Rx-1 Blown Engine

[King9144]

This is a long and painful story but here goes...
I bought a 2003 RX-1 from a salvage yard in 4/2004 for $2650.00. The right bulkhead was ripped off. Apon starting the engine it puked oil out of the ripped open oil tank but appeared to run fine otherwise. I repaired the front end and waited for winter. Winter came and I rode the sled 1/2 mile and while idleing it started knocking. Checked oil and water and were both warm showing circulation. Started engine again revved to 2,ooo rpm and threw arod thru the block. 12/05 welded block bought new crank and rod. Replaced exhaust valves in # 1 cyl due to hitting the piston and checked intake valves by lapping. Yesterday rode sled for 5 miles, initially started and ran fine and then began skipping and spitting gas from 2 & 3 cylinders. Was running sluggish. Shut off and wouldn't turn over. Today removed head to find broked intake valves, smashed spark plug, and a hole in the piston. There was no rapping noise at all. Also this was not the cylinder that I repaired. I'm ready to burn this sled!! All rod and main bearings were plasticgaged at .001 or less. Rod bolts and nut replaced too. The engine was full of coolant when a bought from salvage so overheating is not likely. This is my first motorcycle type engine work.
I remove the bottom in a few days to see if there was any lower end failure. What am I missing.............

 

[Honk]

well brand new that sled was 9 grand, so ya got a long way to go! you are still way ahead! Honk

 

[Sled Dog]

At this point I would either buy a new sled and part that one out or do a complete engine rebuild at a Yamaha dealer. Sounds like some things were not looked over properly on your first build.

 

[King9144]

After removing the cyl head I was surprised to find the middle intake valve keepers or locks missing from their seats. This explains middle two cylinders were spitting gas when running. I never looked at those cylinders because there was no apperent damage. I've never heard of these keepers falling out. The keepers fell out of both middle valves on # 2 & 3 cyl.

 

[yamahajunkie]

"I bought a 2003 RX-1 from a salvage yard"

clean one owner eh! sorry, but you should of shopped around.

 

[Skydog]

Yea dump that thing buddy!!

 

[novarossi]

Bummer man. Do those things have titanium valves?

 

[rxrider]

When you had the head off there is a chance some of the valve shims went out of place, if so engine failure will happen very soon.

 

[Mongo 1]

Improper cam timing.

 

[RX1Jim]

King,

I feel your pain. I had the same thing happen to me on a 600 cc Honda engine I rebuilt for a freind last winter. After very carefully rebuilding the top end of the engine, I started it and it ran fine. I started hearing a ticking noise that was louder then the usually noise due to the valve clearance. I shut the engine off and when I went to restart it it would not even turn over, felt like it was seized. What happened was the keepers poped out of place on one exhaust valve. the valve dropped, broke in half, cracked the valve guide and put some minor marks in the top of the piston. The reason for this failure was I did not "seat" the valve keepers by taking a brass punch and hammer and sharply tapping the top of the valve stem. I repaired all of the damage, assembled the engine and it has been running great. Had there been more damage to the top of the piston, larger dents, i would have replaced the piston and the bearings on the rod. I suggest you take a look at the rod bearings for any cylinders which dropped the valves. Don't give up, you'll et it running right.

 

[King9144]

Just reassembed the engine and it runs fine. Replaced piston, all valves, valve locks, and valve seals. 8 of the 12 intake valves started to shear the area were the valve locks (keepers) go causing the valve to come loose and stick open and get hit by the piston. I feel due to the lack of oil the valve train was overheated and the top of the stem lost its temper and became soft. The keepers remained harder due to disapating heat to the spring cap. The harder locks sheared the valve stems within 5 miles of riding. Appearenty the exhaust valves could handle the extra heat as they showed no signs of this problem. It's now for sale.

 

[yamahajunkie]

please tell the person that buys this, the history you have on it. it would be a shame if on their first ride it blew up. wouldnt look good for you or yamaha.