My 350X needs ..UMPH Gearing?,head work? Jets? HELP

[Tyler 54]

So far, I have a Wiseco 10.25:1 compression .50 over Wiseco piston. A small unknown cam, a full DG Exhaust, and a UNI filter. I am running 13 /42 gearing, and 20 inch RAZR's.

I'm happy with it, but it stil wont beat a 400EX :WTF: Is it in my gearing?? or maybe I need to Rejet? I'm tjinkign of trying some of the following :

I'd like to see about getting the head ported and polished.I know this has been asked before, but how much am I looking at for a good port/polish job? And how much performance gain will i get?

I also have been looking into a web cam. I have the hard weld rockers. Has anybody on here had any luck with a slightly bigger cam?

The reason I took it apart is because it dropped a valve. Were can I get oversized valves? or Titanium valve springs?

I was told stock 350X has a 138 or 140 main jet in it. With my piston, exhaust, and light cam, Can anybody tell me what a Good Jet size to start at when i re jet? I was thinking 148, but who knows? Also what is the slow jet? Will I need to change it to? I really have no clue how to jet

thanks for the help guys:D

[whiteman350x]

You can get the ti valve springs from webcams. They also come w/ the retainers(I think).

Whiteman

[3WheelsForever]

Yikes! 42 rear tooth? You prolly get them off the line dont you? Id go with a 14 up front and a 38 in back. Im running a 14 up front and that makes a good difference. The bottom is still great. The 38 rear should gain you a crapload compared to 42. You should still have good bottom end. I think youll like 14/38 better, especially with those mods.

[250sx]

I have a brand new webcam for a 350x I'll sell ya.

you're leaving out some info here. are you having trouble off the line beating them, on the big end, or are you just getting whooped the whole way through? :cool:

If you're killing them off the line & they come on around you then I'd say it was the gearing. If they're smoking you off the line too then, considering the sprockets you're running, you have other issues.

are you able to give it full throttle & keep the nose down when you launch? are you spinning or hooking the tires? what tires are you using & what kind of terrain do you race on? all of these are factors.

[Tyler 54]

Well Dan, I am racing on Dirt/pavement I had the 20 inch Razr's on it. In the dirt I raced a stock 400EX, and it was pretty even.... and no, I couldnt keep the front end down, I think I was wheelied up to 3rd gear. :headbang: He bette me by about a qaud length.

When I raced on pavement, I raced an almosy new 400EX that was piped (R4 WB) and jetted. It smoked me. Possibly because I couldnt get full throttle cuz it grabbed to much??? But yea, it smoked me all around. :wtf: ?

I do not have the DG head pipe on yet, and I have the 148 jet, it is not on either.

Dan, What you want for the WEB CAM :D I need it, and a T-3 flywheel.

Are you interested in soem BRAND NEW Honda 250R rear shocks? :thumbsup:

I got two up for trade, lol I alos started work today! let me know,

[Troll]

With that gearing and tire combo, the trike should crawl great in rough terrain.
For drag racing just start in second gear and dont over-rev before shifts.
At least that makes a huge difference with our 350X's.................:thumbsup:

[dividebyzero]

This is what i know:1.stock main jet-138.2.i have the second biggest cam(webcam)-yes it does make a difference(mid-topend-sounds awesome idling!)3.porting/polish makes a big difference-i payed $175 at my shop.4.The slow jet is the pilot jet-stock-40(85).5.The x doesn't have a rev limiter,so with your gearing and tires,over time revving it to the sky will blow your motor,rod,etc.With those tires you will want to run at least a 14 in front,36 rear.6.When i went with the 452 motor,it only needed to be jetted(main jet)up to a 140,and the pilot a whopping 65 to keep it idling!The problem is the carb is too small(took care of that)if it idled more than 10 sec it would foul a plug,but i don't see that happening in your case.I wouldn't think you would have to change the pilot jet for what you have(maybe 1 or 2 sizes).I have the full dg exhaust also with a k&n filter and outerwear.I'm not sure where you can get oversized valves,but,i wouldn't think you would need them.You can get the head shaved(more compression),flowed,3 angle valve job.Hope this helps.

[Black Sheep]

Originally posted by ReDnEcK KiD
So far, I have a Wiseco 10.25:1 compression .50 over Wiseco piston. A small unknown cam, a full DG Exhaust, and a UNI filter. I am running 13 /42 gearing, and 20 inch RAZR's.

I'm happy with it, but it stil wont beat a 400EX :WTF: Is it in my gearing?? or maybe I need to Rejet? I'm tjinkign of trying some of the following :

I'd like to see about getting the head ported and polished.I know this has been asked before, but how much am I looking at for a good port/polish job? And how much performance gain will i get?

I also have been looking into a web cam. I have the hard weld rockers. Has anybody on here had any luck with a slightly bigger cam?

The reason I took it apart is because it dropped a valve. Were can I get oversized valves? or Titanium valve springs?

I was told stock 350X has a 138 or 140 main jet in it. With my piston, exhaust, and light cam, Can anybody tell me what a Good Jet size to start at when i re jet? I was thinking 148, but who knows? Also what is the slow jet? Will I need to change it to? I really have no clue how to jet

thanks for the help guys:D


1. YES it is in your gearing. first you went up 2 teeth in the rear which adds tourqe but decreases speed. second you decreased tires size 2" and that also decreases speed but increases acceleration.

for 20" tires on a 350X you have to go down to a 38 sprocket just to get it back to the same speed as as stock set up 13/40 with 22" tires.

or with a 42 rear sprocket you could try 25" tires to achieve to same ratio's but 25" tires on a 350X are ill advised.

2. a "GOOD" port job cost between 250.00-350.00. the most critical thing to consider is if the place doing the porting has a flow bench. if a flow bench is not used a proper job can not be done. porting is the last step in a performace gain. it lets everything work at its peak level and is specificatly ported to the type of power you desire ( low, mid, top, ect.)

3. Web Cams are "cheap" rewelds. another words "globs" of metal welded on a stock cam. Megacycle ( ask your Honda dealer )
make all new billit cams that are a LOT stronger and last 10 times longer and they are only 30.00 more PLUS you get to keep your stock cam. with web you must send your stock cam in or pay a 100.00 core charge ( add that to the cost 90.00? ) your paying 190.00 for one reweld OR pay 130.00 for a billet cam and still have stock. HMMMMMMMMM

4. oversized valves do not work good with 350X's they have been tried but have shown to not offer any real benefits. Titanium can you say about BIG $$$$$$$$$ for not significant gain. yes they may be lighter and alow quicker revs HOWEVER the 350X does need to rev any faster then it does now. it is high strung stock.

5. stock is 138 main. 42 pilot/ slow jet
with your mods i would use as a BASE starting point a 150.

HOWEVER with the mods you have the next logical step ( before porting and valves ) is a larger carb. one of the best choices for your motor would be a keihin 36mm round slide ( PD?) unless you can aford a keihin FCR

[Tyler 54]

hey guys, thank you for the help. I looked at my sprocket again ..and I was wrong it's a stock 40 tooth.

Bigger carb ehh? Wahts the difference on price on the carbs, and how much different are they as far as performance.

Anybody got a carb?:D

[BIG BAD RED]

i think ur biggest performance gain would be to buy my r

[dirtdog]

Originally posted by ReDnEcK KiD
So far, I have a Wiseco 10.25:1 compression .50 over Wiseco piston. A small unknown cam, a full DG Exhaust, and a UNI filter. I am running 13 /42 gearing, and 20 inch RAZR's.

I'm happy with it, but it stil wont beat a 400EX :WTF: Is it in my gearing?? or maybe I need to Rejet? I'm tjinkign of trying some of the following :

I'd like to see about getting the head ported and polished.I know this has been asked before, but how much am I looking at for a good port/polish job? And how much performance gain will i get?

I also have been looking into a web cam. I have the hard weld rockers. Has anybody on here had any luck with a slightly bigger cam?

The reason I took it apart is because it dropped a valve. Were can I get oversized valves? or Titanium valve springs?

I was told stock 350X has a 138 or 140 main jet in it. With my piston, exhaust, and light cam, Can anybody tell me what a Good Jet size to start at when i re jet? I was thinking 148, but who knows? Also what is the slow jet? Will I need to change it to? I really have no clue how to jet

thanks for the help guys:D

[dirtdog]

thoought I would pitch my 2 cents.Was checking out the powroll package and though it cost some money I've been told that it is very effecient for the cost.they supply everything from carbs to piston and rings, cams,valve springs and jets.they seem to know what combo is the best for your type of riding."poweroll.com"