Re: Crazy Custom Frame Hobbit

Ok. So I’m a touch late. It happens to the best of us. Maybe a downdraft?

Like this carb for a Honda.

I know it’s not a performance thing but it is something. Maybe twin cable-actuated carbs? Cause that wouldn’t be a pain in the ass.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Downdraft is a cool idea, but I think with the polini I can get it a bit shorter.

I'm also definitely planning to change the engine angle in the future.

Updates! With all the snow here I kinda put off working on it for a couple weeks, but got at it again today:

1) upped the pilot jet for the 52 and it seems super happy, though for some reason I can't turn the idle down enough to kill it - I thought there was a vacuum leak somewhere but can't find one. I don't THINK the angle of the carb would cause this, and when I take it off and angle it to the same angle as it's mounted, there's no fuel leaking.

2) there's something off with the wiring, which is causing it to not get nearly enough power. The headlight is suuuuuper dim, and the water pump won't work when the headlight is on. This is with the trailtech reg/rec. I'm wondering if it's only putting out 6v or something.

3) I'm pretty sure there's a head gasket leak into the water jacket - when I disconnected the water pump and revved it up, it looks like it's bubbling like crazy in the radiator. I'm not 100% sure that's not just a result of all the vibration.

4) I tried torqueing down the head further, set my torque wrench to 8.5, and snapped one of the studs. Thankfully I use cylinder studs instead of bolts, and it snapped at the head, so I just have to wait for new ones to come in from treats, and it didn't damage the case or anything.

SO, I ordered new studs from Treats, also ordered new gaskets, and once those come in I'm gonna try to figure out what's wrong with the wiring, and tune the jets.

Also gonna hit up the auto parts store and get some bent intake hose to mount the carb at a more level angle (right now it's at like 30 degrees or more)

Re: Crazy Custom Frame Hobbit

Totally normal JBOT /

Nah you’d know if you had radiator fluid crossing.. white smoke everywhere.

That’s just water cavitation. A powerful pump just does that on mopeds and water gets crazy looking even without (edited)

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

White smoke from the exhaust, right? There was some vapor from the radiator too but probably because it was 180° and freezing out

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Anybody have any idea why the wiring would be doing that? I'm not familiar enough with the Trailtech Reg/Rec

Re: Crazy Custom Frame Hobbit

Totally normal JBOT /

Are you running hpi or something else?

Do you have a multimeter?

Do you have a solid ground to frame or are you floating ground

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

HPI, solid ground to frame, I do have a multimeter - I'll check current once I get those studs in and fire it up. Wiring I'm using is:

> Black - Ground (- side or ground)

> Red - Capacitor/Battery and lights (+ side)

> Red/Yellow - Not used

> Yellow 1 - input AC current coming from Stator

> Yellow 2 - Also Ground

> Wired up my pinto this way there was no need to float the ground. Voltage stays regulated around 13V - 14V (adjusted) with no issues.

Re: Crazy Custom Frame Hobbit

Totally normal JBOT /

No rectifier? You need a rectifier

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

oh this is with the trailtech reg/rec

Re: Crazy Custom Frame Hobbit

Totally normal JBOT /

Is your battery low? What voltage do you see coming out of the rectifier

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

No battery, just a capacitor. Once the new studs come in I'll check current!

Re: Crazy Custom Frame Hobbit

I see you’re not running a battery, but I figured I would post my diagram to at least get you an idea of where to go. Note that all grounds after rectification are floated, or connected to the negative terminal of the battery. It also doesn’t show it, but the ignition is grounded as directed from factory. (Hpi mini rotor)

C9786F4D-4AE4-44DB-88EB-E9108A9B40BC.jpeg

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Yeah I'm thinking I need to float the grounds on this - that's what the trailtech site says for this part. Just saw the comment on Treats and was hoping to get away with not floating it.

Re: Crazy Custom Frame Hobbit

Totally normal JBOT /

On standard hobbit stators I never float ground and it’s never been a prob, but I don’t fuck with hpi so....

Re: Crazy Custom Frame Hobbit

Tweaker trash /

You need a battery

Re: Crazy Custom Frame Hobbit

Tweaker trash /

> Tweaker trash Wrote:

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

> You need a battery

Edit: try disconnecting the water pump!

Re: Crazy Custom Frame Hobbit

Totally normal JBOT /

What pump are you using?

Bosch pumps pull about 1-1.5A at 12v

Re: Crazy Custom Frame Hobbit

It’s just like Jeremy posted. You don’t need to float the ground on the hpi, only have to do that if you want to run ac and dc. To have the whole bike on dc all of your grounds need to be going to the black wire on the the rectifier, which to run dc needs to be hooked to the capacitor/battery (-) and not the earth ground.

Re: Crazy Custom Frame Hobbit

The lighting coils I have seen on a HPI are tiny, what is the Watt output of a HPI?

I know with 55w on an MVT on a scooter at low RPM the lights flicker like crazy. This is with a bosch PAD pump and all LED bulbs. There just isn't enough output at low RPM. You have to basically assume that the max wattage is at like saturation at like higher RPM.

I basically had to run a crazy lithium ion cell so the pump wouldn't cut out at low RPM again at 55w. And it doesn't really charge till it is up at like 5000+ RPM.

Also swap everything to LED. It helps a ton.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

> Daniel '' Wrote:

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

> It’s just like Jeremy posted. You don’t need to float the ground on the

> hpi, only have to do that if you want to run ac and dc. To have the

> whole bike on dc all of your grounds need to be going to the black wire

> on the the rectifier, which to run dc needs to be hooked to the

> capacitor/battery (-) and not the earth ground.

Right, so with the headlight and pump on DC, I'll need to float the ground (not to frame ground) Right?

Re: Crazy Custom Frame Hobbit

Jeremy posted the diagram, just follow that and you’re good. Put both yellow off the rec to the one yellow stator wire and float the light and pump grounds to the (-) of the capacitor or battery. As others have said the output isn’t great on the mini rotor. I would grab a small agm battery, a 5ah would run your set up on a total loss for probably 3-4 hours.

Re: Crazy Custom Frame Hobbit

Tweaker trash /

> Daniel '' Wrote:

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

> Jeremy posted the diagram, just follow that and you’re good. Put both

> yellow off the rec to the one yellow stator wire and float the light and

> pump grounds to the (-) of the capacitor or battery. As others have said

> the output isn’t great on the mini rotor. I would grab a small agm

> battery, a 5ah would run your set up on a total loss for probably 3-4

> hours.

Yea i would run the water pump off the battery and use the hpi light coil for ur lights.

You can buy some pretty small lithium 5ah-9ah 12v from chine for dirt.

I like using electric power tool batteries, it makes charging headache free, and a lot of Etsy and eBay guys sell mounting plates and adapters for easy install and sleek look

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

yeahhh I might have to go with that but I'm hoping to avoid a battery if at all possible, so gonna try to float the ground first

Re: Crazy Custom Frame Hobbit

So HPI Mini is 55w MAX output.

You are into the same situation nearly every water cooled scooter I have ever had with a smaller than stock iggy has.

You simply can't run a decent water pump at full output + lights at idle or low RPM.

Issue 2 is you have nothing to smooth out the voltage pulses from the lighting coil. I would look into an Antigravity battery. They are the size of like 2 decks of playing cards. You can use a largeish capacitor that would be a bit smaller but that doesn't solve your lack of power issue, it will simply help with the voltage spikes at lower RPM that make your lights flicker, and if you don't have enough power anyway it won't matter.

You could re wire the iggy to output more watts, but it will always be choppy at idle.

You can float the ground all day but its pure work units your lacking.

You have 55w available at lets say for the sake of argument, 6000 RPM.

Thats about 4 and change amps @ 6000 RPM

Your pump is probably drawing 1-2 amps , plus whatever lights you are trying to power. if you have a 20w bulb your drawing another amp on top of that. At 1500RPM you would be lucky to be making 2amps of power. You can see the problem you will be facing here.

You need to put as low wattage bulbs as humanly possible, and either get a super low wattage pump or dish out for a pump that has temperature control (Malossi energy pump has an add on that will under volt the pump at x engine temp, $$$$) Or add a battery and charge it after every ride like every other watercooled scooter with an inner rotor or lightweight iggy has to.

Re: Crazy Custom Frame Hobbit

Totally normal JBOT /

Stock hobbit points to cdi conversion powers it all easily. Fuck hpi for this reason.

Red coil alone runs a Bosch water pump easily

Then the yellow runs a 55w halogen, and big rear led

Yeah I have a lil more rotating mass but it’s a trade off

Re: Crazy Custom Frame Hobbit

I should also note, that on my setup, it was on a derbi (doesnt matter), but I was running a bosch pump, 2 halogen headlights, and an led headlight. it made enough power to use all of the accessories, and the battery remained at 11 volts or so after multiple 3 hour rides. I was hesitant in adding a battery at first, but for peace of mind knowing all of your lights will work and engine wont overheat because your pump is always working, is well worth it.

Re: Crazy Custom Frame Hobbit

Sorry guys, I missed some stuff and tried to read the last page or so to get my feet on the ground as far as the current (pun) issue.

A bridge rectifier would glean more power out of this system right?

Assuming the pump is a DC motor (which it most certainly is)

I only sorta kinda understand this crap, but I think I am stating it correctly. We get 12V RMS from out coil. Rectified, it would produce higher DC output. Could charge a battery and accomplish more work.

Am I thinking crazy or does that make sense? I bought a couple of those 50amp bridge rectifiers to make my LED turn signals work and make smooth DC for a temp guage.

F25B9280-78C7-4BBB-9918-36C1C189810F.jpeg

Re: Crazy Custom Frame Hobbit

You'll get the -ve ac pulses with bridge rectification but I think the trail tech is already bridge.

Re: Crazy Custom Frame Hobbit

Wait hang on, how many lighting output wires does the hpi have and what model of trail tech reg do you have?.....

You may have an issue that may make it better but it won't be a magic fix. Your still gonna be down on power.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

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