Another poor runner!

[BR549]

87 Spree, this is my first one.

Got it complete and cheap ($100.00) put new battery, belt and tires on it and it looks near new.

Carb was filled with two stroke oil and it had sat up for a couple years. The case also had an abundunce of oil in it. Not sure if that was an intentional storage "pickling" or not, but I drained out the case, and overhauled the carb, checked the reeds and replaced the plug. I also had a burnt starter relay and replaced by using an AC clutch relay from a Ford Escort.

Per this site and the manual I have determined the bystarter works correctly, and the carb is completely clean but performance is still poor.

When running it will bog down, and act sluggish. However when it is stone cold, it runs great and seems normal for about a minute or so. It acts as if there is an air leak somewhere and it will not run unless the carb mixture screw is only 1/8th turn out. It idles fine, and mixture screw has little affect while idling.

Question, Are crankshaft seals as critical in this machine as in other two strokes? and What have I overlooked?

[fightingplankton]

However when it is stone cold, it runs great and seems normal for about a minute or so. It acts as if there is an air leak somewhere and it will not run unless the carb mixture screw is only 1/8th turn out. It idles fine, and mixture screw has little affect while idling.

make sure you're getting proper flow from the petcock.
if your fuel filter is clogged, this could lead to poor fuel flow which would cause it to not run smoothly.
if its not that, make sure the seal on your air filter is tightly fitted and the sponge is oiled.
if you're using an aftermarket filter, disregard.

normally i'd say its your mixture screw, but since you've ruled that out, check everything pre-carb(tank, filter, petcock, hoses)

[Flea_Biskit]

i would suggest the pilot jet is still clogged if it runs when cold the fuel enricher is on and when it is warm the choke closes which makes lean condion = poor running

just my 2 cent

[mousewheels]

Hi,
Welcome - great deal & good job working through the issues of a new bike.

The oil filling carb and crankcase is a symptom of an oil pump leaking. Might not cause a problem for you if you ride regularly. Keep an eye on how much it smokes after start up. The longer it sits, the more smoke. Eventually it will get enough in to the case to foul the plug at startup. But it might need to sit unused for months, so no need to replace the pump right away.

Crank seals are critical, but as Flea_Biskit mentions, the pilot jet would cause the idle air bleed screw to need to be closed more than std, and the bystarter does provide extra fuel when cold. Clogged pilot jet is a common problem with scooters that sat idle a long time.

[Wheelman-111]

Greetings:

Let me add my Welcome, and may I also add nice post? Thoughtful bit of diagnosis to bring it this far. Keep us posted; I'd like to read more.

I'm with Flea and Mouse on this one. Furthermore, faulty crank seals would betray themselves with some oily blow-out, especially if the case had filled with oil. Your post suggests that you'd have little difficulty pulling the alternator and drive faces for a look.

Given your quick work to date, I assume you've found all the carb-cleaning info in Tech section? A soft or very thin bristle held in a surgical clamp can assist scraping the resin out the idle "jet". See if you can spot the Legendary Pin-* O' Light. Just don't scrape so much that you alter its size.

[dooboz]

I have a question to go along with this topic:
I pulled my carb apart because it sat for 10+ years, i soaked the carb for 2 weeks in PB BLASTER to clean it up, I pulled the pilot jet pic up tube from the carb body and it is still plugged up i cant see thru it at all, it holes around the base of it that slide into the body but you cant see thru the lenght of the tube. Should i be able to do that? Do i need a new tube? and is that the "pilot jet" ? every thing else is clean and in good conditon. THanks for the help dudes.

[Wheelman-111]

Greetings:

Nice work so far. It sounds like your carb is the remaining issue. If the tube you pulled from the carb was behind the main jet, it's called the Emulsion Tube and does not much affect idle. Yes, it should be hollow and all those tiny holes need to be clear. However unless it is gouged or bent I do not believe you need a new one.

The pilot "Jet" is not a separate item but a size-controlled, cast-in hole in the carb body. It lives at the top of that other, smaller brass tube that lives alongside the main jet tower. Both the small brass tube and the hole in the base of the venturi need to be clear for the bike to accept throttle off idle. However confirmation of that patency can take some skill, the perfect light conditions, and usually a dose of mind-altering substance. Few have seen, none have photographed the Legendary Pin-* O'Light. It isn't a good idea to attempt to pull that pressed-in, thin-walled brass pilot tower out of the carb.

PB Blaster is more oil than solvent. Maybe a soak of, say... a hundred years in that stuff will eventually mobilize the hard resin that constitutes your clog. For faster action, may I suggest a more volatile, active smaller-molecule solvent like commercial carb Dunk, Acetone or MEK. Some say prolonged soaking can discolor the carb's bronze finish, but I do not believe that does any harm. Give it a swim for a long weekend, then set to work with a very fine bristle such as one plucked from a steel brush. Hold it in a surgical clamp of some sort and poke-poke-poke until all the gum is gone. Spray with carb cleaner and repeat. Don't stop until You See the Light!

[evilone]

I have a question to go along with this topic:
I pulled my carb apart because it sat for 10+ years, i soaked the carb for 2 weeks in PB BLASTER to clean it up, I pulled the pilot jet pic up tube from the carb body and it is still plugged up i cant see thru it at all, it holes around the base of it that slide into the body but you cant see thru the lenght of the tube. Should i be able to do that? Do i need a new tube? and is that the "pilot jet" ? every thing else is clean and in good conditon. THanks for the help dudes.

Good question, i'm pretty sure you're talking about the pilot jet and i pulled the same tube out of a trashed carb i had. I could not see light through mine either but the 6 holes at the base of it were not plugged. I tried sticking a fiber of one of them bristled brushes down it with no luck and i tried a skinny pin with no luck. Maybe i'll tank dip that for a few days and see if it is just plugged.