What else could be causing the low compression
Re: 1982 Honda express won’t start
Re: 1982 Honda express won’t start
Your pictures only show so much. I do see some blow-by which suggests the rings aren't doing as well as they should. What does your compression measure?
Re: 1982 Honda express won’t start
> Captain Janeway Wrote:
> -------------------------------------------------------
> The thing where the piston sits? Cylinder? Again, get thee to the manual
> so you know what you're looking at. If you mean cylinder, sometimes they
> get stuck especially if they haven't been off in forever. You should be
> able to pop it off with the handle end of a rubber mallet or the like.
> DON'T just whack it from the side, you may bend your rod and totally
> screw yourself.
>
> You want to put in new rings, you might put up a picture of your
> cylinder so we can look at it. Make sure you have new gaskets, etc
> before you put it back together. Scrap off all that old base gasket
> material with a razor. Nice and clean. You want a good seal.
>
> Seriously look at the manual if you're not. It gives good direction on
> how to screw back on your head bolts (X-pattern), etc. I know I'm a nag
> about it, but it saves so many headaches.
You are not being a nag, just smart, I have the service manual for every bike I own, so even if I can't or don't want to fix it I can tell someone qualified what is wrong. It TOTALLY helps to have.
Re: 1982 Honda express won’t start
The compression is about 123 and is supposed to be 150
Re: 1982 Honda express won’t start
Can't tell by looking at them. They're cheap & easy to replace, so I'd recommend new ones. Maybe Give the cylinder a light hone too, if it's not a Nikasil plated one.
Re: 1982 Honda express won’t start
I’d clean the surface of the piston with some light grade steel wool or Dremel with carbon steel brush. Was your stator and coils all wet from oil? Not good that means your seal is bad which can cause low compression as well.
Re: 1982 Honda express won’t start
Yes, the stator area has oil inside of it and I just thought that it was supposed to be like that.
Re: 1982 Honda express won’t start
> Owen Sims Wrote:
> -------------------------------------------------------
> Yes, the stator area has oil inside of it and I just thought that it was
> supposed to be like that.
Bad seals give air leaks on these bikes too. I hope you have manual by this time. Note that seals on Left and Right sides are different sizes. You have to pull the kickstarter gear behind the variator to get at it, then pull with a 3 jaw puller. Make sure you put some kind of protection between the spike on it and the end of your crank, or you could split it (not kidding, I've seen a picture of it on here somewhere). People have different way of getting on the right side seals. most people just use some kind of pick to pull it. I'm using a paint can opener. Can get one free at the hardware store. Some of the techniques are on YouTube.
And yes, go ahead and change the rings. They're relatively cheap. If you can solve the problem with new rings it will save you swapping those seals (at least for now). As you can see, it's kind of a pain.
Re: 1982 Honda express won’t start
> Captain Janeway Wrote:
> -------------------------------------------------------
> And yes, go ahead and change the rings. They're relatively cheap. If you
> can solve the problem with new rings it will save you swapping those
> seals (at least for now). As you can see, it's kind of a pain.
I have to ask : Exactly how will new rings stop an oil leak to the stator ?
An oil wet stator will likely keep that motor from running .
The motor should easily run on 123 #s compression .
Re: 1982 Honda express won’t start
> P D Wrote:
> -------------------------------------------------------
> > Captain Janeway Wrote:
>
> > -------------------------------------------------------
>
> > And yes, go ahead and change the rings. They're relatively cheap. If
> you
>
> > can solve the problem with new rings it will save you swapping those
>
> > seals (at least for now). As you can see, it's kind of a pain.
>
> I have to ask : Exactly how will new rings stop an oil leak to the
> stator ?
>
> An oil wet stator will likely keep that motor from running .
>
> The motor should easily run on 123 #s compression .
Agree with the stator. I just want to see if he can get it running first. It doesn't sound like he's done a lot mechanically (unless I'm reading things really wrong), so fixing one thing might at least get him going.
I have one I'm changing rings on because it has low compression too. It's an easier fix after troubleshooting a lot of other stuff. If it still doesn't work I'll figure out where to go from there. You're right, it will probably end up being seals.
Re: 1982 Honda express won’t start
> Owen Sims Wrote:
> -------------------------------------------------------
> Yes, the stator area has oil inside of it and I just thought that it was
> supposed to be like that.
That's probably from an oil leak above the stator cover that somehow got inside. What bike is this again? An urban? If it's sticky like oil - the oil got in from the outside.
Fuel/2 stroke mix is not going to be like straight oil.
Maybe someone had the cover off in the past and slopped oil on it. (edited)
Re: 1982 Honda express won’t start
Temporarily , hose the stator down with a good amount of brake cleaner . Make sure you hit every connection good and any moving parts . If it has points , be sure to clean them well and check gap .
That may help get the motor running long enough to assess .
Good Luck .
Re: 1982 Honda express won’t start
> Captain Janeway Wrote:
> -------------------------------------------------------
> I have one I'm changing rings on because it has low compression too.
> It's an easier fix after troubleshooting a lot of other stuff. If it
> still doesn't work I'll figure out where to go from there. You're right,
> it will probably end up being seals.
My FA50 has just over a hundred pounds of compression and it runs nice . a bit weak , but ...
I'll be re-ringing it soon , too .
Re: 1982 Honda express won’t start
I have been looking at the manual online and saw this. What does foreign matter stuck in starter or starter gear mean? Also the battery that is on it is junk.
Re: 1982 Honda express won’t start
I started the moped yesterday and like usual it starts right up and runs fine but after like 30 seconds it idles high then dies and can only be stated by giving it full throttle and bogs.
Re: 1982 Honda express won’t start
is the carb still leaking gas?
Re: 1982 Honda express won’t start
I am not sure
Re: 1982 Honda express won’t start
Insure the exhaust is clean/clear and not partially clogged .
Re: 1982 Honda express won’t start
I have been looking for piston rings and think that it is just cheaper to buy the piston and the rings together. Do I have to do anything the the cylinder or head to make this work and is this good quality?
Re: 1982 Honda express won’t start
You might like this site : https://www.cruzinimage.net/?s=nc50
Re: 1982 Honda express won’t start
decent quality at both places. You'll want to hone your cylinder, check ring gap, heat cycle it at least once before riding. And new head and base gaskets after scraping/sanding off any old base gasket remains.
Re: 1982 Honda express won’t start
What is ring gap, heat cycle and how do you hone a cylinder also would I want the standard size piston instead of the oversized.
Re: 1982 Honda express won’t start
https://mopedarmy.com/wiki/Kit_break_in_guide
Look in wiki for other two. Wiki is really your friend here
Re: 1982 Honda express won’t start
> Owen Sims Wrote:
> -------------------------------------------------------
> I started the moped yesterday and like usual it starts right up and runs
> fine but after like 30 seconds it idles high then dies and can only be
> stated by giving it full throttle and bogs.
Do you really think that piston and rings will correct these symptoms?
Re: 1982 Honda express won’t start
That’s what I’m hoping
Re: 1982 Honda express won’t start
You may just need to adjust your carb. How many turns out is your idle/air screw? Should be around 1 1/2.
Re: 1982 Honda express won’t start
I got some better pictures. In the first picture is that the crank seal? Also I think that in the second pictures I’m pretty sure it’s the magnet thing and it’s bowing. And is there points on this because it doesn’t look like it.
Re: 1982 Honda express won’t start
In the last picture, is that bushing thing supposed to be snapped like that?
Re: 1982 Honda express won’t start
Is that bushing copper? It's not stock and no it shouldn't be split.
There are a couple of threads for parts in here. Should be able grab one cheap if you can't make one. If I had an extra I'd just throw it in an envelope for you. (edited)
Re: 1982 Honda express won’t start
Could that be causing my problem
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