Carbon buildup

[frossa]

What can be done to prevent carbon buildup on pistons and heads? THe reason I ask is because recently I took my bike out(1999 R1100RT, 69,900 miles) and got about half a mile from home when the engine started "rapping, clacking". Limped home and transported to dealer. Tech says sounds like botton end noise. They were able to start it, idle smooth but noisey. Remove jugs, inspect connecting rods, bearing, crankshaft. Nothing out of spec but large carbon buildup on piston head and valve head. I use high test, but I do not ride aggressively, except for getting onto highway(6000-6500rpm). Can something be added to fuel periodicly to prevent this. Repair will be around $1400. Thanx

[4wheeldog]

Riding at WOT (Wide open throttle) regardless of speed attained, will help more than anything else.

That said, their are several additives that folks have found helpful. My favorite is Techron (By Chevron, available at Wallyworld). The concentrated stuff, not the Progard. Using 6 oz in a tankful, maybe that dosage in 2 tanks in a row, just before an oil change, is a healthy habit. Others like Seafoam, others use a Yamaha product, meant originally for marine motors.

Good Luck!

 

[SAAB93driver]

Do you still burn a fair amount of oil or not. Could be carbon left over from long break-in period these engines are known for.

 

You'll get a lot of answers on preventing it. Seafoam, BG 44, Techron, top tier gasoline, rev it higher.

[Mark K]

As said -- keeping the revs up helps a lot. Just when you think you're thrashing it.......that's just about right for these motors.

[Skywagon]

This will sound like an oxymoron, but heat. If your engine is too rich, keeping it too cool, carbon will build. I concur on Techron. I buy Chevron Premium as a normal course. An old trick from the 60's and 70's used to break up carbon on pistons....and before I say it let me say NOT RECOMMENDED - BUYER BEWARE, was to put a little mmo or atf in the plug hole. let it sit a few minutes then run it hard. It will burn it off. It happens in airplane engines all the time with lead build up. We lean them very agressively when in flight and burn it off. AGAIN I WOULD NOT DO THAT IN MY MOTORCYCLE.

 

I would check the mixture and start running it a bit harder. No lugging.

[4wheeldog]

http://www.seafoamsales.com/how-to-use-sea-foam-motor-treatment.html

 

Go down to "Cleaning Varnish and Carbon Deposits - Fuel Injected Engines"

 

(Standard disclaimer) I have never actually performed this process (Nor needed to....) but I would try it before I disassembled an engine to de-carbonize. Perform at your own risk.

 

[frossa]

Thanx all.

[notacop]

One can spray water in the intake if you pull the tubes off. The expanding steam will blow the build up away. You need to maintain a higher rev when injecting the water.

Or like others have suggested ride it as it was designed to be. Don't lug it so much. 6th gear at 30 mph is just wrong.

[SinNH]

At about 3000 r's, for years, I have squirted MMO in the carbs on all my type 247's and I do it a couple times a season with my R1100-- and-- as already stated Tectron before oil changes, I use a half a bottle/full tank.

My boxers never see below 3500, unless crawling through traffic.

[ProductUser]

Try bgk44 fuel injector cleaner if needed. It's on the pricey side, but it's really good. NAPA may carry it in your area.

 

As stated, run the boxer at high RPM's.

 

Tony

[Joe Frickin' Friday]

Try bgk44 fuel injector cleaner if needed. It's on the pricey side, but it's really good. NAPA may carry it in your area.

 

This worked on my '99 1100RT when I had knock problems in the third and fourth seasons of ownership, but the results were only temporary.

 

As stated, run the boxer at high RPM's.

 

I'm not clear on why high RPM's alone would help carbon buildup. As others are suggesting, heat seems to be the cure, which means high power output. WOT acceleration whenever (safely) possible, AND let the revs get up there. Find some twisty roads, and beat the hell out of the motor.

 

Two more tips:

 

1. earplugs

2. willful ignorance

 

If it's been established that the knocking isn't severe/prolonged enough to cause damage, then start wearing earplugs (if you don't already do so), and when you hear that pinging/knocking, just ignore it, and know that the engine is fine. In '02 I had my engine apart twice; when I confirmed that all the parts were in spec, and there was no visible damage from knock/detonation, I decided to ignore the sounds and just ride hard. Eventually the carbon burned off, and the engine was fine. I sold the bike a couple of years ago with 135,000 miles on it, the engine as healthy as it ever was.

[blackyam]

Hi. A few of y'all mentioned putting in half-a-bottle of Techron in a tankful of gas. I recently put in a whole bottle of Techron in one tankful. Was I an idiot (again)? Did I do something really bad? TIA.

 

---John.

[4wheeldog]

Hi. A few of y'all mentioned putting in half-a-bottle of Techron in a tankful of gas. I recently put in a whole bottle of Techron in one tankful. Was I an idiot (again)? Did I do something really bad? TIA.

 

---John.

 

No harm done......Just perhaps a bit of a waste of money. It might actually do some good, if the problem is carbon buildup in the cylinders. But for the fuel system and standard PM, it is just over kill.

[blackyam]

Thanks, 4wheeldog. Thank goodness. I can be such a dope.

 

I thought that I'd use Techron in a tankful just before every 6k mi service (that was my first one) because I generally fill up with Sam's Club gas. I'll measure out half-a-bottle next time. Thanks again.

 

---John.