1966 175DT "Right-side smoke"

[TPRICE]

Continuing with my inept abilities, needing to hear from the "old school" guys. Got my project 175DT to finally crank, (sitting in storage since 1989) and it doesn't run bad. But is "smoking" and "blowing" oil out right side pipe something fierce! The City may want to hire me for bug spraying! lol.
I am thinking that a ring is stuck on the right side.... will new pistons and rings from Richard take care of this?

thanks!

[srpackrat49]

Well i,m old school... in the old days you would do a leak down test.... Its alittle had to say,,, but any old school guy will know how to do it..... RIGHT... hope ya can find one.... One thing that folks do is,,, decarben there pipes.. AE burn off all the old oil in them,,, maney ways to do that? come on guys help me out   its just a few things i mite try..... But the leakdown is the tell all.....

[TPRICE]

Thanks... can you describe a "leak down' test? Anyone...?

[OldSwartout]

There is a good description of a leak-down test in one of the threads on this site, use  the search function available at the top of the menu bar.  It involves plugging the exhaust and carb openings, and then pressurizing the engine to see how fast the pressure will leak away.

A heavy right side smoking problem is nearly always a leaking seal in the center of the rotary valve cover, letting the engine suck transmission oil into the crankcase on that side.  A stuck ring on a two-stroke doesn't make it smoke heavily as there isn't supposed to be any oil in the crankcase (other than what is mixed with the fuel by the injection pump).  However, if somehow a lot of oil ended up in the crankcase before or during storage, it can take several minutes/miles to clean out.  Don't be concerned until you've put 10-20 miles on it.

The leakdown test will tell if you are likely to have a leaking right side seal. If so, it's a relatively easy fix.

[TPRICE]

Ok, no luck finding anyone to do a ''Leak down" test, smoke is not all the time, but does have oil coming out on right side and will foul that plug, run on one cylinder, then pick up and run on both cylinders. PDF manuals alittle un-clear and hard to read, but I believe it is sucking crank oil in. Took out baffles and have ran @ 20 miles to burn out old residue.
 Confused... which would it be...the 17mm oil ring on crankshaft collar? 23mm oil ring on rotary disc cover? 100 mm oil ring under cover? or 28 mm oil seal? I know I am asking for a lot!
 The good part.... A 58yr old man, got on a 1966 175DT today and headed down the highway @ 70mph, ( all the nerve I had) at least for now....brakes, lights, horn, all work! What a thrill! the feel, the way the tank and seat molded to me as if it was built for ME to ride! I NEVER got to ride one in their day, couldn't afford one, saw em', seen em' but always from a distance.
 Just this one problem that I need to figure out, that and how to post some pics.

[slawsonb]

Congrats on the ride. The rest is cake!
...bert

[OldSwartout]

 Confused... which would it be...the 17mm oil ring on crankshaft collar? 23mm oil ring on rotary disc cover? 100 mm oil ring under cover? or 28 mm oil seal? I know I am asking for a lot!
 

The problem is highly likely to be the 28 mm oil seal. Not too difficult to change, but you may need a new clutch cover gasket, 23 mm o-ring and it's probably worth replacing the 100mm o-ring, too.

[TPRICE]

Thanks dcr and OldSwartout...the info. was great, now to pull off changing the seals. I have 66' DT175 ser. 16B which is early, still has oil tank under fuel tank. Original owner bike, in dry storage since 79'. Thought if I could get it running then it might be worth spending a $$ or two on.
I cleaned the carbs, lines, new fluids, etc. put a battery on it and got it running! I know everyone is used to this but I am amazed! The bike rides extremely well, a fine machine and everything works! Lights, horn, brakes (after adjusting) and I rode it down the highway @ 20-25 miles. I pushed 70mph for distance, then thought....old tires, an old man, 70mph = "Have you lost your mind!".

Anybody can ride a new bike, they sell em' everyday... I am excited to spruce it up!

[slawsonb]

Good news, you have not lost your mind! You have contracted Bridgestoneitis. Not fatal, but very consuming.
...bert

[TPRICE]

Txs OldSwartout.... I don't see a "clutch cover gasket" , are we talking about the right crank case gasket??

[OldSwartout]

Yes. P/N 2163-8000. I've always called it a clutch cover gasket, never sunk in that it was called something else in the parts book.