Help with bogging on a 1966 Yamaha YDS3?

soggydollars

Hey guys,
I'm looking for a little help with my yds3, any and all input is appreciated. First, I am by no means a bike mechanic
(bicycle, yes - motorcycle, NO) but purchased an old bike and am trying to get it running.
I like mechanical things, have some patience and a set of tools!

Here's the story:
I picked up a 1966 Yamaha yds3 (250 2 stroke oil injected), it had been sitting for 20 years in a basement and was in good overall condition with 18,000 miles. (all wiring is original, clean and intact with original ignition switch and key) It had a siezed piston and a gas tank 1/2 full of yuck.
I removed the heads, cylinders and pistons. A friend (2 stroke dirt bike mechanic) helped with cleaning the carbs (they were pretty clean to begin with) installed new bowl gaskets and upper rubber boots. I bought NOS cylinders, pistons, upper bearings, rings, gaskets, etc. and bolted everything back together. I removed and cleaned the gas tank and lined it with the Caswell epoxy tank liner. I also installed a new fuel petcock and all new fuel lines, clamps and inline filters. I removed the crumbleing air filter element paper from the unit and replaced it with a cut to fit filter foam and epoxied it all back together nice and neat.(not sure that it has the same flow as the original paper element) I also replaced exhaust gaskets, but could not get the baffles out of the pipes (kinda stuck, and didn't want to wreck them) exhaust comes out but not sure that they are not plugged up to some extent. I changed the clutch/tranny fluid. I cleaned the points (did not replace) and checked the gap. I removed and cleaned out the injection oil tank and filled with new oil. I also changed the nylon washers on the banjo fittings on the oil injection lines where they meet the cylinders. Installed new spark plugs and ran the bike on premix until I bled the injector pump and verified that it was pumping. Drained the premix and filled with fresh gas. I also installed a (NOS dry) vintage style 6v battery. (new acid and charged) I also disassembled, cleaned and polished just about everything on the bike, removed the wheels, cleaned and installed new brake pads. The bike looks great but is not running 100%.(makes a really nice garage ornament)

She started on the second kick (with choke) and I kept it running with the choke until I adjusted the idle (syncronized the carb slides by feel).
Once warmed up she idles just fine and runs pretty well on the stand, maybe a little boggy but revs pretty well with the throttle.
I have ridden the bike around the neighborhood, but it is bogging and is just not crisp.
The battery is not charging and runs down to the point that it will not start until recharged.
I pulled the plugs and one looks brown, the other is more black.
Tried adjusting the air mix screws a little but no improvment.
Any thoughts?
What do I try next?
Thanks,
Craig

MR.CHocko · Posted: Fri Dec 03, 2010 12:45 am Post subject:

From what you are describing it sounds like you are having charging problems. First get a multimeter if you do not already have one. Second get the bike running and while it is idling check to see what the voltage is on the battery. Your battery voltage should be 12.7 volts. If it is not reading that can either be your stator or your rectifer.

zjeppe · Posted: Fri Dec 03, 2010 12:50 am Post subject:

Hmm, he talked 'bout a 6 V battery Question

mixer · Posted: Fri Dec 03, 2010 2:52 am Post subject:

yeah its 6v from everything ive read.... and yeah theres probably a rectifier or bad regulator in there. MIGHT be the stator. however checking with a multi-meter across the battery should read 6.8 i believe. then its a matter of tracing where youre losing the volts.... check the regulator, check the rectifier, then check the stator, youll find one that isnt pushing right.
one thing ive had happen are you SURE you didnt charge the 6v with a 12v charger? i had a dumbass do that and COOK my battery, cause they volunteered to charge it at the store, and thinking THEY had a 6v charger i let them, cause i didnt have one. well... they didnt either. the joys of a chain store that hires people that DONT know bikes that well.

as far as whats going on with the bogging, lets see... brown... brown is good according to mr haynes.... black is not.... that means its too damn rich (drowning a plug is a good way to bog) turn the pilot IN by 1/4 turns wait 5 seconds between turns possibly even 10. thats ASSUMING its black sooty, and not black OILY....
black oily... you probably dont have the new rings seated right, OR the hone is bad.

oh and it helps if the carbs arent synched by "feel" just sayin.

MR.CHocko · Posted: Fri Dec 03, 2010 3:19 am Post subject:

I frequently get confused with the batteries as Honda went to a 12V for the Dream and the Superhawk in the 60's. Even tho I have a lot of Yamaha parts the YDS3 is a model I am not an expert on.

Bikegeezer · Posted: Fri Dec 03, 2010 8:10 am Post subject:

I wouldn't start chasing gremlins till you get the charging system sorted. The battery is small and will discharge pretty quickly with the alternator offline. That's a likely cause of all your problems.

Stu

soggydollars · Posted: Fri Dec 03, 2010 11:39 am Post subject:

Okay, cool.
I'll start with the battery/charging system and see whats what.
The 6v battery was a dry NOS that was filled and charged by a local battery mfg shop...
not saying they did it correctly, but I would hope so.
Thanks for the direction.

I also ordered NOS points and condensors as I figured it couldn't hurt to replace them.
Didn't install them yet, gonna have to make a tool to hold the dial gauge.

MR.CHocko · Posted: Fri Dec 03, 2010 4:48 pm Post subject:

You can get a 6V battery. If it is charging the problem could be the NOS battery. Most of the batteries for the Japanese bikes were made by Yuasa, so it should not be a problem to find a battery. Send me a PM if you think the battery is bad.