Blowing smoke

[61 panman]

Hello,
When starting my 61 Fl about 30 seconds after starting and for 1 to 2 minutes after that my bike blows a good amount of white to blue smoke out of the rear cyllinder. I thought it was gas leaking into the intake manifold and heading for the rear cylinder but I fixed the float valve and do not think this is now the problem. The bike runs great other than this. The heads were rebuilt about 5000 miles ago. and it only happens from the rear cyllinder. After the 30 seconds I can just barely hear a change in note from the rear left side pipe and the smoking begins
Any thoughts.
Thanks,
Doug

[AdminGuy]

At the end there. and the smoking begins or ends??? was that a typo?

I am NOT a smart guy. My guess. Exhaust valve guide. Do exh v guides both cyl. Buy good quality guides. gas gets burnt up then it draws/suuccks oil.

M.Olson? What do you think? And your Dad is "DA MAN". Tell him that.

[61 panman]

Thanks for the reply, I guess I was not too clear on my description of the symptoms.
I start the bike, two primers and always starts on the first kick. The bike runs for 30 seconds and then smoke begins to pour from the rear cyl exhaust pipe. I have seperate dual exhausts. The bike smokes big time from the left rear pipe for about 2 minutes then it clears up. I have bronze ampco 45 guides in there, no valve seals, I put the heads together after having new hardened seats put in and all parts were checked for clearance.
The only thing I did not do was carefully check the fit from the rockers to the rocker blocks. I eyeballed the clearance and gave it the old wiggle and shake test. It seemed fine.
I normally would just pull the head but it is a nightmare to get the rear exhaust pipe back on so I am checking if anyone recognizes these symptoms.
Thanks,
Doug

[Carl N. Olsen]

smoking panhead

You should use Rowe cast iron guides cut down for valve seals. Along with Rowe nitride coated valves. With this combination you can set up the valve to guide clearance tighter which will give longer life to your parts. Clearance on the intake valves is .001 to .002, and on the exhaust .002 to .003. Depending on your style of riding and climate. You should ream and hone your valve guides and check fit with plug guages in .0005 incriments. Also you should have a stem protrusion of 1.5 to 1.55 for proper rocker arm geometry. It is not neccesary to run intake valve oilers with this combination of modern day metals, but if you do make sure and put in new ones. You should also re-surface your rocker arms to remove any wear patterns. Pull the pins from your rocker blocks, resurface the brass tops with emery paper on a surface plate. Surface grind the cast iron bottom approxiamatly .005. Deburr and clean the freshly resurfaced parts and bolt them together after replacing the pins. Line hone the hole for the rocker arm to a clearance of .003. If your rocker arms bearing surface has grooves or scores, replace them with new ones. Make sure when your bolting your rocker arms to the heads, that all oil passages are free and clear. If you follow these instructions your heads will last another fifty years.

[61 panman]

Carl,
Thank You for the reply.This sounds like a job for an expert. I agree with you on all this. Except maybe cutting down the guides for seals as I have heard valve seals are mainly for pollution control and these old engines can run just fine without them and benefit by a little extra lubrication. I reused the old oilers as they are stamped sheet metal and I cannot imagine how they could wear out.
I am not inclined to take the heads off just yet as the bike runs great except for this blowing smoke upon start up. But when I do it looks like I will be shipping them out to you.
Thanks again,
Doug

[61 panman]

Carl,
One thing I forgot was there is an odd concidence here. The guy who rebuilt my heads and no leaded them about 5 years ago ran a shop called "Olsen Engine". He is in NY so there is probably no relation. It is a clean well equipped machine/speed shop that does all the machine work for the local HD dealer.
Do many people ship engine work to you?
Doug

[Carl N. Olsen]

Smoking Panheads

61 Panman,
The Olsen Engines are no relative, but with a name like that they sound very competent. The oilers can and will get carboned up and thus malfunction, that is why replacement is recommended. I do alot of work all over the country as people send me motors and bikes to restore. Not alot of shops today do not have the tools and/or knowledge for our old iron. I am in the middle of 8 motors right now, 40 UL from Arkansas, 38 EL from Indiana, 38 EL from Iowa, 39EL from North Dakota, 49 FL from North Dakota, 46 EL from Las Vegas, 51 FL from Colorado, and my son's 45 FL. I just finished restoring 4 47 Knuckles, 2 EL's, local and Wyoming, 2 FL's, California, and New Jersey. I am almost finished with 2 39 ELs, one for me and another for a collector in North Dakota. There is always something going on at Carl's Cycle Supply. I am teaching my son Matt how to build Motors now in order to lighten some of the load, he is 17 years old and like a sponge, I can not give him enough. We make a good team as many in the club well know. Check out the latest club magazine for an article on Matt in the FYI section. If you have any questions you can give me a call at 605-225-5702, I will be glad to help you out, as I have done to so many others in the past. After all that is what it is all about, our love and passion for old motorcycles and the joys of riding them.
Carl N. Olsen

[61 panman]

Carl,
You are a truly blessed to have such an interesting business and a son who is involved in it. I was looking at Matts bike last night on the computer wondering how an 18 year old could accomplish such a beautiful build. Never realizing he was your son. Today I put two and two together. I read his posts and can see he is a well spoken young feller also.
Thanks for the posts,
Doug