MOPED ARMY

Ah man I just wrote this on that thread about the eurokit, then I was like 'nobody wants to hear an old man ranting about low compression' so I didn't post it.

Yeah especially on big over square setups, I don't really have a good reason to explain it but I'll think about it. It seems like on the hobbit and v1 especially, with the 47+ mm kits, letting them get through the lower rpm with lower load and bmep.

It's always better for the combustion process to get an earlier spark event and have everything fully burn, I think the short stroke makes things happen faster, and it takes longer to propagate the flame front across a bigger bore, so lower compression kinda softens things up. Makes it so it's not so violent when it does hit, so instead of putting all that extra heat into the piston and head and detonation, it's pushing the piston down. You can kinda feel it like smoothly building pressure on each hit rather than slamming hard, maybe? Maybe I'm nuts? I don't know.

Big dome, tight narrow squish, like less than 40%, push the timing as hard as you can and pound fuel to the fucker, sure to blast.

just wick the heat same achievement

Yeah heat= power, you can get rid of it faster but you're just getting rid of more energy that should be pushing your piston down.

Gotta keep as much heat as you can inside the power cylinder and prevent it from escaping until it's done it's job.

Meh, you aren't a giant windsail the low compression setups never get me where I need to be

Single speed is real moped everything else is just scooters

Plz tell the robots

150 PSI (technically it's 148 or 151 I think) is 10:1 compression ratio

220 PSI is running a 14.6:1 compression ratio.

I've never really measured compression, Angel just kinda showed me how to guesstimate compression one time for the low side so I just use that to eliminate compression when diagnosing a no-start situation

I haven't ever modified a head except for a Batavus Bronco I got from a dump and would sand a puch head down on a cinder block the Scuba Steve way to regain compression when the blown out rings inevitably lost more slowly.

I'd say a Gila on a V1 is generally like 185/190? I think that's a good some but you do need to manage heat in high load situations. Gila does good at surviving heat tho. They do blow head gaskets so there's that

10 years agoi used to run 210 psi for short spells (holed a piston) but then settled on 150psi as my target. 2 years ago i reduced this to 135 and this year im happy with 120 on my moby. (still wont pedal start)

must be an age thing...

wish my blood pressure would come down with age... (edited)

I took a standard long hose compression checker and took off the crimped hose connectors to reveal a hose barb underneath.

Cut hose and then hose clamp. I also don’t use the brass extensions it came with. Schrader right into the jug.

i borrowed 4 gauges off a local bike repair shop and tested them alongside my 2.

2 of them read identical and 2 got thrown away. so much difference. the best two were old school gunsons from the 1980's

the newer gunson available on amazon was way out.

Test before and after the 'conversion' .

Post the results , please .m;)

Duh I already told you. 20% diff approx.

Here’s what I did it’s fine

I’m going to try this with the hose one I have 🤙🏻 Thanks for the pro tip.

Wtf…odd double post

I got the stens compression tester coming.

funny it wouldn't work from the link you put up there...maybe it'll work from this one?

https://maverickmowersupply.com/752311-compression-tester-?search=stens%20tester&description=true

anyways, it'd be cool if all the people who did this stuff seriously all got the same tools so we could share results between each other and know that we're all talking the same language, if you know what i mean

Pressure = force/volume.

More volume (longer hose) creates false low reading.