Heat Risers - Clearing Carbon

[KKV270]

Hi Guys..

Glad to be tuckling a new problem...and thanks to HercDriver who pinned this down the very first time I raised my 1st problem with my beetle (sudden power loss).....Yes HercD,,,,you were sure right.

I have a blocked pair of heat risers full of carbon. Was able to drill the bends but no bit long enugh to get the job done pronto. Anybody with suggestions on ways I can get that stuff out fast enough? The hunger wire is pretty slow,,,but seems to be the only thing I can get in there.

Just for the record, I had a lovely experience getting to the manifold. I am enjoying this beetle mechanics thing...okay, suggestions and assistance.!!!!!!! Driving the car is more fun...

[Blue Baron]

I have no sure method for unclogging a plugged heat riser.

We have the advantage of large VW swap meets in Florida. I had to check about half a dozen manifolds before I found one that was clear of carbon.

[KKV270]

Hi.

How fortunate for you Blue Baron...to have available parts around. I was surprised at the response I have gotten from around.... guys here tend to ignore the matter and say it's no biggie... I wonder how they go on>

I've made head way the hard way....twisting metal inside. Seems like I'll be done in a few hours.

Eager to see the significance it will do to the performance.

Cheers.

[h~moto]

I think that many years ago I may have heard someone suggest using oven cleaner to aid in cleaning the riser out. I have never tried it and I don't know if the person had a clue what they were talking about. If you do try it, I would think safety goggles would be a good idea.

[hercdriver]

I haven't done the job myself, but others have used an old cable and a drill. Take an old cable (a clutch cable or other like thickness) and unwind one end. The tip will now be frayed. Take the other end attach it to your drill.

If that fails, others have drilled a hole in the bend to gain access to the middle section and then brazed the hole closed.

[rknowles]

You could try a toilet snake (looks like a hand drill with a flexible metal snake about 3ft long on the end of it.) I used one to clear caked myd out of a motorcycle exhaust that had a 90-degree bend in it once.

[glenner]

Maybe it's a little late, but I just found this site last night.
In my John Muir he uses an acetylene torch to heat the carbon and tube and then hits it with straight oxygen to blow out the carbon. It worked like magic when I tried it 40 years ago, probably still does.

[KKV270]

Thanks Glenner.

I chose to use the "hard wire" to clear the carbon off. it sure did take me a while but found it safer as I was careful to heed to the precaution that the blazing oxygen caould do to the aluminium that holds the manifold and heat risers.

Cheers.