Brozz 250 Head Porting

[tknj99]

Originally Posted by JerryHawk250

Use regular motorcycle oil and lubricate the rockers and valve stems.

Thanks Jerry, i assume thats a no on the blue locktite question.. will just use the Rotella and finger oil all of the bolts and drizzle some onto the valves

[tknj99]

So i should receive the head and timing key in the mail today (finally) and look forward to installing the head. I will take pics and then write up a review on the head porting gains from Joe H.
I also have the flywheel puller being shipped and i bought an air impact wrench. I have no doubt that it will be easy to remove the flywheel bolt and the puller should make it easy as well for its removal, but wanted to find out, does anyone know what the torque spec would be for the flywheel bolt when i go to reassemble it? Or should i just use the impact wrench until it seats well? thanks

[tknj99]

Update: received the ported head back earlier today. Added some pics to this thread of the work performed by Joe at Henner Motorsports. He did the intake and exhaust porting and polish work. All of the help received in this thread was great and i torqued the bolts as specified.. it was a bit tricky getting those rods seated but finally got them lined up and put everything all back together.

Impression: i took the bike for a good 20 mile ride and can definitely feel the increase in power from 4500 or so rpm up to redline. It has a nice pull now, especially noticed when going uphill in 5th i would sometimes need to downshift as it would start slowing down, but now i can stay in 5th and accelerate out of it. All in all im very happy with the results. Not sure if it winded up as a 4hp increase or not, but definitely feels good.. before i would worry on merges and keeping up with cars but not anymore.

Next stop: install the 4 degree timing key.. curious what improvement that will yield.

[Megadan]

With proper jetting a ported head should see at least a 2 to 3 hp increase at the rear wheel depending on the carb you have. The 4 degrees of extra advance will also make a nice subtle improvement across the board.

[tknj99]

Originally Posted by Megadan

With proper jetting a ported head should see at least a 2 to 3 hp increase at the rear wheel depending on the carb you have. The 4 degrees of extra advance will also make a nice subtle improvement across the board.

Thanks.. right now i upped it from the 115 main to 120 main but still kept the 2 washers under the needle jet. Maybe ill try adding a 3rd washer to see if it makes any difference in a good way.

[China Rider 27]

Nice pix! I noticed the same thing after porting, the motor sustains speed up hills much better and has more power on demand within the productive rpm range.

[JerryHawk250]

Porting the heads on the little engines has to be one of the best mods. The 4 degree timing key is the icing on the cake. Got my two timing keys yesterday. Looks like i'll be working on the Ghost and Hawk over the weekend.

[tknj99]

Originally Posted by JerryHawk250

Porting the heads on the little engines has to be one of the best mods. The 4 degree timing key is the icing on the cake. Got my two timing keys yesterday. Looks like i'll be working on the Ghost and Hawk over the weekend.

Nice! Are you planning on a video of the process on the Hawk?

[JerryHawk250]

Originally Posted by tknj99

Nice! Are you planning on a video of the process on the Hawk?

I sure will.

[tknj99]

Originally Posted by JerryHawk250

I sure will.

Sweet! By the way, i found out the torque spec for the flywheel bolt is 54 ft/lb

[JerryHawk250]

Originally Posted by tknj99

Sweet! By the way, i found out the torque spec for the flywheel bolt is 54 ft/lb

I think I might have mentioned that in my video on the X22R.

[tknj99]

Originally Posted by tknj99

Thanks.. right now i upped it from the 115 main to 120 main but still kept the 2 washers under the needle jet. Maybe ill try adding a 3rd washer to see if it makes any difference in a good way.

I think the 3rd washer pushed it into too rich territory, ran fine but noticed some slight backfiring on deceleration and also the plug was fairly black and sooty. I stepped it back to 2 washers on the needle jet. I think the 120 main is fine for now, dont think it needs to backed down to a 115 just yet.

[Megadan]

Originally Posted by tknj99

Sweet! By the way, i found out the torque spec for the flywheel bolt is 54 ft/lb

That's about 5 uga-duggas.

[Deckard_Cain]

Originally Posted by tknj99

I think the 3rd washer pushed it into too rich territory, ran fine but noticed some slight backfiring on deceleration and also the plug was fairly black and sooty. I stepped it back to 2 washers on the needle jet. I think the 120 main is fine for now, dont think it needs to backed down to a 115 just yet.

I'm running a 120 main at 600ft with a henner port job on my hawk head, full exhaust, intake, tiing advance key, et AL ... everything but a cam.

I found it was perfect until the air temp dropped below 40degrees.

[tknj99]

Originally Posted by Deckard_Cain

I'm running a 120 main at 600ft with a henner port job on my hawk head, full exhaust, intake, tiing advance key, et AL ... everything but a cam.

I found it was perfect until the air temp dropped below 40degrees.

Thanks for that info, your at my same elevation with similar mods, are you running the stock carb? if so, any washers under the needle jet?
if not stock carb, have you moved the clip down on the needle jet? thanks
I haven't changed out my pilot jet for reference