Hawk is here, yay!

[Megadan]

Beauty shot.

[Megadan]

Finally got my IMS shifter installed. Borrowed the 8mm headed bolt from the EMGO unit I bought and I was able finagle it together.

The more inboard position of the peg is rather nice. A part of me wants to modify the brake pedal to give a little more room as well.

[Megadan]

In other news, since it really didn't cost me anything I went ahead and ordered a PWK 30mm flat slide carburetor with power jet. I also ordered a whole assortment of jets to go with it. Since I get "points" at work for things like perfect attendance and doing a "good job" that I can turn into things like Amazon gift cards, I went ahead and blew some of those points just for some fun experimentation.

From what I have seen, since the PWK doesn't have a flange mount, this style of intake should work with it. https://www.aliexpress.com/item/MIKU...308.0.0.BJUESk

The only catch is that I have to figure out how to do the intake side of things. Since the PWK carb has a 50mm inlet flange diameter, the stock intake tube is definitely not going to work with it. For now I may look into an angled Uni pod filter, but I would like to modify and utilize the stock airbox in some way.

The real question is... Should this be a part of my "modified" dyno run? Or should I stick to the PZ30/VM26 style carb. I honestly doubt there would be a huge difference in power between them with the stock cylinder head ports still in play.

[Weldangrind]

This is my favourite pod: http://www.ebay.com/itm/BLACK-42mm-4...FZNmYc&vxp=mtr


There might be some difference between the carbs, since the butterfly choke on the Mikuni could cause some turbulence. Who knows? If you have use of a dyno, why not quantify the changes?

[Megadan]

Originally Posted by Weldangrind

This is my favourite pod: http://www.ebay.com/itm/BLACK-42mm-4...FZNmYc&vxp=mtr


There might be some difference between the carbs, since the butterfly choke on the Mikuni could cause some turbulence. Who knows? If you have use of a dyno, why not quantify the changes?

That filter would be great, but finding a pod filter with much of an angle on it with a 50 or 51mm ID seems to be a challenge. I may have to make an intake tube, but I want to hold off on ordering parts until I know what kind of potential differences I will be dealing with. One big unknown is if the angle of the carburetor itself will be different with that carb boot I linked.

What I would like to do is mount/epoxy a short length of pipe that sticks out on both ends where a filter can be mounted inside the airbox, and I can also have a separate intake tube.

If all else fails, I will just use a short length of bent mandrel tubing and do the trash can mod to help protect the filter.

You are right about there being a potential difference. Without the butterfly for the choke in the air path, and a larger mouth and intake tube leading into the carburetor, there will be less turbulence and resistance. this style of carb may well be good for half a horsepower or so.

Funny note about the knock off PWK I ordered. It uses Keihin jets, but a Mikuni needle. Gotta love the Chinese lol

[Megadan]

Minor little upgrade of sorts. I never did like how low the spark plug wire sat on the bike. Heat from the cat was actually starting to deform the insulation. I decided to do something about it. With some parts I had laying around.

Enter the NGK XD05 plug cap, one of four I bought a couple of years ago for my goldwing. Much taller than the cap that comes on the Hawk, it was just what I was looking for.

The only catch was, it is a resistor cap. So I replaced the resistor with a twisted up plug of copper wire I made stripping back some leftover 16ga I had laying around. Works like a charm, and the wire is waaay far away from the exhaust now, It also let me remove the retainer clip from the carb flange. Removed almost 6 inches of plug wire, and it really cleaned up the look of the bike too.

[Megadan]

How it looks on the bike. You will also note a lack of my heat reflective foil. It started to come off the bowl so I removed it. I tried to get by with a simple wipe down, but I must not have got it clean enough. I will try again here soon. I have a ton of the stuff anyway lol.

[Megadan]

Going in today to my least favorite place on earth, the DMV. Time to register and title this guy so I can legally ride. Expect a lot of miles to rack up on this girl now lol.

[ben2go]

Nice job on the plug cap. It should be good for a long time.

I've never heard anyone say they enjoyed going to the DMV.

[Megadan]

Originally Posted by ben2go

Nice job on the plug cap. It should be good for a long time.

I've never heard anyone say they enjoyed going to the DMV.

It actually wasnt too bad this time around. Only a few people there. In and out in less than 20 minutes and she is legal now.

[hertz9753]

The day I went to get my title and registration Donald Trump was in Bismarck to give a speech in 2016. I walked in and saw lees than 10 people. Nobody was arguing about gross weight and net weight and why it increases the registration fee.

I have never understood why some people would use the chair to sit down and challenge something that they know is true with a DMV worker that can't haggle on price and waste other peoples time...

[pete]

Originally Posted by Megadan

In other news, since it really didn't cost me anything I went ahead and ordered a PWK 30mm flat slide carburetor with power jet. I also ordered a whole assortment of jets to go with it. Since I get "points" at work for things like perfect attendance and doing a "good job" that I can turn into things like Amazon gift cards, I went ahead and blew some of those points just for some fun experimentation.

From what I have seen, since the PWK doesn't have a flange mount, this style of intake should work with it. https://www.aliexpress.com/item/MIKU...308.0.0.BJUESk

The only catch is that I have to figure out how to do the intake side of things. Since the PWK carb has a 50mm inlet flange diameter, the stock intake tube is definitely not going to work with it. For now I may look into an angled Uni pod filter, but I would like to modify and utilize the stock airbox in some way.

The real question is... Should this be a part of my "modified" dyno run? Or should I stick to the PZ30/VM26 style carb. I honestly doubt there would be a huge difference in power between them with the stock cylinder head ports still in play.

I have them on 2 of my bikes....
77 Montesa Cota 348 has a 26mm OKO
TTR250 has a 32mm Koso "chinese copy of the OKO"

good carbs... the 32 on the TTR was a bit finiky to get the jetting right
I found the easyest way was to plug the power jet tube while getting the
jets right.. then reconnect it then you were pretty close with the jets..
I prob had it right 10 times... but yer always think one bigger or smaller
move the needle... will be better....maybe I just don't know when to stop fiddling...

The one on the Montesa came pre-jetted from Sammy Millers classic trials in the UK
so that one was easy... plug & play...



..

[Megadan]

Originally Posted by pete

I have them on 2 of my bikes....
77 Montesa Cota 348 has a 26mm OKO
TTR250 has a 32mm Koso "chinese copy of the OKO"

good carbs... the 32 on the TTR was a bit finiky to get the jetting right
I found the easyest way was to plug the power jet tube while getting the
jets right.. then reconnect it then you were pretty close with the jets..
I prob had it right 10 times... but yer always think one bigger or smaller
move the needle... will be better....maybe I just don't know when to stop fiddling...

The one on the Montesa came pre-jetted from Sammy Millers classic trials in the UK
so that one was easy... plug & play...



..

Thanks for the advice with the power jet, that's a good idea to eliminate that variable. Honestly, my biggest hurdle is to figure out is what jets to start with. I can always go on the "definitely too rich" side, Thankfully the pilot circuit should be the easy one. A 40 is going to be close lol.

[pete]

The standard main in the TTR was a #148 30mm carb
with the 32mm Koso I'm running a #157..
not sure.. think it's got a #42 pilot .. standard was #40
needle... centre groove ?

but it's a bit lean on the pilot as it's rich on the main...
but the power jet takes care of that when you snap the
throttle open at low revs...

what I have found over the years to get the pilot right/close
if you can start a cold motor with out choke you are to
rich "big" on the pilot jet...

my bike is a dirt only so it not running at constant revs for
long periods " or even short periods "
so my jetting requirements will be a bit diffrent...



..

[Megadan]

Your method for determining pilot size is close to mine. I have always aimed to have a bike that will just barely try to start cold with no choke. That usually indicates to me that the idle mixture is set fairly close. From the size ranges you are describing, and the obvious differences in displacement power, and airflow between the TTR250 and the CG250 engines, I think a 40 pilot is a perfect starting point. Main jet, with all mods, minus the head work, I think a safe starting point would be a 140 would be a safe (likely rich) starting point.

I just got the carb in today. I must say, for the money, this is a rather well built carburetor. The idle mixture screw is an air metering type and the screw is on the left side as well as the idle speed screw, which is both thumb turn or flathead. The only thing in kind of an awkward place is the choke pull, which is also on the left side but is rather high up. It might be awkward to get to installed on the bike, so I may look into doing a simple choke cable setup for it.

Honestly, the only thing kind of less than spectacular with the quality is just the finish on it, which is just a bit discolored and dirty looking. Nothing a little time with some steel wool and WD40 couldn't fix. That said, the bore machining is beautiful. While I wait for my laundry I am going to take the carb apart and clean it really well and try to shine it up a bit.

Went ahead and ordered an intake for it as well as an angled Uni filter for now. I will try to sort out a better air filter/intake solution in the future, but this will get it up and running. I don't plan on crossing any bodies of water any time soon, so the pod filter will be fine. Likely I am going to find a piece of 2 inch aluminum mandrel tubing that will relocate the pod to where the airbox used to be, or mod the airbox so that the pod sits inside of it. I will cross that bridge when I get to it though.

I will say this, and I agree with Pete and his many assertions in other threads, the PWK/OKO/KOSO flat side carbs are going to definitely offer a performance increase over the VM26/PZ30. The lack of reduction down to 26mm like you find in the VM26 is going to make a big difference in airflow. The real question is, how much of a difference will it make.