Topic: Wha have I done!!!

[JohnCurW]

So I decided to run some carburator cleaner (seafoam) through my 78 CB750A to fix it's erratic idleing.  I dumped about half the can into the gas tank as suggested by someone here and, on suggestion of my father (who knows a good bit about motorcycle repair/maintenence) took off the air intake and trickled a very small amount directly into the the carbs while running the engine.  After doing this with two carbs I noticed that my exhaust pipes were glowing red, bright red.  So I shut the engine down and watched the glowing slowly fade and prayed (for the first time in years) that I didn't just majorly damage my engine.

Any Ideas what I did wrong?  The label on the can suggested this type of use also.
-Motorcycle was in nueteral, warm and idleing fairly high when I began, introduction of the carb cleaner raised the rpm a little, but not enough to scare me.

Any ideas on what I should check for damage?

Anyways, I think my do it yourself kick is over for a little while, at least unsupervised.  I don't have much experience working on motorcycles but I'm a mechanical engineer, You'de think I could figure this stuff out...

[BVCB650]

First of all, you only put in 1 ounce of foam per gallon of fuel in the tank. I don't know who told you half a can but they were not right. How does it idle now? I suspect you may have some valve damage, but if it runs fine now with no new smoke, you may not have melted a piston. Best to read instructions on the can.

[steam-powered man]

don't kick yourself too hard, these engines are friggin' stout.  

suppose you could check the plugs for heat damage, then change the oil 'cause of possible viscosity loss.  refill w/the good stuff, then have a cold one.  

not meaning to make this sound trivial, but these engines are well-built, well engineered, and can take a few on the chin.  
bobp

[BVCB650]

LOL. Cherry red exhaust pipes is a knock out. TKO

[manjisann]

If you took the air intake off the carbs you may have had an overly lean mix which would cause the engine to overheat. That may have been why your pipes were cherry red.

Don't give up on your DIY, just read instructions from now on

Brandon

[BVCB650]

If you took the air intake off the carbs you may have had an overly lean mix which would cause the engine to overheat. That may have been why your pipes were cherry red.

Don't give up on your DIY, just read instructions from now on

Brandon

I thought of that, but he may have had some belching from the carbs if overly lean. We need to know how long he idled it. Also, how much raw sea foam was "trickled" into the carbs directly. That probably didn't do anything for cleaning the carbs, but nuked the combustion chamber bigtime.

[JohnCurW]

It was getting pretty late last night when things went wrong, so I haven't run it again since then, soon as I get off work I'll be checking though.  I followed the can's instructions on the amount to put in the gas tank (it gave a range and I went towards the stouter end of that range, and everything ran fine with the carb cleaner in the tank.  It wasn't until I trickled some carb cleaner in through the intake that everything got so hot.  Anyways, thanks for the replies, I feel a little better about it all, I'll change the oil this evening.  Any ideas what else could be causing my engine to start out ideling low and very quickly go to a high idle?

[JohnCurW]

It wasn't Idleing for more than a minute or two after adding the seafoam, and I trickled maybe 1/16th-1/8th of an oz into each carb, the can says you can do this, but doesn't give an amount to use or a rate or anything.

[BVCB650]

Since the nuking was localized, I feel the oil is probably OK. I doubt your whole engine overheated. Just the combustion chamber which as you know, went badly very quickly. Kind of like injecting propane into a diesel pull tractor. I've seen those manifolds glow for 5 minutes afterwords. You may have an intake air leak that might cause the irratic idle rpms. On my can, it says 1 oz per gallon in the fuel.

[Hinz]

it's 1/2 a can for a CAR gas tank.

[JohnCurW]

1 oz/gallon X 5 gallon tank = 5 oz. I actually used a little less than half the can so call it 7 oz.

Maybe I added a little too much, but again the bike rode fine that way.

[BVCB650]

Well, in a full tank, that dilution ratio may have not done anything, but the combination of maybe too long idling, rich mix in the tank and raw foam in the carbs may have done it. 3 strikes and you are out. I hope not. Just have to fire it up and keep your fingers crossed.

[GammaFlat]

Whenever you're in your garage and you know you'll be idle your bike for a while - especially for extended periods or at higher idles, I think it's a good idea to point a box fan at the front of your bike.  

[Steve F]

When mixing stuff with the gas, you should pour the stuff in, and then fill the tank to mix things up a bit before it has a chance to get into the carbs undiluted.  What I'm saying, is that you could have poured the stuff directly over the petcock, and if the stuff is heavier than the gas, it would go in full (or near full) strength, kinda like drain cleaner.

[BVCB650]

I don't usually haul the stuff with me to the ags station. I just add it when I get back home and slosh the heck out of my tank with a side to side motion. But your method is foolproof.

[Steve F]

Well, have you tried to start the beast after all of this?  Curious to find how things went.

[BVCB650]

I'm curious too. I didn't see a mushroom cloud or anything.

[Ogri]

You ran it super-lean IMHO. The engine sucks in approx 1 part gasoline to 14 parts of air. At this ratio your bike will run not too lean and not too rich.
By adding the Seafoam to the petrol and then directly into the carbs, you changed the ratio. That 1 part gasoline was reduced so the ratio became the equivalent of 1 part gasoline to 20-30 parts air. Then you took off the air intake so there was even more air available. Ever seen a blacksmith's fire when he pumps the bellows? Same deal.

[JohnCurW]

Didn't get a chance to ride yesterday, but I started it up and everything seems fine at idle, weather is looking find today so I'll find out for sure once I get off work.

Still feeling like an idiot but I still don't understand what went wrong; The seafoam is just isopropyl alcohol with a little naptha added if I'm not mistaken and I definitly understand that taking the air filter off would cause the bike to go a little more lean, but this isn't some obscure process that has never been done before, so why has no one else overheated their engines?

And as far as sitting Idle, I started it up ran it around the block a few times to warm it, then it took me about five min. to get the air intake off and another two to induce the seafoam into just two of the carbs, it really wasn't ide for that long.  I was also under the impression that if I induced too much seafoam into the intake the engine would just die.

My head hurts, but I'm happy that everything seems ok.

Going to ride it around some this evening and then check for air leaks as BVCB suggested.

[Cvillechopper]

Could be that you were not actually burning all of the additive in the chamber and it was igniting in the exhaust, causing the glowing red pipes so quickly.  Might not even have overheated the engine.  At least that's the "here's a little hope for you" possibility.

[razor02097]

I have done the seafoam "treatment" to my jeep.  Will not do it again.  Involves putting it directly in the intake and shutting the engine down then start again.  The Jeep smoked so freekin bad for a long time it was some nasty sh@t coming out of there...  Ended up ruining both O2 sensors and blowing the Cat honeycomb out the back of the tailpipe.  Expensive fix but all is well now.  Putting that money toward tuition in the school of life lessons.

[MacM2010]

Don't feel too bad - at least it wasn't an energy drink.

http://forums.sohc4.net/index.php?topic=51867.0

[JohnCurW]

Thank you, I feel alot better after reading that...

[BVCB650]

I have done the seafoam "treatment" to my jeep.  Will not do it again.  Involves putting it directly in the intake and shutting the engine down then start again.  The Jeep smoked so freekin bad for a long time it was some nasty sh@t coming out of there...  Ended up ruining both O2 sensors and blowing the Cat honeycomb out the back of the tailpipe.  Expensive fix but all is well now.  Putting that money toward tuition in the school of life lessons.

When I used it on an old outboard motor, it sent out a smoke screen that would have made the boys on D-Day proud. But that is what it is made for. Put it in, then let it sit for a spell, then fog away. Not keep a steady flow going in while continuous running.

[Don R]

I have used it with success. Your exhaust smells like you are burning coal for a while because of all of the carbon coming off the pistons and valves.