MOPED ARMY

I hadn't even got to doing a plug chop yet. This was it's first voyage with the new carb. I did let it get up to temp before letting him take it for a spin. Did not seem to be running to hot and the exhaust seemed fairly rich. So I wasn't too worried about seizing her up. I'm hoping it is only top end. I'll pull the head once I've allotted myself the appropriate grieving time and quit being angry about it. From the sound of it, if the rings are shot, it certainly sounds like pieces of them may have made it down into the crank.

The piston still moves but, feels VERY rough when carefully cranking her over. I dare not crank her over anymore until I pull the head and see whats going on. How do I determine if she is in fact running too lean if there are now adjustments on this carb? I should probably be running a temp gauge. But like I said she didn't smell or feel too hot and the exhaust had what I consider an appropriate amount of smoke.

The stock was an Encarwi H12. I could never get that thing to run right. The new carb is a Delortto SHA 15.15. No air/fuel adjustment. Only a main jet. It has a lever-style choke and only one main throttle slide. I bought an array of jets to go with it. However, the one that came with it ( I believe is a 62 or 65) seemed to be operating pretty well.

The jet that came with it is either a 62 or 64. My intake at the head has reeds and a factory spacer which I left intact. The carb side has the correct shim. I pulled the one out that came with the carb. Was a bitch to get out. I did NOT put an O-ring in there. But, I did test with carb cleaner for air leaks. There was no change in RPMs.

Regardless, pretty simple engines. Pull the cylinder and feel the crank directly for slop and roughness. You might have gotten lucky and just seized your top end in which case it won't be a huge deal. But if you did seize the crank. It's a bit more work to rebuild but not a hard job.

Most likely you seized the bottom end bearings, that sound your describing points in that direction. Soo yeah, spliity time.

If you seized your top end, it doesn't necessarily mean you broke the rings.

You will know once you pull the head and cylinder. If it's the bottom end, spinning the crank manually will feel chunky, gritty...etc..should be buttery smoothe. If it's the top end...well you won't overlook it.lol

Like I said I think I was running at 70. .there's probably an entry in the wiki with jetting info though.

Yes I feel like 68 or low 70's is going to be the jet for that carb on a stock setup.

Get an o-ting in there. The cab has to have it. I respect that you had checked for an air leak and did not detect one, but I am still going to advise putting one in. I bought a little o-ring kit from harbor freight for like $5. It comes with all kinds of o-ring, one of which is perfect fit for the sha intake area. They sell a specific formed o-ring for sha, which I have had included in the two 16:16 sha that I have purchased.

Dont be discouraged even if it is something that could have been your fault. Just a learning experience. It is just a moped after all.

Let me tell you how much my immediate neighbors hate me because of all the tuning runs in front of my house.

No, put the shim into the carb. The press the o-ring into the shim. It gives a rubber mating surface fully around the circumference of the intake manifold, so the whole round end is sealed to the carb

The shim fill the space around the intake so it can clamp on, the o-ring is smooshed between the intake and carb throut.

Wouldn't worry about it untill you diagnose your problem tho...it could also be a Piston pin clip that flew out and trashed the cylinder.

No on aaron with the oring. If you have tour carb off. The oring goes in to the intake mou ting area first. The shim I never remove from my intake so I never consider it a part of the carb. I consider the shim part of the intake. So basically the oring is sandwiched between the carb body and the plastic shim. The oring will seal off the clamp gap on the carb body.

I was wondering the same thing, if it was just time for the bearings to fail. The moped sat (with the previous owner) for approximately 7 years with no fluids in it. I, of course, checked it before running. I'm currently running ATF Type F in there right now. I'm not 100% sure if that is correct.

I've seen this list from Vintage Mopeds. Thanks so much for providing the link. I have a buddy who works in sourcing bearing so, hopefully it is relatively easy to find them all. I've done pretty much everything to this bike except for the breaks and splitting the bottom half. I'm a little apprehensive about it to be honest...lol. I've read up on it some. Is heating the case to over 200 degrees paramount? Or is that just to facilitate removal of pressed bearing, etc.?

And yes, definitely going to start high on the jetting and work my way down with ample amount of plug chops. Thanks for the input!!! I'm going to pull the cylinder this week and check out the top end. If she looks okay, I'll start tearing into the lower end. Do you think my gears are okay?

if its crunchy when u turn it by hand you gonna have to forget about the jetting stuff and do a full rebuild.

My bearings could have very well just been ready to shit the bed. The ped sat with the previous owner for 7 years dry as a bone with no fluids in it. I checked everything as best I could before running her (without splitting the case of course). The plug chop (post incident) actually looks great. Nice dark tan/milk chocolate. So, I'm not so sure she was running too lean. I also performed air leak checks after installing the new carb. The air leak check was good. I'm certainly not opposed to the o-ring thang. I'll give it a shot when I rebuild her (in the cooler months because its too damn hot here). For now, I got an '08 Tomos running pretty well for the kid.