OzVMX Forum

Marque Remarks => Yamaha => Topic started by: Graeme M on April 12, 2011, 10:39:27 pm

Title: Power jet IT175G - where's it go?
Post by: Graeme M on April 12, 2011, 10:39:27 pm

OK, I gotta ask. Where does the hose from the power jet on the carby go? I've been told to the carb overflow, but every photo I see seems to show the overflow hose, well, overflowing under the bike and the powerjet hose going to the front of the carb. But on my carb there is no sign of any spigot it could go to OTHER than the overflow. So what are the facts?

Title: Re: Power jet IT175G - where's it go?
Post by: Lozza on April 12, 2011, 11:07:24 pm

Facts  ???(this is Ozvmx)  Depends if you have a add on or OEM power jet, the add on you remove the brass overflow tube and attach 1 end on the hose onto the over flow outlet and the other onto the power jet housing. The OEM power jet could have a boss in the float bowl drilled out to draw the fuel from.

Title: Re: Power jet IT175G - where's it go?
Post by: mboddy on April 13, 2011, 07:10:50 am

A non-powerjet Mikuni carby has a brass overflow tube inside the float bowl that connects to the overflow hose.
On the powerjet Mikuni this tube is missing and the spiggot for the overflow hose is used to connect the powerjet hose. 

Title: Re: Power jet IT175G - where's it go?
Post by: RED ALERT on April 13, 2011, 07:34:34 am

Just wondering what classes can legally run the add-on power jet kits?
I thought probably not pre75, but maybe pre85?

Title: Re: Power jet IT175G - where's it go?
Post by: mboddy on April 13, 2011, 07:40:47 am

Mikuni powerjet came out on 1979 Yamaha TZ350F and 1980 IT175G.

Title: Re: Power jet IT175G - where's it go?
Post by: Lozza on April 13, 2011, 08:20:15 am

Doc posted a pic from a Mikuni power jet carb from a snow mobile that was very early 70's.

Title: Re: Power jet IT175G - where's it go?
Post by: mboddy on April 13, 2011, 08:58:47 am

Quote from: Lozza on April 13, 2011, 08:20:15 am

Doc posted a pic from a Mikuni power jet carb from a snow mobile that was very early 70's.

I would be very interested in that.

Title: Re: Power jet IT175G - where's it go?
Post by: Lozza on April 13, 2011, 10:17:21 am

Search function ;)  ;D (and the Suzuki section where all the knowledge is ;D )

http://ozvmx.com/community/index.php?topic=17530.0


http://ozvmx.com/community/index.php?topic=1642.0


http://ozvmx.com/community/index.php?topic=11441.0

Title: Re: Power jet IT175G - where's it go?
Post by: Graeme M on April 13, 2011, 10:25:17 pm

Thanks for the replies on this one. I am still confused though, but perhaps I will just not think about it. I have connected the powerjet to the 'overflow' spigot and that's how it's been since I rebuilt the bike. It runs just fine. But why does every photo show something different? Here's an example, tho it's a US spec bike. maybe that's the difference? Anyway, you can see the overflow is at the bottom beneath the air intake bell. But the powerjet hose sneaks off round the front. As it does in every photo of an IT175 I can find on the net. What gives??
(http://i626.photobucket.com/albums/tt346/wrxmark/Yamaha%20IT175/MotorcyclistMay1980IT175page7.jpg)

Title: Re: Power jet IT175G - where's it go?
Post by: Lozza on April 13, 2011, 11:32:05 pm

 They looked to tucked it round the front just for the photo. I have a few here and installed the Mikuni PJ kit and it says to remove the brass overflow tube inside the bowl and use the overflow outlet.

Title: Re: Power jet IT175G - where's it go?
Post by: bazza on April 18, 2011, 09:04:47 pm

thinki have one in box of mikuni parts could check and take photo?

Title: Re: Power jet IT175G - where's it go?
Post by: Graeme M on April 18, 2011, 09:14:35 pm

Go for it Bazza. I'm just curious now, it seems the overflow spigot is where it goes but it's weird that the parts diagram and any photos I've seen show something different...

Title: Re: Power jet IT175G - where's it go?
Post by: frostype400 on April 18, 2011, 09:19:45 pm

Here is my 38mm mikuni got the power jet with all the instructions still have the instructions somewhere I think.

(http://i656.photobucket.com/albums/uu283/frostype400/DSCN0210.jpg)

(http://i656.photobucket.com/albums/uu283/frostype400/DSCN0209.jpg)

It goes to the overflow I remember pulling the brass overflow tube out. :)

Title: Re: Power jet IT175G - where's it go?
Post by: bazza on April 19, 2011, 03:06:05 pm

found my round slide power jet Mikuni but had used bottm bowl on somwthing else over the years

Title: Re: Power jet IT175G - where's it go?
Post by: Dino Rider on May 08, 2011, 09:31:11 pm

Just had a look on mineand the carby bowl has two spigots, one out the back for overflow and one out the front for the power valve.

Title: Re: Power jet IT175G - where's it go?
Post by: Graeme M on May 09, 2011, 06:05:10 am

Thanks, that's exactly how it looks in all the pics.  Mine definitely doesn't have the front spigot...

Title: Re: Power jet IT175G - where's it go?
Post by: bazza on May 09, 2011, 08:17:54 am

had forgotten about this and looking at mikuni sights saw a photo of carb with powervalve will try to find it for you. check photos at www.gixxer.com

Title: Re: Power jet IT175G - where's it go?
Post by: Kev on December 28, 2013, 06:34:40 pm

I've just fitted a mikuni OEM's power jet to a VM34, no drama fitting it as it uses the overflow spigot and the overflow tube is removed. All as per instructions. My question is that now I don't have an overflow circuit so what's going to happen if my float valve sticks open? Fill my crank with fuel I guess. Is there something missing from the instructions ? Should I add a spigot for overflow?