Re: Crazy Custom Frame Hobbit

For $300, you could buy enough sheet metal to build 50+ tanks. With that much practice, you'd be an expert.

Re: Crazy Custom Frame Hobbit

^

Re: Crazy Custom Frame Hobbit

Some people don’t have time to build 50 tantks

Re: Crazy Custom Frame Hobbit

> Daniel '' Wrote:

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

> Some people don’t have time to build 50 tantks

Don't we make time to do what we want to do ?

Re: Crazy Custom Frame Hobbit

> Daniel '' Wrote:

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

> Some people don’t have time to build 50 tantks

Spend a day or two ruining some sheet metal till you get the welding technique down, and the after that it's easy.

My first tank (and pipe) was a bird shit weld covered piece of crap. My second was a little better. My fifth only had a few pinholes due to mig gas bubbles, and Caswell sealed her right up.

To me, it's all about the DIY.

But it's your bike, your money. I'm just relaying my experiences.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

I dig that, and am pretty tempted, but honestly my bends were utter crap and the wire-feed mig kept tripping the breaker so I could only get about 1/4" of a weld before having to stop. I think I'll go for it for the next iteration of the tank, but it's a weight off my chest to have my shop be not full of steel dust and splatters. Also, the biggest difference is that the machinist is willing and able to do angles and bends that I wouldn't be able to do at all.

If it were just replicating my tank that I buggered up I would go for it again, but he's going to be able to radius the rear of the tank and put a taper on the whole thing towards the back.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

New design for the tank!

ScreenShot2020-12-15at11.33.33AM.png

Re: Crazy Custom Frame Hobbit

> Colin Ratcliff Wrote:

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

> New design for the tank!

> >

They call it, the crotch annihilator. Those corners tho.

Re: Crazy Custom Frame Hobbit

> Aaron Goldman Wrote:

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

> > Colin Ratcliff Wrote:

>

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

>

> > New design for the tank!

>

> > >

>

> They call it, the crotch annihilator. Those corners tho.

Just a little padding and it will be fine. The only time I have issue with an angular tank is if you have to widen your legs more than you do for the seat, then it becomes more of a pinch point then.

Re: Crazy Custom Frame Hobbit

If you're gonna go basic on the seat pad, harbor freight has construction kneeling pads for 6-7 bucks that work great. Way better than a squishy yoga mat.

56572_W5.jpg

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Oh damn, good call on the HF! And the back of this tank will be less wide than the frame rails, so I think it'll be okay. Hard to tell but all the corners will also be rounded. I'll probably grind to round even more

Re: Crazy Custom Frame Hobbit

Here's mine after cut and shaped. Used spray on contact cement to glue it on. Ran it at the track a few times. Works great, doesn't compress and flatten out and bruise your inner thighs like the yoga mat did mine.

IMG_20201220_144055.jpg

Re: Crazy Custom Frame Hobbit

Tweaker trash /
7C850282-2D6A-450B-93F9-834F5A172065.jpeg

Re: Crazy Custom Frame Hobbit

Tweaker trash /

Fuck this I’m going shittercarting

Re: Crazy Custom Frame Hobbit

Tweaker trash /

Thanks for the idea 😂

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

https://photos.app.goo.gl/EvW9Y8jVAdaCJ7WY6

Seat needs to be cleaned up, but the bike is together!

Video here:

https://photos.app.goo.gl/PYbuofBh7uRVg6zTA

Starts and runs great. Can't rev high enough to actually grab the clutch at the moment (red springs), but I'm pretty sure it just needs to be richer (currently at 210). Might do a leakdown test as well. Might also have some fuel flow issues - I'm worried that the fuel switch I'm using is too small. Pretty sure the actual spout from the tank is big enough (1/4"). (edited)

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Alright all, I'm at a complete loss and need your advice. I will test anything you tell me to test and try anything at all.

I'm completely at a loss - I feel like I have tried everything and I am usually able to figure out what's up with the running issues

It idles okay, and starts right up, but it won't pull with any power at all. Current setup is:

Malossi Liquid Cooled Kit

HPI Ignition

TJT Variator

Red Springs

VM20 with 180 jet

One way bearing

BR7HS plug

I have:

-jetted everywhere from 110-210, seems to run a little better at 110, but still can't rev very high or with any power

-changed to blue springs - it will then grab, but won't variate, and I can stop it from spinning by hand (engine will still run, clutch just disconnects)

-done a leakdown test - almost no loss at all (still in "set" not even at 20% loss in green)

-cleaned the carbs and verified that the floats aren't sticking

-plug seems pretty clean. Not super sooty or anything

A couple things I noticed and checked:

-it would lose power after a few seconds at WOT. I switched out the fuel switch for a different one and that resolved the issue.

-it would slowly drip fuel at the overflow for the carb, and also seemed to run better when I turned the fuel off for about 10 seconds and kept revving it. This is why I checked the float. Fuel drip seems to be gone after checking the float but the other issues are still present.

-sometimes it will die after a long period of WOT. Haven't figured out why.

Video of it running with a 180 jet here:

https://photos.app.goo.gl/GujtqaFuN3EwN7Tp7

Re: Crazy Custom Frame Hobbit

Sounds Ike you’re pig rich or you’re timed super retarded. Did you check with a timing light? (edited)

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

I'm gonna check timing next - that's a great idea. Also I'm running a big ol doppler moby pipe.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

also, can you check hobbit HPI timing with a timing light? I always check by piston distance from tdc. I don't think they go by degrees

Re: Crazy Custom Frame Hobbit

There’s got to be a way to confirm timing with an inductive light

Re: Crazy Custom Frame Hobbit

Joe Schuitema /

Mount some kind of pointer on the cases so it almost touches the flywheel. Use a piston stop to find tdc. I use my adjustable one so it just touches the piston, then rotate the crank both ways and split the difference between the marks. Measure circumference of the flywheel and divide by 360 so you can put timing marks at 10, 20, and 30 degrees using your calipers. Now you can use a timing light and see what your actual timing is at. I'm guessing your timing is around 5-10 degrees. I've had points ignition mopeds idle great at 5 degrees but wouldn't get over 15mph. Bumped up to 16-18 degrees and back to 40mph.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Cool! Yeah this will work to determine the current setting, but as soon as I adjust it won't work, because the crank position relative to the flywheel will (ostensibly) change. I set it to be about 2.5mm BTDC, but obviously that changes with the stroke of the cylinder. I'll test out this way today!

Re: Crazy Custom Frame Hobbit

Joe Schuitema /

It will only change if you adjust the timing by moving the flywheel. I assume you're moving the stator.

Re: Crazy Custom Frame Hobbit

You remark the flywheel every time you pull it and out it back on in the new tdc spot

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Ohhhh duh! I always take the dang thing off to adjust timing. Forget that you can adjust the stator a bit as well

Re: Crazy Custom Frame Hobbit

Tweaker trash /

> Colin Ratcliff Wrote:

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

> Ohhhh duh! I always take the dang thing off to adjust timing. Forget

> that you can adjust the stator a bit as well

2mm before tdc! Set it and forget it, put the Mount screws in the middle of the slot so you can evenly retard and advance or just go for advance only with the screws all the way to the left of the slots

Re: Crazy Custom Frame Hobbit

Tweaker trash /

/description (edited)

Re: Crazy Custom Frame Hobbit

Tweaker, you got a big place to ride around.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Update:

Confirmed it wasn't the timing - appears to have been about 30 degrees BTDC, so I reduced it and it didn't change anything

Took off the intake and noticed that there was a TON of fuel resting there. Not sure how best to resolve, but I also noticed the intake wasn't super torqued down (possibly due to the gaskets compressing), so I torqued it further and am going to reinstall today. Wondering if maybe it was the gasket on the other side of the reeds, and it was somehow blowing back fuel?

Either way, the symptoms definitely point to it being too rich - particularly because it seems to run better when I turn the fuel off for a while. If it still persists after I've reinstalled the intake I'm going to check piston direction.

Any advice for next steps after that?

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

Login or Create Account