Author Topic: Narrowing the rearend?  (Read 2321 times)

strkablaz

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Narrowing the rearend?
« on: November 22, 2007, 09:48:01 PM »
I am wanting to make the rear end narrower (FL350) so it will fit on the trails that are in my area.  This was my thought. Putting the 400EX rear hubs (4/110 pattern) and running a set of front rims and tires.  I figured it would make it 6.5 inches narrower.  I due understand that I have to machine the back of the hub so it will fit into the seal on the carrier.  Has anyone done this before or heard of it being done or is their already a hub out their that will work?

Weed

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Narrowing the rearend?
« Reply #1 on: November 25, 2007, 11:04:31 PM »
I have thought about changing the hub as well to fit more common rims like 4/110.  4/130 are kinda hard to find used.  This would be a good excuse for me to experiment.

I need a hub to hack on....

So where do you ride?  Most trail parks are limited to 50 inches to keep us out.

Weed

strkablaz

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Narrowing the rearend?
« Reply #2 on: November 26, 2007, 09:34:18 AM »
I was wonding if anybody else had the same problem that I was having.   I live by Amarillo, TX.   We ride at the Red River by Memphis, TX,  lake MacKenzie and hope to start ridding at Little Sahara this coming spring.

hoodlum

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Narrowing rear
« Reply #3 on: November 26, 2007, 05:49:31 PM »
I think Rocketman uses an adapter on his rear hubs that changes it to a 4/110, and uses narrower wheels....It is just a wheel spacer with studs in it......Not sure where he got it...
Hoodlum

nuke em

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Narrowing the rearend?
« Reply #4 on: November 27, 2007, 08:28:03 PM »
I traded Allen Rhien even up for a set of hubs that were 4 on 110. I do not remember where he said he got them. I can email him and ask if you guys really want to know.

Gary

strkablaz

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Narrowing the rearend?
« Reply #5 on: November 27, 2007, 10:26:35 PM »
Nuke Em,  I would like to know where he got them or who made them.

I was also wondering what are some mods that I might need to do now that I have the motor disassembled.  I need a new rod, piston, and will be boring the cylinder to the next size.  

I know about the oil mod, adding the holes to the piston (exhaust), make a relief on the exhaust port.  

I am looking for more bottom end than top.  I have a 94c clutch, water cooled head and DG exhaust.  

Any ideas to help it out?

Brian

nuke em

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Narrowing the rearend?
« Reply #6 on: November 28, 2007, 11:10:54 PM »
First off, WELCOME to the site! I should have said that earlier. I will ask about the hubs and let you know. Sorry, this will be a little long winded too so grab a fresh beer. LOL :P

  I will give my 2 cents worth on 350 mods. I have about 15 years of messing with the 350s and have have found out (mostly the hard way) what works well for my riding style and areas/terrain(3,000ft-9,000ft above sea level). I have been on a tight military budget so most parts I use are either fabbed or bought used from Ebay. Not everyone will agree on the best mods, or good mods so use whatever you like. These are my personal suggestions and opinions. Hows that for a disclaimer! LOL :lol:  

1. Air Box Mods. The factory airbox, snorkle and tail light box. Great for keeping out dirt, mud, rain ect., but extremely air flow restrictive especially in hopped up machines where you need increased air flow. There are alot of posted pictures of dual snorkle mods, each a little different and all fix the restrictive problem. Probably best bang for the $15 spent!

2. Air Filters. Hot debate topic with different views, all require proper oiling and regular cleanings, especially in a dusty enviroments.

In box, Factory foam filter--probably the best filtering but most restrictive becuase of the metal screen cage inside. Dual stage, Uni foam filters--most commonly used, great flow and good filtration. K&N filters-- most air flow but least filtering even with the optional outer precharger covers. most expensive also.

(No box) pod filters--again, debatable, you may lose power by removing the box because of the two stroke pulsewave/resonance, loosing the box makes access to the carb much easier, the filter is exposed the elements and needs to be covered when not in use, does not like water covered trails!

3. Carbs--again 32mm(stock)is too small for hopped up engines but fine for stockers. If you want your engine for torque(hard launches, steep climbing, ect) stay small 34-36MM, if you want your engine to rev high and really pull on top end, go big 38,39MM, +. Ofcourse you will want a port job and an exhaust pipe to match, rev or torque.

The more modern flat slide type carbs give a better throttle responce. I prefer Keihin over Mikuni, but that is just me.

4. Exhaust pipes-- Stock works well and is the quietest but is very restrictive when hopped up. DG, PowerPros and Bills are some that I have tried, and all give good gains. The DG silencer(or lack there of) is horribly loud and has to be swapped out ASAP. Again, some have been tuned/designed for rev or torque.

5. Reeds--Stock are steel and very trust worthy but restrictive on built engines. Boysene makes replacement fiberglass reed pedals for the stock cage in either rev or torque pretty cheap. Also most ATC/TRX-250R, CR250 and pilot reed cages will fit in the 350. I prefer the 4 pedal Cr250 cages(best flow). I also use a straightened neck boysene Rad Valve, G-3 and Delta V Force reeds, all with increased power and throttle response over stockers. There has been some verified cases of the V force cage getting sucked into the engines. I don't recall if they were version 1,2, or 3. I have used my version 2 for well over 3 years with no problems, yet. Knock on wood.

6. Clutches--Again another topic of debate, Salisburys(stock) good ol reliable but a lower engagement boggs the engine for racing. 94C-great all round clutch, draw backs are its not really tuneable. 102C- great for racing because you can adjust engagement and different areas of the powerband by changing springs or cam arms. Draw backs-expensive, without the dustcover can wear parts quickly. HRD & Alt--good simple design clutch(very similar to the 94C) except you can adjust puck wieghts for tuning, priced between the 102 and 94. Drawbacks tends to tear up the "D" slot on the cover and possibly has ties to Pilot main bearing failures, none know on 350s yet.

7. Porting-- The heart and sole of the engine, can be mild to full race(wild). If not done correctly, you can ruin an engine. It needs to be done by a knowledgable person, not a shadetree(like me). You can take a dremel and clean up casting flaws and other imperfections inside the jug, polish up the exhaust port and make better flow thru the engine(better power) but avoid changing the size and shape of the openings. That is the timing and could spell disaster if not done correctly. There are alot of articles written on porting work so if you want to do it, better do the homework.

8. The little tricks-- here are just a few I use. The stock head gasket is actually three layers. I use only 1 which bumps up the compression some. Always use a quailty synthetic oil at 40 or 32:1 with fresh premium gas. Run a liq cooled head and radiator to help control heat especially with a built up engine. I use an EGT and a water temp guage to help monitor things. Run .190 aluminium rims and lighter weight tires if not in rough/rocky areas, less kenetic mass to spin equals more power to use.

Theres a good start of info to absorb and I am sure other will add to the list too. I am sure I have forgot things too. Good luck,  :wink:
Gary

strkablaz

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Narrowing the rearend?
« Reply #7 on: November 29, 2007, 09:58:59 AM »
What silencer can I use to replace the DG silencer?

nuke em

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« Reply #8 on: November 29, 2007, 09:00:27 PM »
I have used mainly FMF brand silencers before with the DG. You can get em used fairly cheap on Ebay. Mine was a Turbine core, I think for a 250R. They need to be a larger CC engine type to mate up with the DG. CR250,500, TRX250R, KDX, ect, no 125CCs. Been there, done that. The longer, the quieter or so I am lead to belive. You will have to fabricate some kind of mounting system for it too.

I'll try to find a picture of my setup for you later.

Gary