Re: Moroni MO2 spark issues

IT'S RUNNING YA'LL! Swapped the bunk coil and she started but quickly died. Went back with a brand new plug with even better spark and it ran. Even idled after a 1/2 ass carb clean. Petcock is super weird I'm not used to frame tank and like a 1" fuel line and the petcock stops in like 4 positions. I have flow though. Runs on choke then wants to be off choke but dies when trying to ride and never gets over like 5 mph. I'm happy for now and will continue when I have motor time. Tips and advice from here?

Re: Moroni MO2 spark issues

Carb's still not right. Choke pulls fuel thru clogged jet or passages. More work to do.

Re: Moroni MO2 spark issues

Absolutely Don glad you chimed in. Just stopped more than happy it was running. Smokes like a mutha too. Time to clean idle jet, did a bunch of reading on the dellorto...weird carb. :) I rode it, it idles but didn't do more than 5mph, in snow. Hit me with the advice from here man! Oh, guy made his own "baffle", think I should cut that off I have no idea what it consists of

Re: Moroni MO2 spark issues

When you let that choke up, you need an airbox for SOME restriction. Makes it run smoother.

Re: Moroni MO2 spark issues

I've got the stock filter and airbox mounted.

Re: Moroni MO2 spark issues

Good. Gotta hit the sack now.

Re: Moroni MO2 spark issues

So the bike is running and rideable just curious of what feedback I get on where I'm at. Ran and idled, smoked like crazy and went maybe 5 with me on it. Drained the tank and put fresh mix in. Less smoke and runs better but after 3 carb cleans I've probably hit 8 mph. Revs hard when on stand, just doesn't go when I'm on it. Has tranny fluid but may be auto trans fluid. Manual says it needs sae non detergent 20. Throttle cable seems okay and I tried just yanking on it while riding, no difference in top speed. Stock air filter and box are on it, fiddled with that, none and it dies, more or less it wants it on. Thoughts now are maybe a $20 replacement 14/12. What are yall thoughts? Clutch? Trans? Thanks guys

Re: Moroni MO2 spark issues

Did you ever check the exhaust port and exhaust pipe aren't stopped up? Just a thought.

Re: Moroni MO2 spark issues

Solid thought Don, I forgot to mention that was one of my ideas also as the previous owner 'made his own muffler' or baffle, it's clear looking into it but I'm half tempted to just cut it off. Or should I detach at motor and see how it runs that way? Eventually I'm gonna put a decent exhaust on it but am trying to get it dialed in somewhat first.

Re: Moroni MO2 spark issues

The previous owners sweet home made baffle was pretty much not sweet at all. Almost completely sealed. I'll attach a pic. I popped that off, filled a fresh tank of mix, drained the auto trans fluid and replaced with sae20. Loud as hell of course but with a bit of tweaking the throttle cable at carb was able to pull a whopping 18mph. Felt like warp speed compared to 5. Also makes sense why it would smoke from every orifice not just the usual 2 stroke smoke or shitty old gas. I think the MO2 should be hitting 30 tuned right so is it a safe bet that the rest of what's left of the exhaust and/or exhaust port is clogged from him running that baffle sending exhaust back into the engine? I could clean the carb for the 4th time or is it time for a $20 repop carb too?

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Re: Moroni MO2 spark issues

Piston may be pretty bummed up. Rings stuck. Checked compression with throttle open?

Re: Moroni MO2 spark issues

No sir. How would I go about that? I can tell you it revs to high heaven on the stand but just won't get after it under load. That 'baffle' wasn't completely closed off but damn near, I can't believe he ran that.

Re: Moroni MO2 spark issues

> BBD 83 Wrote:

> -------------------------------------------------------

> No sir. How would I go about that? I can tell you it revs to high heaven

> on the stand but just won't get after it under load. That 'baffle'

> wasn't completely closed off but damn near, I can't believe he ran that.

Just get a compression tester,screw it in spark plug hole, open the throttle and kick it over a coupla times. Read the gauge. Do it again and compare readings.

How clear was the exhaust port on the cylinder where the pipe hooks up?(edited)

Re: Moroni MO2 spark issues

Sounds good Don, I haven't taken the exhaust off yet, will check the port tomorrow and report back. Thanks for the continued help!

Re: Moroni MO2 spark issues

You're welcome! We gotta have ALL MO2s running like scalded dogs! LOL!

Re: Moroni MO2 spark issues

Alright Don since you're the only one who cares about my Morini haha...I pulled the exhaust to look at the port and to my surprise it's not gunked up. Looked pretty clear. I was able to run something through the pipe too (what's left of it) so it's not clogged. It's really just a dump pipe/header so I'm sure it has no back pressure. I'll attach pics of the port and leftover pipe along with the epic 'baffle'. Wasn't able to get a compression tester yet but I'm gonna guess it's below 100. We'll see, you're the expert. Would that pipe having no backpressure be my 18mph culprit? Still could be carb/fuel issue but I'm super anxious to see a compression reading. It's 10 times easier to kick over than my Hobbit (with decomp) if that's any indication.

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Re: Moroni MO2 spark issues

Here's the rest of the pics...

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Re: Moroni MO2 spark issues

Um, thats a 5+ horse lawnmower engine muffler. Those were designed for four stroke motors too.

Re: Moroni MO2 spark issues

Ya I know, I can't believe the previous owner thought that was a good plan. Mind blown, it's literally about as close to completely sealed as you can get.

Re: Moroni MO2 spark issues

> BBD 83 Wrote:

> -------------------------------------------------------

> Ya I know, I can't believe the previous owner thought that was a good

> plan. Mind blown, it's literally about as close to completely sealed as

> you can get.

At least you know better. You have to be a detective with previously owned vehicles.

Re: Moroni MO2 spark issues

Get a decent pipe for the MO2. That'll help, but check that compression. 100 psi is okay. Not good, but okay to run. Don't run it without a pipe to keep cold air from returning to a super-hot cylinder.

Re: Moroni MO2 spark issues

I could slip a jammy chamber on for 50 bucks from 1977mopeds. Any recommendations? I'm trying to get it running decent for cheap and then go from there. I only have 150 into the whole bike. I'm getting a compression tester tomorrow. . .

Re: Moroni MO2 spark issues

♣Slew Foot♣ /

Pipe generates up to 30% of the up get a decent expansion chamber that goes with the carb.

Re: Moroni MO2 spark issues

> live ɘvil Wrote:

> -------------------------------------------------------

> Um, thats a 5+ horse lawnmower engine muffler. Those were designed for

> four stroke motors too.

I'm sure you all know this , but , that muffler should have plenty of flow . It has a 'redirection' plate inside , so you probably wouldn't be able to see straight through .

2 or 4 stroke , doesn't matter . It's designed to quiet exhaust .

That straight pipe obviously isn't the best for performance . In the early days of 2 strokes , that's all that was used . That and a muffler , much like the one the OP removed .

I'd bet that if the OP poured about anything through that removed muffler , all but a few drops would come out the other end , in a hurry .

Re: Moroni MO2 spark issues

> Don Ohio Wrote:

> -------------------------------------------------------

> Get a decent pipe for the MO2. That'll help, but check that compression.

> 100 psi is okay. Not good, but okay to run. Don't run it without a pipe

> to keep cold air from returning to a super-hot cylinder.

If its really down on compression, there are ways to get that back up some (temporarily) without re ringing or rebuilding the motor.(edited)

Re: Moroni MO2 spark issues

Did compression test and it tested at 90. Not amazing but way better than I expected. I did the test with throttle wide open and the exhaust is still off. My Hobbit runs pretty damn good and it also tested at 90. So...what are ya'lls thoughts? I need to get a pipe regardless so trying to decide on spending 120-150 or just spending 50 on a jammy slip on. Again just trying to get it running good before I go hog wild dumping money into it. I'd probably get a couple mph gain from airing up the damn back tire but that puts me at 20. Repop dellorto? Recheck timing/point gap? What about clutch/transmission?

Re: Moroni MO2 spark issues

Richard Eberline /

If rust or paint is on the surface and under your ground wire, you will have no spark. The orange external coil's cap or wire may be loose. Also if that cap has 5 or 10k ohms of resistance and you have a resister spark plug (3k). A lot to overcome and old points to boot. . 016 gap on points. stator plate in the middle and a good ground.

Re: Moroni MO2 spark issues

Thanks Rich but got all the spark issues figured out, on to getting more than 18mph now per the thread.

Re: Moroni MO2 spark issues

Now that the issue is not spark related should I start a new thread or will I get bitched at for starting a new one on the same ped?

Re: Moroni MO2 spark issues

Man, I was looking at the head to cylinder connection and it looked like too big a gap, maybe too thick of a gasket.

I'd probably slip the cylinder off the piston and give it a good look for broken or stuck rings and scarred cylinder. Shouldn't be a thick gasket on the head to cylinder joint. A thin piece of copper sheeting is all you need for a gasket. Some engines don't even put a head gasket on there.

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