Clearing clogged up valves - views appreciated

[bikecat]

Hiya,

Mate of mine has a K1200LT with gunky valves. He has been advised by the mech to (in lieu of a complete tear down) attempt a quick fix i.e. to clean the gunk off with an acetone flush through the engine. Bike is a 11-year bike which was not ridden for about 6 months, mileage 42,000 km.

Views on whether this flush will work? My own view is that there is no quick fix to this problem and that the gunk has to be manually removed through disassembly. One concern is the effect that acetone has on seals and gaskets.

I know this is old school etc and a K1200LT is hardly an old school bike, but I really have faith in the views and wisdom of the inmates here, and hence post this here.

Pics of gunky injectors will be up as soon as I have them.

Cheers

[ericrat]

I vote for Seamfoam. The magic cure-all in a bottle!

There are directions on the back of the bottle to administer it into the intake through a vacuum line. This is a "solid fix-up" for carboned up valves in certian years of Land Rover V8s I used to be involved with.

Seafoam is available at many autoparts stores.

Good luck,

Eric

[4ad]

check out bimmerboard.com (car forum) for info on doing it by injecting water into a hot & reving engine....cold water contacts the hot carbon and shrinks it enough to break it loose from the head...keeping the revs up (around 2000 i believe) ensures it gets blown out quickly.

[eric123]

Originally Posted by 4ad

check out bimmerboard.com (car forum) for info on doing it by injecting water into a hot & reving engine....cold water contacts the hot carbon and shrinks it enough to break it loose from the head...keeping the revs up (around 2000 i believe) ensures it gets blown out quickly.

I put the water into a windex bottle and spray the water into the carbs while keeping the revs 2-4K or so.

[Hughlysses]

Seafoam seems to work well. I've also tried an old mechanics trick I read about, similar to the water mentioned above. Take 50/50 water and brake fluid, shake thoroughly. It makes a foamy mixture. Pour or spray into intake with engine running. Shut off engine before all the mixture can burn out and allow to soak for a while, then restart.

[batoutoflahonda]

Ride it.

If it's been sitting a while. Ride it and see if it clears up. Solvents break down the crud (including crud in the filter)and it ends up in the injectors/carbs. Drain the old gas and change the filter, and run it. When you get the filter out, shake it to see if a bunch of black crud comes out. If so, change the fuel lines as some of the new gas formulas break down the fuel lines.

How do you know the valves are gunked up?

[bikecat]

Thanks for the replies. Unfortunately Seafoam is not an option as it is not available where I am, and shipping from the States is a no-go too.

Here are the gunk:





So any idea whether an acetone flush will do anything? There's injectors cleaner in the market e.g. this:

http://www.shop3m.com/60455029987.html

Reckon that will assist or for maintenance only?

[Hughlysses]

Since you've got the parts off, it appears a couple of cans of spray carburetor cleaner would help immensely. Spray, wipe out with a cloth rag, and re-spray as required. If you're worried about the actual injectors being clogged as well, the injector cleaner should help. You may be able to rig something to run straight cleaner through the injectors which will help even more.

Edit- one question remains though, how did so much gunk get into the intake tract? It could be he has major engine wear resulting in massive oil blow-by making its way through the crankcase breather system into the intakes. Cleaning them may be a short-term fix at best.

[batoutoflahonda]

+1

How many miles are on it, 42,000kilometers (26,000 miles)? It really looks more like oil than foul gas. 6 months really isn't that long for it to sit, and get that bad.

[bmwrench]

Oh-you mean throttle valves! I have never seen a set of throttles this dirty, and have never seen a "K" with dirty intake ports and valves. I would vote for the excessive oil consumption theory, but the breather manifold looks very clean. Was someone running a K&N air filter with the wrong oil or far too much of it, or fogging the intake with a strange oil?

See if you can find someone with an Ultra-Sonic parts washer. If the throttle ass'y will fit in the parts washer, it'll (probably) get that stuff off, and you won't have to expose the seals to destructive chemicals.