RD350 no spark/flooded

Hi all, bought another bike this weekend (not even finished the KE125
I bought last month) I may be addicted! Anyways, This is a 74 Yam
RD350 been sitting for a couple of years but everythings in good
condition (relatively speaking of course) the battery is new, I've
cleaned out the carbs compression is good, lights turn on etc. but
I''ve got no spark and Ive flooded the engine I think.

I've got power at the points, and resistance looks ok in the
primary/secondary and plug wires/caps. Do I need to replace the plugs
since I flooded them?

Also, I read somewhere that I will need to clear all the gas out of
the engine by putting a rag over the plug holes and kicking it over
until i get it all out, since I have oil injection will it be filling
everything with oil?

Thanks

 

It's hopelessly screwed up. You should sell it to me cheap. <G>

Ed Cregger

 

I had one of those new in 1974. The plugs could be a bit troublesome,
if they had the wrong heat range or the bike was driven too slowly they
used to oil and had to be replaced. Also, the ignition timing is
critical - I used to set it once a week.

Best to take the plugs out, kick the engine over several times to get
rid of all the fuel in the crankcase, and check that you have a decent
spark. You needn't worry about the oil, it depends on the engine speed.

Watch the front brake, the piston could seize on one side which makes
the wheel liable to lock, especially in the wet. It happened to mine.

Leon

 

Considering that the engine has being sitting without being started for
two years, it wouldn't hurt to replace the plugs and might even help
quite a bit.

It seems that in that era, motorcycle ignition systems didn't supply
very much voltage, I'm talking about only 9,000 to 12,000 volts here,
and the voltage rise time was critical. The voltage could leak away
across the oil fouled insulator faster than it could build up to make a
spark.

And, since the engine has sat for a while, it's just possible that
condensation has gotten up inside the park plugs. I've had plugs that
just mysteriously would fire unless I heated them up in a gas flame.
That points toward evaporating water from inside the plug.

With so little ignition voltage, the spark can't jump a gap that's more
than about 0.025 to 0.028 inches, the center electrode needs to be kept
filed flat so it has sharp edges that the spark can easily jump from.

And the small plug gap makes it harder for the fuel air mixture to find
the gap. In engines with more voltage, we were able to widen the gap
out to 0.032 to 0.035. But we were using automotive ignition coils we
bought at K-Mart. They produced 35,000 volts.

The condition of the ignition points is critical, too. They have to be
filed smooth and they have to be cleaned of any abrasive or residue
from your points stone or points file and they have to be accurately
gapped to about 0.014 to 0.015 inches.

Since the ignition gap on the stock coils is so small, the idle mixture
needs to be set fairly rich to start the engine. And your engine has
set without being run for two years. The idle jets are probably plugged
up and you will probably need to remove the carbs, open up the float
bowls and squirt aerosol carburetor cleaner through the idle jets, main
jets, and through the holes that the pilot air screws go into.

Before you remove the pilot air screws, turn them all the way
CLOCKWISE, counting the number of turns. Write that number down, then
unscrew the pilot air screws (keep them separate so you know which one
came out of each carb) and squirt aerosol carb cleaner through the
holes. When you reinstall the pilot air screws, screw them all the way
IN until they just stop turning, then turn them back out the same
number of turns that you wrote down.

If the engine is just mildly flooded, removing the spark plugs and
letting the engine sit for a while will allow the gasoline to
evaporate.

If the engine starts and you repeatedly foul the spark plug (it gets
all wet and oily), you may have to do all that kicking with the spark
plugs out. I've had float valves in the carburetors stick and the
crankcase filled up with gasoline. I had to remove the cylinder head to
pump all the gas out...

 

ok so i've got the flood taken care of now, had to pump it a bit, but
no major fumes coming out of there now. Went down to canadian tire and
picked up a bunch of new plugs this afternoon, but still no spark.

tried throwing my portable battery booster on the battery , still no
luck, but it may not have had a lot of charge in it either. Gonna
charge up the battery overnight and try it again tommorow after work.

there is voltage on the points, and voltage at between each of the
primary wires and ground. If my battery is weak could it be that
theres just not enough current to get the secondary up to 20kv or
whatever it takes for the plugs? Well I guess I'll find out tommorow
after I charge up the battery.

Also, i broke a couple of the old crusty fuel lines while I was
putting the cleaned up carbs back in, do I need to use special hoses
for that or can I just get some of that clear plastic hose from the
plumbing dept?

thanks again all

ps, if you've got any good web links to a site where I can learn about
motorcycles that would be great I'm a complete newbie and without a
little more knowledge I think I'm gonna end up wasting a lot of time
banging my head against a wall here.

 

You need to clean and gap your points to about .014 on the high side of
the points cam.

A really dead battery will suck up all the juice from a battery charger
and leave very little for the motorcycle systems if you're trying to
start an engine. The lighting load on a motorcycle is about 100 watts,
so make sure your headlight and tail light are off before you start
kicking...

Don't use clear plastic hose, you just start worrying when you see big
air bubbles in the hose and you'll be writing messages claiming the air
bubbles are keeping your engine from starting.

Use motorcycle fuel hoses. They are thin walled rubber hoses.
Automotive fuel hose is usually too thick, it will kink and shut your
fuel supply off.

 

It LIVES!!

got it working tonight, thanks for your help everyone, turns out that
the battery needed charging/contact cleaning and the new plugs and
away she goes, hard to believe that a 31 year old motorcycle that has
been sitting for 2 years will just run like that. All I really did was
clean out the carbs and charge the battery ( the old plugs might even
had worked)

Anyways, It runs, but I can't say how well. Being that I am a complete
motorcycle newbie in fact a complete engine of any kind newbie. It
sounds a little rough to my untrained ears. If I post a wma sound file
of it here (500kb) could I get your opinions?

Some groups have a no binary rule so I thought that I would ask first.

Thanks again everyone,

Now just waiting for my flywheel puller so that I can finish
rebuilding the first bike I bought a month ago (' 81 KE125)
and I've also got this RD350 "parts bike" to work on too... my wife is
gonna kill me I know it...heh

 

Vacuum hoses may look to be right, but don't use them. They will not hold
up to the constant exposure to gasoline. Go to the dealer and buy some
hose. List price is something like $1.50 a foot. The clear stuff at the
hardware store isn't good either. It won't hold up to the constant
exposure to fuel. It wouln't be nice if you were riding one day and you
notice a leak and discovered that the new hose has started to dissolve.

rj

 

alright guys here it is, got a small website up now, have a listen to
my rd350, and I promise to put up some pics of it and my other project
bike soon.

thanks,

heres the web addy: http://members.shaw.ca/jchihonik/

 

Yep, sounds like and RD350 to me You could have given it a bit of a
rev for us...

Brian

 

wanted to wait for some input first, didn't want to rev it up and blow
something that i didn't hear. neighbour might get mad if I start
revving right now (it's right outside his kids window ) but I'll run
it up a bit tommorow after work and put that up on the site with some
pics. Whats an acceptable rpm to rev it up to?

 

It sounds really good, Monk.

If you really want to give the troops a thrill, after the bike is repaired
to your satisfaction, mount the recorder on the biker and go through the
gears for us. That will "really" bring back the memories.

My 68 Yamaha 350 twin wasn't the RD-350. It was slightly before that and
utilized a stamped steel frame. I used to call it the "Whaleback". But the
engine sounded the same and it would haul ass. Loved that bike. I traded a
guy a new guitar amp for it. I've felt guilty ever since. Another friend of
mine borrowed it and totalled it. I guess that was instant Karma.

Ed Cregger