Puch head on hobbit, pics and warning.

What you gotta do.

Slot the holes, space the bolts, or you'll snap em off

Bingo.

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Re: Puch head on hobbit, pics and warning.

Or just use puch studs like I did.

Re: Puch head on hobbit, pics and warning.

Yep. I did two in just like that....however.....I was OK with 4 new bolts and no spacers, but I like Dat #jbotbrohobbitmaster

Re: Puch head on hobbit, pics and warning.

I use a mill bit in a drill press to slot the openings and use puch studs with a spacer alot like your pics. Best ac setups on hobbits imo. Temps seem to stay sub 400 even with heavy blasting on a dr kit

Re: Puch head on hobbit, pics and warning.

JBOT, what did you use to slot the holes? Also did you use he hobbit head gasket or a Puch one?

And lastly, what temp difference did ya notice? Thnx

Re: Puch head on hobbit, pics and warning.

Dremel

I never use headgaskets if possible.

Just a thin film of yamabond

Temps easily 100deg down with eurokit head

Re: Puch head on hobbit, pics and warning.

Dirty30 Dillon /

I picked up a derbi head I"m going to use for this. Plug the decomp, my hobbit is KS.

Only reason I don't plan on using one of the numerous Magnum head I have is because I have tall rear shocks, and to get the head to clear the stock tank/petcock I'd be chopping away most of the upper fins anyways.

Re: Puch head on hobbit, pics and warning.

I did this with an a35 head A+ would recommend.

Re: Puch head on hobbit, pics and warning.

Hydra,

Might as well use a nice chamber without decomp.

Why swap to another poorly designed chamber?

Makes no sense

Re: Puch head on hobbit, pics and warning.

Dirty30 Dillon /

JBOT, a friend Wrote:

-------------------------------------------------------

> Hydra,

> Might as well use a nice chamber without decomp.

> Why swap to another poorly designed chamber?

> Makes no sense

Really, head exterior dimensions were a main factor. I don't have a problem filling the decomp and stuff and cutting a squish. The derbi head and the magnum heads are free, so I don't mind cutting/hacking.

Re: Puch head on hobbit, pics and warning.

JBOT, a friend Wrote:

-------------------------------------------------------

> Hydra,

> Might as well use a nice chamber without decomp.

> Why swap to another poorly designed chamber?

> Makes no sense

yeah the airsal 47mm head is pretty bad. The older legit metra heads are much better. I use a stock decompless derbi head cut to mimic a gila squish and chamber on my fast-ish derbi. Makes a surprising difference in cooling and power.

Re: Puch head on hobbit, pics and warning.

Pic comparison. WoW what a difference! Got it today in the mail.

The biggest pain is spacing the bolts. I tried eyeing it and stripped one of the holes. Best thing to do is stick the bolt through the stock head and cylinder and measure the bolt threads sticking out and repeat with the airsal head and measure the difference. Waiting till tomorrow for the locktite to dry on the helicoil before attempting to torque the head down.

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Re: Puch head on hobbit, pics and warning.

You just didn't go far enough on the diagonal.

You can't go too far, so if in doubt, go farther

Re: Puch head on hobbit, pics and warning.

JBOT, a friend Wrote:

-------------------------------------------------------

> You just didn't go far enough on the diagonal.

> You can't go too far, so if in doubt, go farther

lol, good eye. Scared to go past gasket surface area.

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Re: Puch head on hobbit, pics and warning.

Why? There's nothing to seal out there.

I'd go further. Look at my pic!

Re: Puch head on hobbit, pics and warning.

Btw, what head is that?

The combustion chamber looks very odd past the squish

The bottom left hole is not diagonal to the plug hole.

You should fix thisEdited 1 time(s). Last edit at 10/29/16 12:43AM by capturedbyrobots.

Re: Puch head on hobbit, pics and warning.

Yea, the bottom left hole went a bit to the side and not straight down'ish/diagonal. I'll clean it up a bit.

This is the head I got. Got the last one it seems.

https://www.treatland.tv/ProductDetails.asp?ProductCode=puch-airsal-47-head-04030247

Re: Puch head on hobbit, pics and warning.

The good and the bad:

* Looks kick-ass

* Use of honda-bond no bueno in the head (I used it in-between the gasket) developed leak. Torqued at 7Ibs.

Plus, I think it would create a barrier between the contact surfaces..i.e heat sink affect ( at least my theory)

Going to let the bike cool and clean everything up and seal the head with just the gasket.

Will report back results etc...........

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Edited 1 time(s). Last edit at 10/29/16 01:28PM by kabooski.

Re: Puch head on hobbit, pics and warning.

Youre mistaken.

I use yamabond between head and cyl on everything.

It hurts nothing.

Something else is wrong

Did you plug your decomp in case it isn't covered?

Re: Puch head on hobbit, pics and warning.

Btw, generally you need no head gasket on hobbits.

On a DR, with no base gasket and no head gasket the squish is usually at 1mm. You just add to that with a base and head gasket which makes your tuning more shitty

Re: Puch head on hobbit, pics and warning.

hmmm, yea, I had the gasket with the hole in position. I've switched it to cover the hole. I'm using copper spray on the head with the gasket. Read this after I already had everything mounted. Now I've misplaced one of the bolts lol

be back laterz

Re: Puch head on hobbit, pics and warning.

I've just made the same mistake and bought the same head thinking it'll be the same as yours jbot! Yours was the 47mm eurokit head and the 46mm head which I've bought seems to have no squish band.

I'm not too sure if I want to use this now paired with a polini kit.

Think I should just try this?

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> JBOT, NOT YOUR FREN AT ALL Wrote:

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

> Btw, what head is that?

>

> The combustion chamber looks very odd past the squish

>

> The bottom left hole is not diagonal to the plug hole.

>

> You should fix this

Re: Puch head on hobbit, pics and warning.

yeah that head in the top picture SUCKS

the 'squish band' has a huge angle and is not a squish band at all, the chamber is too small and not enough spark plug threads to even re-cut it. they don't have long-reach plugs so if you do try to cut them deeper you run out of plug threads which is no bueno.

Re: Puch head on hobbit, pics and warning.

Yeah, the top pic head isn't very good. Combustion is tiny.

Squish isn't great but it is there.

You don't need too much.

Might not be primo-optimal it will do the job.

I'd throw it on the lathe and just open up the chamber.

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