on Thursday morning!
Put the injectors back in this evening and started her up. Even though it has been in a very cold garage and hasn't been started for a fortnight, it started easily. In the past, it can take a few turns of the starter, even in milder weather. Maybe a good omen.
I'm keen to see if the injectors can be synced with the Carbtune any better now. Should get a chance on Saturday to try it.
One tip I found online and did while waiting for the 'O' rings was to clean out the air screw adjusters before setting them up. Do them one at a time, counting the number of turns to fully close, then remove and clean the screw itself. Use a cotton bud to clean the screw seating.
I was amazed at the amount of black gunge in the seating. Can't do any harm to do it before setting up the injectors.
I'll let you know how the syncing goes on Saturday.

Thanks John.

I would be nice if you can detail the syncing with few pictures.
Just a wish to educate people.

Bert

Good idea Bert. I will take plenty of photos. How feasible would a 'How to' section be? Maybe common service things like this or greasing the splines, etc.. The more experienced owners could pass on practical tips not found in the manuals. Just a thought.

Good idea John.
I am creating this section right now.
You will have the privilege to inaugurate this section.