Hobbit Idle (or lack there of..)

Hello!

I gave my poor moped to a friend who is much more mechanically inclined than I. He took everything apart (engine,carb, etc) cleaned and replaced when needed (seals, etc)

I believe I now get more top end than before but no idle. We both suspect it is a timing issue. He did not have a gap tool and did not have time to check the timing. How easy/hard is this?? I have the hobbit's manual but I would like some feedback from yall (joew??)

thanks in advance!

-B

Re: Hobbit Idle (or lack there of..)

I started writing instructions about setting point gap .. but this is really an idling question.

Ignition timing / point gap that is close enough for the engine to run with good power is certainly close enough to get a good idle.

So, assuming the carb is clean and there are no vacuum leaks, first try this idle setting procedure.

In preparation, turn the idle mixture screw all the way in (gently) and then back it out 1 and 1/2 turns. The mixture screw is the one closest to the front.

You want it to idle when hot... so adjust idle only on a hot engine. First get the engine nice and hot.

:

Hop off and adjust the idle speed screw (it's the one that contacts the throttle linkage) so that the engine runs as slowly as possible.. lowering idle RPM till it almost misfires and dies.

Then tweak the idle mixture screw, turn it slowly in and/or out .. listening.. search for a place where you hear idle RPM speed up a little.

Leave the mixture screw at the point of highest RPM.

Go back to the idle speed screw and lower RPM again.

And again, tweak idle-mixture screw to raise RPM.

Repeat maybe once more..

By this time you'll know whether or not that thing is able to idle.. it _should_ idle if everything is clean and tight.

:

In my experience the lack of a good idle is due to either a "dirty" carburetor or a vacuum leak.. air leakage between the carb and engine.

In particular there's a tiny idle jet below that flat head screw on the carb.. And there's a perforated brass "emulsion tube" hidden in a cavity above the mainjet. They are often overlooked by people unfamiliar with the carburetor.

But these areas directly affect idle and, along with everything else, must be cleaned if a good idle is expected.

If it doesn't idle, ask your friend if he remembers dealing with these things.

Re: Hobbit Idle (or lack there of..)

I'm way past the fiddleing w/ the idle screws stage (but thanks for the input.)

I guess what my real question is how do I set my points? Is it hard? What do you all recommend???

my ped was "fine" untill my friend messed w/ the gaps and now its all screwy. Please help!

thanks,

-B

Re: Hobbit Idle (or lack there of..)

NEVER let anyone mess with yor ped...lolif engine runs timing is usually not the prob...crusty carb is usually to blame...clean it again!!!! use manual.......these things are VERY touchy! best of luck to you!

Re: Hobbit Idle (or lack there of..)

Spark happens right when the points contacts bein to open.. Electrical contact between them is broken and you get spark.

And this is supposed to happen as the piston rises and is very close to the top of it's stroke.

Notice the letters "T and "F" stamped on the flywheel.

There's also an alighment mark close to the flywheel's edge, on the engine case itself.. it's near the base of the cylinder.

Align the "T" with the case-mark. The piston is at the top of it's stroke.. Top Dead Center. TDC

Back the flywheel counterclockwise a little bit and the "F" will align.

This "F" alignment says the piston is a few degrees Before TDC.. BTDC..

And this is where Honda wants the points contacts to crack open and spark to occur. At the "F"

:

As a preliminary check, slip a piece of cigarette paper between the points .. a thin strip of ZigZag .. or rip open a cigarette.

Align the "T" (piston is at TDC)

The points should be open. The paper easily slides in and out.

Turn the flywheel countercloclwise. Watch the "F" mark. When that F mark aligns with the case-mark, the contacts should just close. The paper is now stuck.

Turn the flywheel very slightly clockwise and the paper is free again.

If this is the case, timing is really close .. double check it with a timing light .. i use this cheap inductive timing light connected to a spare 12V battery, while the engine is running.. works nice.

Setting Gap:

If the above situation is not the case, loosen the points hold-down screw.

Then use a flat screwdriver in the adjustment slot (to the right of that screw) to leverage the points body one way or the other.

Setting the maximum point opening (called the gap) also determines ignition timing.

And adjusting the points-body position (and therefore gap) is the only method available to set ignition timing on this bike.

Move the flywheel clockwise, a bit beyond the "T" mark.

Notice that there's a gap between the points contacts. Measure that point gap with a feeler gauge.

Gap should be around 0.35mm or so (0.014 inch)

Move the points body till this gap is about 0.35mm and tighten the points hold-down screw. That's it.

:

An alternative is to use a timing light. Adjust the points body and test with the light. Re-adjust if needed.

Search this forum or google for info about timing lights and how to make and use them.

Re: Hobbit Idle (or lack there of..)

Thanks joe w!

Re: Hobbit Idle (or lack there of..)

you're welcomed ..

if you really wanna thank me, check the timing and come back and tell me it's already on the button.. and that i wrote all that for nuthin.. so i can say "told you so" and will feel smug about it.

Re: Hobbit Idle (or lack there of..)

Take carb cleaner and spray around your intake and see if the idle changes. It is very common on these Honda mopeds for vacuum to leak around the intake. If that is the case: take the motor off the bike and remove the intake. Note which way the reeds go, up or down for future reference when you reinstall them. Take tack seal or preferrably some semi-hardening sealer to apply lightly to both sides of the reed. Don't get it on the moving plates! Reassemble and try it again. I have found this to be the problem on numerous peds.

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account