The Hodaka Club Forum

The Gang has been guiding me for the cooking of the Wombat exhaust pipe to remove carbon products from within. I am reporting the operation to be successful. I did add a little science (my wife calls me Dr. Science) to the project by weighing the pipe before and after the inferno treatment. The test revealed that slightly over 1/4 pound of solids were removed during the process. Here's a few pictures showing all the fun. I'll add this to my list of Hodaka experiences! Now on to building a new lengthened header pipe.

Max

Greetings Max

Nice fire!

If my memory is correct, in the original "On Any Sunday", a desert racer burned out his Husky's exhaust in the middle of nowhere. Unfortunately, it was still attached to his motorcycle. This way is much better.

When you start your bike with this pipe the first time, my suggestion is that you leave the spark arrestor out to see if any amount of debris gets blown out. I did this with my 250SL, and a bunch of half burned insulation material was ejected which would have plugged the arrestor.

Tom

Thanks Tom, sounds like a good idea. I also tapped around on it after the fire with a small hammer and several black flakes fell out. I think I'll follow your advice.

Max

Cook outs are always fun aren't they?

Dale, that WAS fun. I did giggle when the flames erupted from the ends, just as you said would happen.

Max

PS--My wife said I was easily entertained which is probably true.

Thank you for recording the weight data Dr. Science! And here is the equivalent of your quarter pound(+) of nasty carbon build up.

Ed

Yep, cookouts are mighty fun. Friends with forges are the best kind.
Laurie

Bullfrog wrote:Thank you for recording the weight data Dr. Science! And here is the equivalent of your quarter pound(+) of nasty carbon build up.

Ed

Ed, that's a good illustration of what could be lurking in our pipes. I was somewhat amazed at the final weigh-in. I expected only an ounce or two and your visual clearly shows this to be a needed maintenance item.

Max

PS--and Laurie, again, there's more than one way to skin a cat!

Hey Ben, how about a BBQ?

RichardMott wrote:Hey Ben, how about a BBQ?

Timely Rick, Just finished reading your article in the soon to be out Resonator. Ben will know all the tricks of the trade including pipe BBQs thanks to you. Great project!

Maxie

OK, a little more geeky Dr. Science stuff. Ed's scales are probably way more accurate than mine so comparing apples to apples I put the pipe back on the scales and added charcoal lumps until I got the combination to weigh an even six pounds as it weighed before burn-out. I ended up with six lumps to Ed's five which means it's even worse than I thought. A little more scientific study would probably reveal that Ed has wet charcoal.

Dr. Science

Aw, what's a 1 lump difference between fellow scientists? (It's still quite a lot of nasty carbon build up!)

Ed
PS: Kingsford brand charcoal is the standard of choice for this type of scientific research. Didja know that?

Kingsford it was, you might of had a denser batch but mentioning that you had wet charcoal sounded funnier.

Maxie

PS-- the speedometer read 4,689 miles which we could add to the database. Preliminary calculations reveal that carbon could accumulate at the rate of 1 lump every 780 miles or about 1.3 lumps per 1000 miles. Dr Science is on a roll.

Now I want to see you figure out how much carbon is generated per ounce of premix oil. Or... Maybe you can prove that Hodakas are environmentally friendly because all the emissions end up being stored in the pipe.

Brian

Funny Brian, I'm still giggling about the emissions being stored in the pipe. I never considered that and that would be partly true if we didn't set fire to it occasionally. Anyway, being serious (which is hard for me to do), maintenance schedules could be figured out by weighing the exhaust pipe occasionally and removing the carbon as deemed necessary rather than all of these funny calculations.(But what fun is that?) All in the name of science!

Max

To be scientific, wouldn't you need to factor in the brand of oil and the ratio being used?

Dale, It does get the brain to think about all the processes that cause carbon based crud to form in two-stroke exhaust systems. I remember the frequent closing of the exhaust port when using castor oil in the early days. I would think jetting would also be a big factor with not only running more oil and fuel through but rich mixtures causing incomplete combustion. I suppose that reflection points in pipe design could also deposit pollutants in certain areas and on and on. All fun to think about.

Question; what do you chrome pipe guys do to deal with the problem? (Plumbers drain snakes come to mind.)

Max

Science--Love it.

Actually a sticker on my tool box. Dr.Science was a character on Public Radio that answered questions like: Why are there two prongs on electrical cords? Answer: That way the power can come in on one prong , be used and be sent back to the power plant on the other prong, where they send it back to you again if you're stupid enough to buy it.

A little slow in the shop today.

Maxie