Bike 04 RK carb. 41000 mi. true duals. trouble #1, I recently had the cam chain tensioners replaced after upon inspection there was noticeable wear on the inner tensioner. Also replaced stock carb with S&S super E. crank case gasses not going to carb being vented to atmosphere have filter on end of vent pipe. Since getting the bike back cant keep oil in it there are no leaks but have noticed the filter on the vent pipe stays saturated with oil. when the wrench went back with the cam plate could he have some how got the oil pump out of whack causing it to not scavenge the oil from the crank case thus causing high crank case gas pressure which would be forced through the crank case breathers carrying oil with the gases.

Trouble #2, Getting black smoke from rear cylinder when i accelerate hard or when i gear down Which to me means unburnt fuel. I have ran compression test cold and hot.
Front psi cold 130, hot 155
Rear psi cold 102, hot 115
wet test with oil in the rear cylinder hot saw 122 psi not much change.
This leads me to believe there is no ring problem but a valve issue. Could the low compression on the rear cylinder prevent complete combustion of fuel resulting in the black smoke. I have noticed no spitting back through the carb. If it is a valve issue which is most likely the culprit intake or exhaust what can i do to verify. Have not worked on bikes much just using what I know about my old chevy 350 after all it's just 1/4 of a V-8. I would appreciate any and all help to resolve my Troubles. Thanks ABJ

 

Run your oil halfway between add and full on the dipstick when HOT. If you fill it up to the "full" mark, the engine is mroe apt to puke the excess out.

Black smoke means it is running rich. Blue smoke means burining oil. What do the plugs look like? Is the rear cylinder firing? Maybe a loose wire powering the coil?

The black smoke is a separate issue fromt he oil consumption. Spitting back through the carb is a LEAN issue, not rich. Rich means black smoke and sluggish acceleration.

In short, do the following:

1. Ensure you are getting spark to the rear cylinder
2. clean the plugs...the rear plug may be fouled
3. lower oil level to middle of bar on dipstick. You are adding too much oil!
4. clean breather vent
5. You have too much carb. Need to get some smaller jets.

get ready for a valve job on back head. you have a bad valve stem seal, bad valve guide, or a cooked/burnt valve. New seals and hand lapped valves would bring the compression right back up. Easy garage fix, if you have some tools.

~Joe

 

I think you are on the right track thinking valves. Good excuse to freshen up the heads and even go for some extra compression (thinner head gaskets or shave the heads a little). Not sure how to verify without pulling the heads and inspecting.

If you have issues with the rings, that would certainly make for some serous blowing out the breathers. The overfill thing mentioned earlier is very possible too. But I sure don't like what you are saying about the rear cylinder ccp.

Oil pump "out of whack" wouldn't effect ccp.

 

the fact you are puking oil means the pump is working! You jsut have too much oil in there! 1/2 up the bar on the stick, bro!

And....you are seriously rich.....either you have no spark on the rear cylinder, or a lack of compression. The more I think about it, the more a suspect a burnt valve.

rear heads gotta come off.

~Joe

 

Hold the phone.
Prior to the cam chest work, all was good?? And now huge difference in cylinder pressure??
I'd check the to insure the cams are timed correctly, as it would display those symptoms.
Scott

 

Holy crap. Good catch!

I have heard of that happening once in the distant past.

 

Oil from breathers:
Pull the cam chest apart
Inspect the oil pump and check crank runout, replace parts as needed including the scavenge o-ring in the case
Compression:
With the pushrods out brake set and in high gear blow air (Amflow rubber tip nozzle) into the low cylinder spark plug hole and listen for the leak, there is your answer where the leak is coming from.
Fix what's broke

 

Thanks for the information, on the oil consumption issue i generaly take the level no more than half way between add and full and the oil is still vanishing Just made a 700 mile round trip to deals gap nc. when I got back home oil just tuching tip of dip stick. Rear plug fouled with white ashey powder front plug ok. I am getting good fire to both plugs checked it when I did the compression check on the cylinders. My main concern at this point is the oil consumption just don,t have a clue! second is the rear cyli8nder low compression. Thanks again for the info can use all the help I can get. ABJ

 

Whatever it is, it is a COMPRESSION issue. Was the problem present BEFORE the work was done? This is important. If it was there BEFORE, then it's in the head....if not, then SOMETHING in the cam chest is wrong.

Th rich issue is becasue you are pumping fuel into a "dead cylinder".

Please respond....I'm curious on all of this.

~Joe

 

Joe, prior to having the work done i was having no oil consumption issue. change oil every 3 grand never had to add oil between changes. As far as the weak rear cylinder not sure bike has been soild never had a reason to check compression. no noticible issue with smoking or fowled plugs before cam chain tensioner replacement. when I open the cam chest what do i look for as a indication that the timing is off. Does it take special tools to pull the cam plate after the tensioners are unloaded, or will my automotive tools work. If I can't handle it I do know a vey reliable wrench should have taken it to him in the first place. again thanks for the info.