?'s about a mild 350x build

[patrickkomar]

my x makes me really happy most of the time but there have been a few times it's left me wanting a bit more. so after some thought and research here is what I've come up with as the winter project. first and foremost the main goal of this is to keep stock reliability wile adding some more power. I want to keep the boar stock and just raise compression up to 9.5:1 or 10:1( this may or may not be doable have not found the time to look around to see if wiesco makes a piston to do this), next i was looking to add a powroll midrange grind cam with there springs and retainers and letting them reface my rockers. wile my rockers are gone i would like to have the valves& seats ground and head ported and polished. as add on's i was thinking along the lines of the 400ex carb and header pipe. would this set up benefit form a lightened fly wheel and is there a better then stock intake boot that would help this set up? any ideas about my plan feel free chime in with your 2cents I've never done a 4 stroke build up were it wasn't more than just new rings and piston so i may be way up in the night about this all.

[NOS_350X]

I feel that your probably over doing things that dont need to be done.

First get an exhaust,
Second get an airfilter
3rd lighten the flywheel
4th get a carb,
5th piston
6th Camm it
7th port/valve work

You didnt say if right now you have an exhaust or filter, Those 2 are musts.
They flywheel will do numbers to the motor.
400ex carb is just handy with performance as a side effect.
You want stock like realibility,stop here
The compressions your talking about you wont notice any gain unless your motor is that worn out.
Yes cam's are nice just a decent dropin would suit you good, no sprigs needed or try a ft cam then you dont need to hardface eather.
Porting is really the last step if you want more power before you go the big steps and bb/stroke it.

[patrickkomar]

sorry I left out some things. this bike has a carb that I have no idea were it came from or what size it is, I do know this it's crammed very tightly in to the intake boot. next there is a slip-on on my x but just like the carb it was on it when i got the bike and i can't seem to find any markings on it. the air box holds a k&n with an outerwear prefilter but i do run the lid and the snorkel! The bike seems to have plenty of power and dose not smoke so i don,t think it's worn out. I ride in the sand quite a bit so I'm just hunting for more power with out having to go big boar! It was my thinking that the list of things in my post above would make the stock boar be as efficient as it can possibly be with out stretching the reliability to the point of being sketchy. Now for the next question you say upping the compression won't do any thing for me that a position and rings wont. It that due to the inability to adjust the timing or what?

[NOS_350X]

Your not going to notice much of a gain with the little increase of compression your talking about. Get to 11:1 or up and you will really start to get some gains. Less and it is like stock with not much extra pep.

If you can get a pic of the carb we might be able to give you a hand. The size is the biggest factor there which you would need to mic it.

Where do you want the power? That is really going to decide what and how you want to do everything to it. Most sand riders want topend power.

[Black Sheep]

When your building a four stroke motor the more you go the less reliable you get. I can bore a 350X to 500. it will be about as reliable as a two stroke.

so there has to be a compromise between performance and reliability.

I've found the best combination of increased power and reliability was this set up.

done in the following order.

air filter, Uni dual stage, airbox no lid.

Pipe, I built my own from DG/Cobra/supertrapp. Cobra header, DG mid, Cobra muffler, Supertrapp insert.

carb, I used to use 36mm PD, But now i would use a 37mm FCR

Piston, wiseco 10.25:1

cam...megacycle part # 162-30. With H.D. valve springs This cam is specifically made for the 10.25:1 piston.

Porting, (unless you have a flow bench this is best left to someone who does)

H.D. cam Chain, I think EK has them still

13/38 gearing. go sidewinder and you'll never replace them again.

H.D. clutch springs with stock Honda plates.

i left the flywheel stock because were i ride and my style i like the low end torque. (IE: instead of screaming 3rd i torque through in 4th or 5th)


This set up will get you around the same H.P. as a 250R. Yet you will still be very reliable. the wiseco piston is forged and much better material then stock. The cam retains the use of the stock Honda valve guides which are some of the best. any larger cam and you need to either shorten them or buy aftermarket ones. either way reliability goes down, worse with the aftermarket guides. you can also Run pump gas...93 or above...with this combination. any higher compression and you'll need race gas.

I ran this set up for over 20yrs and never once had a motor failure. I replaced the rings once, then piston and rings later on. eventually in 02 the small end of the rod was worn out and i had to rebuild the crank.

[NOS_350X]

Lightning the flywheel you dont loose any torque. Just makes the mottor rev faster. Little more common for an at idle stall. But seriously when are you EVER at idle? I will continue to say this, The flywheel mod is the single best thing ive done. Yamahondaman on here does them cheap, he is who did mine.

You have to find out the power you want, build your motor for that type of power. and ask questions.

[Black Sheep]

Lightning the flywheel you dont loose any torque.

The flywheel stores energy. the lighter your flywheel the less energy is stored. In low rpm situations the more energy you have stored the more torque you have.





Just makes the mottor rev faster. Little more common for an at idle stall. But seriously when are you EVER at idle? I will continue to say this, The flywheel mod is the single best thing ive done. Yamahondaman on here does them cheap, he is who did mine.

True, a lighter flywheel Will rev quicker thus providing quicker acceleration



You have to find out the power you want, build your motor for that type of power. and ask questions.

EXACTTLY,

I like a good all around motor in a 350X. smooth power always on tap. I used my 350X's for all around play riding and woods racing. in those situations a more manageable motor is the key.

if i wanted fast acceleration or a pure Race motor i wouldn't even waste my time with the 350X...that's what that 250R is for.

[NOS_350X]

The next X you build when your done ride it, Then lighten a flywheel and ride it again. You WILL like it. There is really no bad side effect to it. The flywheel on the x is so heavy it "stores more energy" than what the X can use.

IMO you cant get a 350x motor to the point where its unmanageable. Rember i ride a 60 hp shee. Any 4 stroke is more manageable than that.

[Black Sheep]

Well it comes down on type of riding. In tight woods situations a lightened flywheel is a disadvantage. And a 60H.P. banshee is worthless. its not about how much power you have but how effective that power is. In my early years I used to run a lightened flywheel and ride in the higher RPM range. Then i wizened up and put the stock flywheel back on a learned how to ride a gear or two higher and torque through.

Of course this is for tight woods/off road. Riding on a track is a different story. I only did that on my 350X for one year. after that i Used 250R's for serious racing.

nowadays i don't bother with either one.

patrickkomar, eitherway you have some information to help you decide whats best for you.

[jenndnn3]

Out of all the TRIKES out there this is the one I would NOT build up...

YOu really have to be good at it to maintian its reliability... I would not crack open a perfectly awesom running 350X (but then that is just me and again this is the ONLY trike I wouldnt touch)
Furthermore for the amount of money you are about to dump into it,, you could fair better with something a quicker or a little more cc's... you pretty much already have the slipons without digging into the motor..
Just my humble opinion
The carb will have some #'s and letters on it.. that will help Identify it..look around the top of the bowl area.
Or you could mike it..

[SWIGIN]

post #3 http://www.3wheeler.org/vb/showthread.php?t=33364


i wouldnt say a 350x motor takes anymore to maintian then any other motor.....just change the oil and filter often (as you should with any 4 stroke) and your set

[patrickkomar]

OK guys i tracked down the carb #s today! It's a keikhin part# DG8AAAG and on the card body it's self just above the part# there is the letters PE. As far as wear i would like to build power its mid to high end for me. i don't want to kill all the low end but there's more than i need there right now. as for the pipe i looked it over again today and still could find nothing stamped in to it. It seems to be a well made pipe and it sounds great! so if it's not hurting any thing I'm fixing to leave it and just add the head pipe. I'll try and get some pic's put up of the pipe tonight, working 12's at the moment and just don't have a lot of spare time on my hand's.
P.S. I'm most defiantly not going to do the P&P work to my head I'll leave that to the pros.