Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Thank you! I'm so bummed that the weather turned while we're here, but glad to be here!

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Whew! OK! Home and well. Old car did the drive great.

Just wired it up per Jeremy's diagram and it isn't powering the headlamp at all. My best guess is because there is no circuit at this point for that headlamp - it never connects to the frame ground or the ground from the stator:

https://www.mopedarmy.com/forums/file.php?7,file=239704

Next I'm going to measure power from the stator, BUT I know that without the reg/rect it powers the lights full blast, so I'm pretty sure that's not going to be the issue...

Re: Crazy Custom Frame Hobbit

🇮🇹💦 Of the Loin /

This is the diagram yall should use for all reg/rec conversations yes this is my own design patent pending and I shared it with the OP

20210323_092227.jpg

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Wiring is resolved and new intake on! Lowered the angle a bit and it seems to be doing well. Just need to finish up the jetting! Been taking it for rides and it's a blast, though it's still getting a bit hot.

PXL_20210401_171537577.jpg

Re: Crazy Custom Frame Hobbit

Glad you have been able to ride it. Can the timing be adjusted to resolve some of the heat issue?

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Timing is a good call yeah. I'm gonna try to test for an air leak again to see if there's one somewhere that I'm missing (maybe at the intake) otherwise it'll just be jetting/timing

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

OK, no leaks as far as I can tell. Bumped the timing to 23 degrees BTDC and I'm getting a TON more power but the idle is hanging suuuper high. I maxed out the idle jet at 52 and it's still hanging high. Dropping it to 46 it's either high or just dying (depending on my air screw). Thoughts?

Re: Crazy Custom Frame Hobbit

Raise needle (drop clip) to be more rich and drop idle jet.

Re: Crazy Custom Frame Hobbit

And make sure the slide is all the way as low as it can go. People forget that sometimes

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

ALRIGHTY!!!! I feel like a complete idiot, but figure out what was wrong. I was pretty sure there was an air leak somewhere but had tested everywhere for leaks. I pushed the carb around on the hose to see if there was a leak at the hose mounting and maybe a different angle would change things, or if it was caused by the carb not being completely flat (so I was pushing the carb to be flat), and suddenly the RPMs dropped! I tested again, wiggled again, and they didn't drop. Tested it again, and it happened again.

I started waving my hand over the carb trying to figure out what the hell was happening, and suddenly felt it pulling vacuum. It was the two fucking spigots at the top of the carb for the oil injection and vacuum petcock. I capped those, and it instantly ran perfect.

I need to rejet a bit more to get the tune ideal (it's a bit rich now), but it runs like a dream, has a ton of power, and holds 160 steady over about 45 minutes of riding. I'm just so so so so so happy.

Re: Crazy Custom Frame Hobbit

Oh you never capped them off.

Well that’ll do it

Congrats for not giving up

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Thank you thank you. Yeah, so much of this project was just "Colin forgot to do an obvious thing". Between the exhaust restrictor, carb spigots, and reg/rect wiring, these were all super obvious solutions that I went wayyyyyy too deep chasing other things because I'm an idiot and nobody thought I'd be that clueless, hahaha.

I honestly just assumed those spigots were overflow the whole time.

Re: Crazy Custom Frame Hobbit

Brandon Weiss (Detective brandon to you) /

That must have been so anger inducing and also relieving at the same time

Re: Crazy Custom Frame Hobbit

Should have just had me do it and saved yourself the headaches. Just kidding! Glad u got it figured out, hope you have fun with it!!

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

@Daniel you have no idea. I wanted to figure out how to transport it to Seattle so badly

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

OK, one of the last pieces for this little bastard is going to be dampening the vibrations from the engine. Right now it makes my butthole go numb pretty much instantly. I'm fine with the plates that hold the engine to the transmission not being dampened, just the parts that connect to the frame, which is a tube in the front and 2 plates in the back. Here are what the mount points look like:

PXL_20210415_183231521.jpg
PXL_20210415_183219840.jpg
PXL_20210415_183210086.jpg

Re: Crazy Custom Frame Hobbit

I’ve used all sorts of rubber stand-offs to stop vibrations. Just gotta decide how you wanna do it. Silicone or polyurethane damper sheets can be made with caulk, I’ve used car tire tread cutouts, etc. biggest trick is to find something that stops vibrations but doesn’t allow the engine to move too much (edited)

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Awesome. Do you think I need full motor mount bushings? Like, drill out the holes to larger and add material etc? Or can I get away with just some spacers?

For the front (picture below) I could potentially cut that tube that runs between the engine mounts shorter and add rubber spacers, but for the back the upright from the frame is sandwiched directly to the brackets holding the engine parts together. I'm not sure how to dampen that...

PXL_20210415_183205420.jpg

Re: Crazy Custom Frame Hobbit

You didn’t plan for this so it’s going to be tricky.

You could float your seat pretty easily though. How’s the bar vibrations?

If it were me I’d attempt to float the whole motor trans setup with full bushings. 2 in front 2 in back. Isolate the whole assembly from the frame as one piece.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Yeah I completely blanked on that. Gonna have to redo some work. I agree that the whole thing should be isolated - vibrations on footpegs are probably the worst right now, but more than anything I'm not stoked on the wear on all the metal parts from vibrating. That's gonna shorten the life of this thing like crazy.

Re: Crazy Custom Frame Hobbit

I once had a 120cc 2t engine on an aluminum frame scooter. Jesus that was fucked. Had to make a stand-off isolation plate with a full tire tread underneath to make it manageable. Car tire was what I had to use cuz any softer would deflect too much and throw the chain

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Mother of god I can imagine. Yeah I'm gonna hit up a machinist for the work on Monday. Thinking angle plate for the rear mount and bolt instead of weld to the bar that connects the 2 frame tubes at the bottom, and I can use a rubber standoff plate for that easily.

For the front, sadly, I think I'm going to have to get a new larger tube installed

Re: Crazy Custom Frame Hobbit

you should have your machinist bore out the holes for silent blocks like motobecane engine mounts

Re: Crazy Custom Frame Hobbit

A softer seat and foot pegs that are more off road style vs a solid chunk of metal. So it is more cage like and has points that touch your feet, vs a large flat surface your feet are on.

My garelli bikes vibrate a lot and more cage-y pedals help and their seats are super comfy.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Daniel yeah for sure. Going to be doing that with the motobecane engine mounts for the rear - the way the front mounts up, going through the engine as well, I think I need to change the frame tube instead.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Talked to the machinist and he suggested that for now I try to see what spacing the engine mounts with rubber spacers washers does, so we'll see how it goes.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /
PXL_20210520_005916003.jpg
PXL_20210520_194403821.jpg
PXL_20210520_194421025.jpg

Re: Crazy Custom Frame Hobbit

How’s it running

Re: Crazy Custom Frame Hobbit

Looks good for sure.

@Jbot One of my most non running bikes is also my prettiest. Ha!

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Runs great!!! Holds temps of 180 and rips around at 50ish, but gets up there in about a block. Tons of power - front wheel gets light every time I whack on the throttle.

Would be fun with a bigger carb and could use less vibration but it's a blast. I'll also probably change up the sprockets for higher top speed, because I think with the current setup all the power is at low rpm, but it's great.

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

Login or Create Account