# 300-fiddy build thread - Full custom IRS +6, & 350 foreman engine swap.



## JPs300

I bought the bike a few years ago as a basically stock '96 Honduh 300 with a blown rear diff. Did a 2" lift, 26 vamps, 250 big red(atc) cam, ported head, 1.5" head pipe w/ harley muffler, 300ex gear reduction, dual 1.5" center snorkels and a big audio system. - There were a few renditions along the way, but just a typical 300 mudder. 










I accumulated parts to get a bit wild with it. Another front diff & axles, some kodiak IRS rear spindles, 4 rincon rear shocks, and an '86 350 foreman motor. I ordered some DOM steel tubing (1x.095 for the frame and 3/4x.095 for the arms/brackets) then went ape-nuts with the plasma-cutter and MIG. 

Stock frame:









after plasma:









What I saved for re-use:









What I trashed:









I welded the lower motor mounts onto new tubing for crossmembers, then set it on my lift and mocked-up the upper rails with a 2" body lift. 









I built the new front frame 3.5" longer between the front and rear a-arm mounts. This widened the lower a-arm for added leverage with extended arms, and allowed me to move the rear upper mount ahead of the steering stem(like a foreman, rancher, basically anything except a 300), thus negating the need to twist the upper arm and/or tie rods around each other.









I sleeved the axles with 1x.134 DOM tubing adding 6" of length. The stock joints will go just under 35* maxxed out, so I set-it up to be roughly 33-34* at full suspension extension thus putting them at roughly 32* at ride height. - I built a channel to hold the wheels, thus using it to square my alignment. I bolted the hubds, spindles, and axles in place and built the arms to suit. I built the arms arched for the added ground clearance. 













































I set the front shocks at 68*, creating a little less leverage than most big lifts do, thus allowing a bit smoother ride at the sacrifice of a little height. Hind-sight with my big audio system I could have went 70-72* and still been smooth enough, I may later throw in a spring spacer to stiffen it a touch, don't really care right now, but might if the springs settle any(all new shocks/springs). 




































Then on to the rear.


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## Polaris425

looks good so far!


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## JPs300

I wanted as much space as possible between the engine and rear diff, as I have an idea up my sleeve that would occupy this space in the future. I set the rear diff back behind axle centerline roughly 1-2", allowing for more room. 









With upper a-arm crossmember in place:









From behind, the almost kinked bends on the "u" pipe were actually done on purpose to keep everything tight. With the stock trunk in the plastics, the shocks, and the exhaust(s) everything can get pretty tight back here.









My "alignment rod" to keep the pivots on plane correctly:









Simple rear spindle mounting. I used 3/16 plate and cut the tubing lengthways on center, then just slid the tubing on the plate and welded. I trimmed off the excess when I did the final welding and paint work. 




































The rear shocks mounts ended up a lot more complex than I thought. Getting them mounted strong enough, under the fenders, and allowing for room for the exhaust is pretty tight, especailly with the long rincon shocks I used. 


















The "final" frame:










The emtpy frame, but w/o the upper rear motor mounting:









Some misc shots that are often asked about.

Steering stem extension for the body lift:









Front over-view:









Front suspension w/o the wheels. - I used the OE ball joint mounts, but re-angled them so they sit neutral at my ride height:








Cut down stock upper ball joint mount:









Honda front hubs, right one machined to fit the yami rear spindles:


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## JPs300

For the front tie-rods I used OE joints, cut the stock threaded rod and sleeved it with the same 3/4x.095 DOM that the arms were built from. I s-bent the tubing so that the tie rods sit neutral at ride height(just like the ball joints).









I already posted pics of the head port work in the other thread, but here's the misc motor stuff. Wiseco 10.25:1 piston, Web "180" all-around performance cam, EPI 2k stall clutch springs, and 300EX primary for a 35% reduction. It also recieved all new seals/gaskets, fresh valves & grind job, and a fresh timing chain. 









Getting the 350D motor to work with the 300's t-case is considerably more difficult than most people seemed to think. The 350 is physically larger, and the output shaft is lower than the 300's. I made a single offest tab that bolted to the engine and to the t-case, then built two other brackets that bolt to the t-case and the frame. I angled the t-case input downward to comphensate for the engine out-put height w/o altering the front driveshaft centerline. 









lower mount:




























I ended up in the bucket club! just under 17" of ground clearance to the frame with 27" vamps. 









Nice air-gap, those bucket factories better look out!









Whenever possible I use expanded metal instead of flat plate for skids/parts protection. It can gaurd most compenents just as well, and doesn't create as much drag when burried down in the mud.









My 2" flex hose snorkel coming from the air-box all the way to the 3" riser. 









My 2" vent canister. All my vent hoses run to here, then a single 1/2" hose runs up and hooks to the side of the 3" snorkel riser. i also use a carb drain check valve on the bottom to keep it empty but sealed.









I modified the stock 350 foreman head pipe to work at least for now. I built the frame to allow me to run dual exhaust if I feel like it in the future. Re-used my harley muffler for now, but it's likely to change. It's way louder with the built motor and the tone got a little higher than I like. 


















There was some more trimming and a few more braces added to the a-arms and frame before final welding & paint work. My buddy painted the frame and arms with POR-15, which when properly prepped and applied is basically as tough as powder coating. - I was on a time crunch, so everything is just glass black for now. I may add some color to the arms in the future.


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## JPs300

I'm pretty happy with the finished result. Went out for one good abusive test ride and broke the rear diff, lol. it was expected to happen, just not quite that soon. I have figured out the weakness of the stock diff carrier and have a few ideas up my sleeve to solve it for good. - With the rear completely barried I could shift into 2nd and light the tires from a dead stop. The plan is to go up to 29 s/w backs; I'm sure I could go larger but with them I'll be solidly over 17" of GC and the little extra gained by larger tires just isn't likely to be worth the added drivetrain stress/maintenance. 

Other than the diff, I had some carb issues which are already sorted, put the wrong pressure plate in the clutch pack resulting in no engine load release and thus a super stiff shifter, had the snorkel a bit higher than needed, and just had the oil cooler zip-tied up there. 

































































With the snork shortened some & oil cooler mounted -


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## hp488

That is a very good write up and pics. Turned out very good, wish I had the extra time to do that I have a rubicon I want to put IRS in the rear. Good job!!


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## bump530

looks like crap to me. i think my 2 year old has better fab skills than that....wait is this the lego build thread? no? dang...ummm lol

like i said before...looks great man


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## byrd

im thinking crush lock edl's would set if off now:rockn:


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## Polaris425

Turned out great! :rockn:


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## JPs300

Thanks for the kind words guys. 

Crushed EDL's would be pretty cool, but I ride mixed (not just mud) and don't really want to deal with swapping them around all the time. I was gonna cut my wheels down to 4-5" wide, but I think I'm gonna keep wides on the back so I'll probably keep my rears @ 7" and just cut my fronts down. - I was thinking about a EDL/27 wide combo, but I'm really liking the s/w 28 backs my buddy just put on his built eiger. 

One thing's for sure, it needs more tire. I'm sure I could pull 29.5's or maybe a little more, but I just don't see the extra .5-1" of ground clearance(over 28's) being worth the added drivetrain stress when I already have 17" of gc.


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## JPs300

I changed the snorkel riser a bit(shortened it some in both straight sections) and finish mounted the oil cooler with some custom bent 3/8 tubing with tabs welded on. I also built a custom muffler using a couple misc mufflers I had laying around and a section of 3.5" exhaust pipe; went from sounding like a 350 honda to sounding like a 350 chevy, lol. 

I probably won't see my new diff till the first part of next week though, then gotta sort out the machine work to add some strength into it. Was really hoping to have it in hand for the weekend, but I didn't get the ball rolling soon enough. - Need it in so I can final tune the carb. Got the idle issue sorted out so it fires and runs smooth, just need to make some WOT runs to sort out the main and then a couple good rides to dial the needle in. 

Got some clean eiger head-lights to mount in it(they were free, stock ones in good shape are $). They're slightly larger and a smooth clear lense; should be bright with the hyper-blue bulbs. I thought about going HID, but don't think the added voltage load would be a good idea my audio system already leaning on it.


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## bump530

well hurry up and get it done then lol...


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## greenkitty7

where you gonna put that paddle you speak of? and why?


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## brute for mud

what kind of angle are the axles at i would watch them looks awsome


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## byrd

i think i read he put ride height at 32 degrees


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## JPs300

Axles are 33-34* at full suspension extension, thus roughly 32* at ride height. 35* puts the shafts against the cups with the stock joints. - If they give me trouble I have Turner's phone number. 

The paddle is in the distant future; not something I'm worried about for a while. I'm going to put a 14" paddle between the engine and rear diff, using a shaft and set of pillow-block bearings. I'm going to build an enclosed chain drive off of the right rear inner CV cup to drive it. - Even with a big IRS lift you can still lay frame in much of the stuff we ride down here. With the paddle, it will only pull harder as it gets there.


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## JPs300

HAHAHAHA!!!! 
350 + 35% reduction = 2, rear axles = 0

Apparently 1x.134 tubing ain't gonna cut it out back. I put it through *a lot* more than I was planning yesterday. The bike performed really well for me being pretty easy with my thumb, pushed through a couple holes that few others even tried. Climbing out of a deep but hard-bottomed hole at the end of the day it started struggling; seemed odd till the rear tires surfaced and weren't turning. I thought for sure I had just killed another diff, but though it odd that it hadn't made and was not making a single sound. I climbed around onto my front d-ring to get the front tires dug in and eased it out, found both rear axle shafts dangling between the a-arms. It snapped the tubing clean just below the plug welds. 

With the spool out of the front and a shimmed posi back in, riding it home was "fun"....torque steer in sugar sand is a biotch! - All in all a really good day. Bike is running well, slight stumble just off idle and a little shift issue, both of which aren't really enough of an issue to mess with right now. I've got some stuck pics of my buddy and he took some video on my phone of me going through a 25-30' long hole full of some moderately thick pb mud. The pics I can do, but no idea how to upload/host the video.


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## speedman

yooo did you finish bike already? when we riding? i got a big group ride coming up if you wanna go.


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## JPs300

Finished it and broke it twice already, lol. When/where ya'll rolling? 


Couple video's posted by my buddy Mike. - 
Walk around while I was doing some tuning runs(wideband hanging up by the snorkel):




 
and a little playing(note, g'zone phone not the best camera):




 
Lastly, my boy stuck in some of the thick stuff. This is the sra kodiak he built for his wife, pretty tough little bike. It was still turning the 28 laws, but couldn't climb out.


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## speedman

we are trying to go next weekend, ima see if i can get saturday off to go whole weekend to holopaw.


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## JPs300

Just looked that up, Looks like some good riding, but a bit too far for me right now on my new budget.


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## speedman

yeah i feel you, im thinking of not going cause i need to save money for ryc.


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## JPs300

I'm trying to make RYC, but not sure how this rear axle deal is going to go.


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## lilbigtonka

jp make it and break it lol jsut be at ryc.... i got a 300 you can ride i just cant promise it will run lol hahahaha


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## JPs300

well, I spent too much time on my buddy's MR this weekend...now I'm jones'n for a big bore, lol. 

Gonna let this and my harley go in favor of a big bore for me and something for the wifey. Probably be yami's or can-ams.


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## pitbullmike007

lol, i feel ya , them bb's are addictive.. but expensive. lol.. keep me posted on what u do with ur 300 and what u get,


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## bump530

dang JP...gonna get off the 300 bandwagon huh? the big bores are fun but i dont really miss mine too bad. i would get another one if i got it cheap enuf and had to rebuild it lol.


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## JPs300

Well, it sounds like I may already have a pretty solid offer of a built 686cc rhino & a nice 660 grizzly even up for my harley, thus I may let this go pretty cheap just to cover my pay-off on the harley.


That XMR is stupid fun, but I can't justify that kind of $ for quad. I think a grizzly with typical bolt-ons and a wet clutch delete will make me plenty happy enough, though it will probably also end up with +4" turners and some custom arched arms to suit.


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## bump530

you had me at 686 rhino LMFAO


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## JPs300

^ lols. 

I'm really hoping to catch a ride on a 660 sometime soon to make sure it will be enough to make me happy. Obviously it's not going to be an 800 rotax twin, but as long as I can snap the throttle and light up 29.5's(or stand it up on solid gruond when it can hook) I will be happy.


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## JPs300

I finally uploaded some "finished" pics. 

w/o the stereo - 


















As it rolls -


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## pitbullmike007

such a great lookin bike jp,, hate to c it leave,, if i had the cash id def get if off ya bro..


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## JPs300

Thanks Mike. - I'll probably regret letting it go one day, but the deal I have in the works is the most logical for me right now. This gone, my harley and it's payment/insurance gone, and a new bike for me and SxS for the wifey. Too much of a win/win situation to justify keeping the honda.


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## pitbullmike007

naw i feel ya bro, id prob do the same thing,, prob... lol.


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## 05camobrute

> My 2" vent canister. All my vent hoses run to here, then a single 1/2" hose runs up and hooks to the side of the 3" snorkel riser. i also use a carb drain check valve on the bottom to keep it empty but sealed.


How did u do the vent canister i want to do that to my honda, really good idea


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## JPs300

It's just pvc pipe with a cap on each end and some brass barbs screwed into it. Simple/straight forward and effective. One line runs from it up to the side of my riser to vent it out, while the check valve on the bottom allows anything(fuel slosh, light leak somewhere, ect) that gets in there to drain out.


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## cookster500

how do you sleeve the axles like that?


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## JPs300

Cut them in half and slide each side into a piece of tubing. I used 1" OD x .134 wall DOM tubing with four 3/8" plug welds on each end, offset 1" from each other on opposite sides. 

The fronts have been problem free, but tubing sleeved axles aren't strong enough for the back. I even tried 1-1/16 x .150 wall tubing and heat treated it to a rockwell grade "c"; still twisted the rears off within one ride. 

I just had a shop make me some "solid sleeves". They took 7/8" OD 4340 solid rod, "rifle drilled" each end to a 9/16"dia hole roughly 1-3/4 deep on a lathe, then turned my axle stubs(the cut stock halves) down to 9/16" and pressed fitted them. Same four plug welds on each end, TIG welded, then heat treated. - Solid bar instead of tubing, and 4340 is considerably stronger and more workable(better heat treat strength) than tubing. There's a 750 king quad running around down here with over 10" of lift with the same axle bars handling a gear reduction and 30" mambas, of course now that his bars hold his joints won't...lol.


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## JPs300

Well, I didn't like the above axles so went to 1-1/4" cold-rolled 4340 solid bars, heat treated to a rockwell "c" (same as truck axles) and managed to twist them off clean where they were machined down for the boot lip. - Did that a couple hours after twisting off the intermediate shaft, thus was increased load on them only being 2wd. Got a bit bound up in a rut and shocked them good of the clutch stall.

Motor is making great power, thus the 35% gr & clutch stall can really hit the drivetrain. I'm pulling the FS adds and going to let it sit a little while till I feel like messing with it again. More than likely it will see some custom Turner axles out back and be kept around as a back-up bike. Getting to the point where I have to much invested to just let it go cheap for no real reason. Was going to get rid of the payment on my harley, but eh, no biggie. 

pitbullmike should have some good video from this weekend. Probably even has me twisting the int shaft off trying to climb out of a bottomless pit......lol.


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## pitbullmike007

had fun bro this weekend,, still cudnt believe it broke them shafts like that,, shud post a pic of that lineshaft broken,, lol.. 

well heres a quick vid of clips put together of that day,, i did get a shot of u tryin to climb out that hole robert rutted out with the xmr.. lol.. i need to save up for a gopro cam for some better quality, than jus my iphone lol.. it loses so much quality when i have to convert them to .avi format for it to get edited in the moviemaker..


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## JPs300

Finally upload pics of my last set of axle shafts. - No possible way to build a stronger sleeved shaft, but now that the sleeves held the stock bar itself proved to not be up to the task of being in the back of this bike. 

I used 3/4" solid bar stock and split it in half for 1", then put the corresponding split on my stock stubs. 









I put two 3/4 schedule 80(perfect ID, so I went with it) sleeves on the shaft before welding the shaft sections together, then slid them out over the welds and welded them in place. They have a 3/8 hole on each end for a rosette(plug) weld, plus welding the ends. - As you can see in the second pic, these sleeves will go from outside to inside the boots. 



























I then slid a single section of 1-1/4"x.125 wall DOM over the split sleeves, from center of sleeve to center of sleeve. It has two 3/8 rosettes on each end, plus welding the ends. The finally result is a very beefy looking axle bar. 










After a few hours playing in some thick black muck, I splintered one of the stock stubs up inside the CV joint. - This is the second time twisting off the shaft itself. The first time it twisted roughly 1/2" from the end welds, thus I allowed that the weld hurt the tensile strength. These on the other hand were fully heat treated after welding(something I did a couple sets back w/ regular sleeves), and broke the shafts well beyond the weld area. 

Between twisting the solid one-piece bars off and then breaking these, I'm am 100% certain that the stock front axle bar size simply isn't enough for the back of this bike. - Especially since this set was hurt while in 2nd gear, as I'm still only on the 27's not the 29.5's this bike needs. The same moment one rear bar let go I grenaded a front joint, turning the most of the balls, the star, and the cage into un-identifiable metallic rice krispies......... 




At this point, the bike will be down for some time. I can't justify putting any more money into it right now, so it will spend some time stuffed away in storage. - I'm going to swap the rear diff out for a 350 rancher rear converted for IRS, then drop the $ for Turners all around. While doing so I will swap the front spindle for yami spindles/hubs, and swap the rear hubs to the yami ones as well. No point in making the axles & joints strong enough only to leave the small diameter stubs in the spindles.


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## JPs300

bump 

I fixed the pic links that got screwed by PB somehow. - Getting a little motivation to do something with this bike again, so probably a set of Cobra axles & some 30" shoes in it's future.


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## lilbigtonka

Bike is entirely to cool to let just sit there jp...get that show on the read so the ham and brute can take a break and we can show these boys what real bikes do lol 

the wetter the better


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## RYAN.

That's a nice bike man

—————SIGNATURE—————
HIS

2010 MUD PRO
SOON TO BE 3.6
HMF & PC3
30" MUNKIES
CLUTCHWORK
RACKED

HERS/KIDS

2006 400M
SOON TO BE 4.0
EXAUST MOD
RACKED
JETTED
29.5 LAWS


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## JPs300

I'm definitely considering a pair of cobra axles & a set of 30" interforces. - I think the AG type tire would really suit the look of a 300, and cut like dstelly does them they would pull *hard* on a gear reducted honduh. 



The hold up has been the rear drivetrain. I hate to buy a set of custom axles only to start blowing the diff again, and it's still a question in my mind as to if it's really strong enough.


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## bump530

You know who to call (and i think you might have the ability to do it yourself) to build a "irs" foreman 350 rear diff for that 300...that way you can keep you gear ratios the same


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## RYAN.

What kind of pipe bender do you use, you got me thinking hard about selling my mud pro and building me a 350 or 420 rancher


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## JPs300

I have two benders. An actual mandrel tubing bender & one of the cheapy "crossbow" type pipe benders. The good bender is nicer and I can bend around 250* w/o moving the tubing or dimpling it, but it's not as quick to work with. 

You could do this type of stuff just fine with one of the cross-bow types.


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