Carburetor Cleaning/Soaking

[George]

Piston comes up the same amount regardless of the timing belt teeth. Hitting a spark plug is hard to do if it's the right plug. Hmmmmmmmmmmmmmmmmmmm.

We never screwed with the timing belt. The bike is virtually new.

David?????

 

[Splash]

All,

Thanks for your thoughts or suggestions.

After a visit to the dealer today, a mechanic pointed out that the plug was not hit by the piston. Instead, it appears the NEW spark plug (NGK Ridium CR8EHIX-9) lost 3/4 of it's ceramic insulation. Most likely, it is the piece of ceramic that caused the damage to the plug and potentially the valves. The plug looks very bad but is still intact. The ground electrode is contacting the center electrode.

Tomorrow morning I am going to inquire with NGK about their claims process and what is needed to have them cover the cost of repairing any damage. Since the engine is so noisy, the mechanic expects valve damage.

The noted motor hesitation I mentioned in an earlier post may have been related to the exhaust valve pulling out the broken pieces of ceramic. The piston appears okay, just a bit black.

Tonight, I am going to inspect the valves and try to turn the motor over by hand.

Question: Does anyone have any suggestions of approaching NGK about a very rare failure? The plugs were brand new, purchased from a Honda dealer last week. I'll post a couple photographs as soon as possible.

 

[BigTom]

When I worked on a race car (dragster), we used NGK exclusively. With .70 cold valve/piston clearance. We changed the plugs every pass and had 0 failures in 3 years, maybe 800 (x8) chances.

I have used NGK without question for 40 plus years. I am dumbfounded at a failure.

I'd hope that your luck changes sometime soon.

 

[Splash]

NGK plug failure photo #1

 

[Splash]

Plug with 3 miles missing the ceramic insulator!

 

[jaysponger]

oh crap! I use iridiums on my cars, and about to use it on the ST. Hit me up if you need help taking stuff apart/putting it together. You still got my number right?

 

[Splash]

Perhaps a better image... after enlarging the photo.

 

[George]

Sure you didn't drop that plug on the way to the bike, David? (Ok, prolly not, just devil's advocate.)

Anyhoo, that is really tuff luck. I've used the Iridiums in three bikes with no problems for prolly 250,000 miles. The only diff between these and other NGK plugs is the electrode wire.

I'm afraid the only thing you might get out of NGK is a refund on the price.

Find a <edit>tube that'll fit into the plug hole and vacuum <edit>the bits of ceramic out. Put a rag over the back end of the tube where it goes into the vacuum hose to capture those bits. Might be some evidence.

The ceramic is extremely hard, could cause a bent valve if stuck between the valve and it's seat as the piston comes up. Also could easily score the cylinder wall, jam between the piston and cylinder wall, break a ring. A very UGH moment for you. Maybe this beauty of a low mileage 96 ain't so cheap after all.

Keep us poSTed on (any?) progress. Really sorry to hear about this.

 

[saaz]

That is bad luck. I have used NGKs for 30+ years in bikes with no issues at all. Iridiums in the ST11 for the last 50,000kms (same set). I suppose no mechanical device is 100% failsafe, just sorry you have had a problem.

 

[Splash]

Jay/George/Saaz/All,

Hello. It's certainly is a quite disappointing experience...especially if this happens while trying to do 'something good' for the near-new motorcycle. The plug was not dropped and I simply can't explain or guess of the root cause. After searching the Net for damaged plugs, I learned of others with similar experiences, however it is very rare.

I haven't had time to check the valves or to learn of any other damage. I'll probably take it to a dealer on Saturday. Minimal estimates are in the $500 range for valve work. I'll contact NGK once the engine damage is determined. I am sure it would be difficult to be in their business as well, if you were to "put yourself in their shoes."

Saaz, you nailed this one from the beginning. I am a bit relieved it was not the piston doing the damage since that would mean more $$$ for repair.

Sometimes you win...sometimes you lose.

 

[Splash]

This evening, I attempted to turn over the motorcycle engine by hand. Fortunately, the #1 piston was at the bottom of the stroke. While attempting to bring it to the top, the engine initially turned normally then I felt resistance near the top of the stroke. I didn't want to force anything so I left it as that. The valves may definitely be bent or damaged. It's puzzling to me how much abuse an engine may be able to tolerate if one cylinder has bent valves. I suppose it can put stress on everything.

While the engine is being repaired, would anyone suggest replacing the 13 year old timing belt? What other engine components may have been compromised due to the bent valves...belt, plug, seals, bearings? What should a good engine builder be looking for in this kind of situation?

Any feedback would be appreciated.

Thank you!

 

[Splash]

For those of you who have supported me during this troubleshooting journey, I thought you may enjoy seeing the ST1100 I am trying to get back on the road. She's actually a surprise gift for my brother... once she is 100%. '96 ST1100 ABS...now at 3,700 miles.

 

[George]

I wouldn't worry about the timing belt, David, unless the shock of the sudden problem may have caused damage. Other items of interest under that cover are the idler pulley and water pump. Sudden shock can shorten the life of components like that (just like in a wreck.)

Anyhoo, leave it to the mechanic to check appropriate items. Once the head is off, any damage there will show up quickly.

We've had two incidence I know of where an engine would not turn over by hand. Current concensus is the problems were caused by carbon build up. One of the incidents was mine. After hearing about Alan's drawn out attempt to find the cause without success, I put STick back together and started'er up. No problem. That was many thousands of miles ago. So, maybe not as critical as first indication might make you suspect.

Good luck and keep us poSTed. See you at CreSTOC??

Oh, and <duh!> have you done a compression test? That's the quick easy way to diagnose the bent valve theory. If she holds compression on all 4 cylinders, valves are prolly okay. Gotta be able to turn it over, tho, to do that.

 

[Splash]

George,

Hello and thank you for writing. I will make note of the components prone to failure. Since the engine heads will have to be inspected eventually, a compression test was not performed. I am fairly confident there's some damage in the head/valves due to the noise I heard.
In regards to CreSTOC, I would love to join you, but I'll be vacationing in China.

Thanks again & take care!