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1999 R1100RT runs bad, need advice.

Canister vent lines?

First of all I bought an R1100R only 1000 miles ago. I posted here with ride-ability somewhat like these two. Several things were wrong with my bike but one has risen to the top in my mind. The vent lines were reversed prior to my ownership. When the solenoid opened the canister to throttle bodies vent line, overly rich gas/air entered the TB's and the bike ran like cr@p. After a few cycles of this the catalyst was fouled, the bike would not run well even when the solenoid was closed (is the fuel tank overfill vent open to air so the mixture was leaned when the solenoid is closed?). Reversing the lines (the ex MaxBMW tech new enough to check this and several posters here suggested unplugging the wires to the solenoid to prevent it opening) fixed part of the problem. I deleted the canister, routed the vent lines to air and plugged the vent inlets in the TB's This reversing is so easy to check it should be a part of any run-ability suggestion. I don't advocate the canister-ectomy but mine was fouled. Others have told me theirs fell off! Be kind I'm new.
 
Thanks for the response Anton, you hit it right on the head, burned valve with a half by quarter inch piece missing along the edge. I lucked out as there is no damage to the piston and the valve seat is clean and the other exhaust and the intake valves look good. Looks like it got sucked out clean if it did come apart in one piece. When a valve ?burns? does it cause a piece to break off or does it slowly eat away at the same point making it bigger as it goes? I know on some old car motors I?ve seen with bad valves the valve is chewed all around the edge. This was just one section like someone bit it off. Waiting on a valve and I hope to get it together soon.

For those playing along at home I wanted to do a leak down test but I had no easy availability of a true leak down tester. I knew the head had to come off but I wanted to try to better determine what was up before I dug into it. I fashioned some fittings onto the hose off my compression tester and fed compressed air into the cylinder and at TDC I could feel air coming out the muffler, that was pretty conclusive and I took it apart.

Now, why? I?m open to anyone?s theory. I was still bothered by the clearly weak spark to the same cylinder. While the motor was still together I did replace the coil with a known good one and remember the old coil did test good on a stress test they did at a local bike shop. I now have a good clean snappy spark on both sides of the coil tested through the plugs with the gap tester I picked up. Obviously something is different between the stress test and how it performed in my bike. I was thinking (hoping) maybe the valves were somehow held open a bit with some carbon build up and I did try the sea foam fed through the throttle body trick with no improvement in compression. So, could the bad spark be related to the burned valve? Other than the HES sensor being replaced a few years ago, the bike is well maintained and never any other problems in the 62k miles on it. I do not wail on it (maybe I should). Its ridden often and it rarely get started unless I put down 100 miles or more. Opinions?
 
When a valve ?burns? does it cause a piece to break off or does it slowly eat away at the same point making it bigger as it goes?

A channel opens up between the valve and the seat (could be debris, but the root cause is usually a poorly ground seat with insufficient contact) and the hot exhaust gases erode the metal. The seat can usually be saved; you just have to recut it properly (and do the others at the same time).
 
A channel opens up between the valve and the seat (could be debris, but the root cause is usually a poorly ground seat with insufficient contact) and the hot exhaust gases erode the metal. The seat can usually be saved; you just have to recut it properly (and do the others at the same time).

When you recut the valve seats, do you have to do both heads at the same time to keep them balanced?
 
R1100RT Runs bad - mine too - similar problem

Stopped at the shop today. They pulled the head on my R1100RT - same symptoms as the OP. No compression on one side; there was a 1/4 inch chip missing from one of the Input valves. I'm glad I did all of the fuel supply maintenance - it was due anyway at 105k miles. And clearly my HES was in poor condition and could have stranded me in wet weather, even though it wasn't the cause of this engine failure.

We'll get together in the next day or so to decide on the scope of the repair work. Might just go for a top end overhaul at this point.
 
My R1100RT came home yesterday! What's been the end of your tale of woe bcusack?

It was a chip missing in one of the exhaust valves, not an intake valve. The shop installed a new exhaust valve along with four new seals and a head gasket. Two of the seats were lapped to make to valve/seat mate complete. The engine is running great; very strong pull and smooth (now). I was a little upset that they did all this head work and didn't do a TB synch when they were done. TBs were way off from my efforts to figure out what was wrong before it was discovered that there was a loss of compression on one side. Took me about 15 minutes with a Harmonizer when I got the bike home to fix the throttle cables and BBSs.
 
Yes, I?ve been up and running for a bit but wanted to wait and see before I closed out the thread.

In the end I took Antons advice pulled the other head as I was in there and I wanted to be sure I had no problem on that side either. I replaced the burned valve and had all valves and seats recut. Put it back together and it ran fine and no issues other than a somewhat lower idle and it seemed to hunt a little between 2-3000 rpm. I did the required re-torque of the heads at the 600 mile mark and then also did a very careful valve adjustment and a TBS and now have 2000 miles on it since I did the work and it is running like new and I now have regained confidence in the bike. She's a keeper!

Thanks to all for the help.
 
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