350x Head Porting?

[jaykup]

I have seen a few posts on people doing this, where can I get it done? I have seen prices from 50 dollars to 125-175 to 400 some dollars.

What are a few places that do this or even specialize in 350x heads?

[Billy Golightly]

Mickey Dunlaps Four Stroke Tech I think will still work on 350Xs. Someone told me a while back they talked to Curtis Sparks and he would too, just doesnt mess with 200x parts anymore. And then theres Tom Carlson of TC Racing. All three of those guys are oldschool trike gurus that were doing work when the 350Xs were brand new. Can't go wrong with either of the 3 IMO.

[Yamahondaman]

iv'e done a couple of 400ex heads along with a Triumph,Hyabusa,Kawi 1000,etc ..... just make sure who ever does the job doesn't mess it up !!!

[jaykup]

Would you be willing to do my 350x head? I always wanted to get into porting myself, once you understand it, it doesn't seem hard. Is there a good book or some other way to learn this?

[Mobular]

Any bike shop that does custom engine work will do it. Just don't overdo it. A little goes a long way!

[jaykup]

I just got off the phone with Tom Carlson (very helpful) and Curtis Sparks (doesnt do 350x anymore).

My end goal here is to have a Powroll 430 BB kit with all the goodies.

Tom told me I needed to do a few things in order.

-First is to build up the motor with a cam that matches it, correct piston, connecting rod, etc.
-Second is to get a proper exhaust for it. I suggested the DG or Cobra exhaust systems since that is all that seems to be available for this trike, and he told me those systems are garbage. They are stock replacements that are just an added silencer can with some tubing going from the motor to the can. Real racing exhaust systems are custom made, correct lengths, and may be significantly shorter than OEM.
-Third is to work on a new carburator, I suggested a 39mm Keihin FCR carb and he said that would be ideal for this setup.
-LAST is going to be your porting. The porting is what is going to compliment the mods you already have and be designed to help with the current riding you want to do (trail riding, sand riding, etc.) I chose trail riding and he said you want to focus on getting gobs of torque at quarter to half throttle. I told him some of the trails are flat stretches that can last for 2-3 miles and I would like to be able to really open it up and fly through those, would that be ok with all that "gobs of torque?" Definitely, he replied.

He told me a matched porting system like that would cost me around $500 dollars to do the head.

He also stated that you need to replace the CDI with a CDI box. The stock one is good to rev to about 8K, but after that it starts to retard the timing and you lose a lot of power. He still makes one that would correct this problem. I didnt get a price on this however.

It seems like 500 dollars is a little high, but he has gotten various awards including the Engine Builders award.

This will be good info for anyone else thinking about doing the 430 kit.

[TtownJoeShow]

i have seen a thread on porting, it was called "what to cut" or something like that...i searched but came up with nothing

[Yamahondaman]

CUT IT OUT !!!!! Polish the Exhaust and Bead Blast the Intake "after Porting"...
HOG IT !!!! TORQUE is what you Want !!! BIG Jetting !!

[phil53]

Definitely need a bigger carb, or else you won't be able to kick it over.
You will also have to remove the air box lid or the whole airbox, the 350x airbox is small and can't handle the cfm of the big carb and bore.

Let a pro do it, you get what you pay for. I paid $150 for my port job on the 350x, it's good, but, I am only running a slight overbore with a 10:1 compression and a midrange cam.

Will need valve springs also. hardened rockers. will have to shim the springs also. hows the cam bearing journals on your head?

[Yamahondaman]

i'll tell you what .............. send it to me ..................
i'll port it...you ride it "with the stock carb." and we or ....... "they" will see who's the Pro !! PM ME............... 2 WEEK Turn Around .........

[jaykup]

Definitely need a bigger carb, or else you won't be able to kick it over.
You will also have to remove the air box lid or the whole airbox, the 350x airbox is small and can't handle the cfm of the big carb and bore.

Let a pro do it, you get what you pay for. I paid $150 for my port job on the 350x, it's good, but, I am only running a slight overbore with a 10:1 compression and a midrange cam.

Will need valve springs also. hardened rockers. will have to shim the springs also. hows the cam bearing journals on your head?

If you read my sig it says I have already removed the air box lid. The Powroll kit that I want comes with better valve springs, and hard face rockers are a must. I'm sure my cam journals are worn from normal use, but probably still with in speck (which will be checked before I install a cam).

Where did you go to get a port job done for 150 dollars?

[jaykup]

i'll tell you what .............. send it to me ..................
i'll port it...you ride it "with the stock carb." and we or ....... "they" will see who's the Pro !! PM ME............... 2 WEEK Turn Around .........

I may take you up on this offer, and I'm sure it will work with the stock carb, but I really want something larger (39mm at least) to complement the 430 kit with a high lift/duration cam.

Jake

[NOS_350X]

Tell me where you want the power and send it to me. Ive done a bunch of them and ask anyone thats seen my X go, SHES A RUNNER.

[Yamahondaman]

I'll do the Fly Wheel and NOS can do the Head !!! it'll RUN !!! :w00t:

[jaykup]

Tell me where you want the power and send it to me. Ive done a bunch of them and ask anyone thats seen my X go, SHES A RUNNER.

Sure, I would like it for trail riding, I think a port job going for midrange to high power would be great. The cam I want is .360 Lift and 284 Duration, its the Web Cam just below the Race One. I think the stroker kit will give me plenty of low end torque I desire, and this port job will match the cam nicely. Think it will be ok?


I'll do the Fly Wheel and NOS can do the Head !!! it'll RUN !!!

Do you mean lighten the flywheel? How will that run in the trails? Won't I loose almost all of my torque?

[NOS_350X]

I have the lightened flywheel on my X (done by yamahondaman) and you dont loose any torque, you have a faster revving engine and instant thorttle response. But no loss in torque or problems with stalling the engine.

also what exhaust and carb are you running?

[jaykup]

I will run a 39mm Keihin FCR carb with a pumper on it (probably from a 400ex) and hopefully a custom exhaust, but probably a DG or Cobra.

[rot box]

I saw a 350X at the St. Anthony dunes (close to home :beer ) It looked stock, but man when you got close!

It hauled! It would walk on my 84 CR (which is no slouch), and he did all his own port work. From what I saw he had everything done that you have planned except for his one-off custom exhaust, and an 8" over swing arm. That bike really stood out (something about old honda's wailing on new bikes makes me happy :naughty: )

Point of this long story??? If you play your cards right, and keep it cool I think you'll be quite happy....Keep us posted!

[phil53]

a local shop ported my head, he's been around and raced atcs when they were new. I wasn't building a monster racer or anything so it fit my needs.

I wasn't putting anybody's personal port work down, I wouldn't port my first head on something that parts are becoming hard to find.

[Erics350x]

have you thought about have an Extrude Hone done instead?

[Yamahondaman]

what most people do when they first start out is to Port there own stuff .... get a Dremmel or die grinder and start HOGGING ..........