04 Honda TRX 450R Rebuild Thread

[smithn1683]

I Just purchased a 05 Honda TRX 450R for $2200. How ever the four wheeler does need some work! The body is in good shaped aside from a crack in the rear plastic and a bent and cracked sub frame. Now to the motor, It is 100% apart. It has a bad crank bearings, bad head, and bad cylinder, other then that it is in good shape. It did come with some extras like a 13:1 piston, stage 2 cam, 2 sets of ITP reinforced rims, Nerfs, and handle bars.

I have created this thread to show the rebuild of the motor and gain help from people who have done this before. Here are some pics to start the project off. I am going to start with putting together the clutch basket and transmission.

I also have just purchased a complete head for $250.00 This brings the total spent so far to $2,450. The object is to make this a budget rebuild spending as least possible.

http://www.jeepforum.com/gallery/files//7/6/5/6/0/TRXSubFrame1.JPG

http://www.jeepforum.com/gallery/files//7/6/5/6/0/TRXMotor5.JPG

http://www.jeepforum.com/gallery/files//7/6/5/6/0/TRXMotor6.JPG

http://www.jeepforum.com/gallery/files//7/6/5/6/0/TRXMotor4.JPG

http://www.jeepforum.com/gallery/files//7/6/5/6/0/TRXMotor3.JPG

http://www.jeepforum.com/gallery/files//7/6/5/6/0/TRXMotor2.JPG

http://www.jeepforum.com/gallery/files//7/6/5/6/0/TRXMotor1.JPG

http://www.jeepforum.com/gallery/files//7/6/5/6/0/TRXFrame1.JPG

http://www.jeepforum.com/gallery/files//7/6/5/6/0/TRXFrame2.JPG

http://www.jeepforum.com/gallery/files//7/6/5/6/0/TRXFrame3.JPG

http://www.jeepforum.com/gallery/files//7/6/5/6/0/TRXFrame4.JPG

http://www.jeepforum.com/gallery/files//7/6/5/6/0/TRXFrame5.JPG

[rap169]

looks like you got your hands full there. Hopefully all the parts for that motor are there and not missing any. Good luck

[Houser450]

wow,a little ambitious are you

[smithn1683]

eh, it wasnt a bad buy not a great one but not bad. The last four wheeler I bought was the same way. I enjoy working on stuff like this that way I know the motor inside and out.

[450R_lover]

just weld up the subframe since this is a budget build. On the engine i'd get online and find a parts fiche to look at. And use a factory service manual.. it should help you find out where all the parts go and what is missing.

[N300exJ]

Other stuff your gonna need:

New center cases 400 to 600 for both

New crank 200

New crank bearings 120

complete gasket and oil seal kit 100

also a new oil pump gear,

i also recommend a new oil cooler, timing chain, tensioner

pretty much it comes down to your gonna need another 1000 to 1500 to get it a tiny bit more reliable. but in the end get ready to spend a ton of money keeping it running. IM gettin rid of mine because its to much to fix all the time for the little bit of riding i get to do with it. If i were you id fix it and sell it or part it out as is. theres no such thing as a budget 450r.

[smithn1683]

why would I need a new center case? and I can get a hole crank with the updated bearings for $190 from service honda. why would I need a new oil cooler and pump?

[N300exJ]

The cranks throw the lower connecting rod bearing because the main crank bearings walk. They pretty much move all around in the cases. It only gets worse which causes the lower rod bearing to go faster each time it goes. so the center cases need to be changed if you dont want to tear it down again 6 months to a year from now. when the lower rod bearing goes the thrust washers grind up into nothing and send metal shaving throughout the entire engine. which equals in alot of cleanup. the metal shaving get into the oil cooler and can cause damage later on even flushing the oil cooler out isnt 100%. Just spend 100 bucks and get a new one. The metal shavings get in between all the gears and the smallest one is the oil pump gear. there is a small chance it can even slightly fracture that gear and cause it to fall apart later on in life(toasted engine). metal shavings get all in the timing chain and can cause premature wear of it. its all for insurance in hopes that the engine will last longer next time. the more you mod it the faster it goes boom each time. its just a never ending nightmare that requires $$$ to make it go away for a lil while.

[400exrider707]

Originally posted by N300exJ
The cranks throw the lower connecting rod bearing because the main crank bearings walk. They pretty much move all around in the cases. It only gets worse which causes the lower rod bearing to go faster each time it goes. so the center cases need to be changed if you dont want to tear it down again 6 months to a year from now. when the lower rod bearing goes the thrust washers grind up into nothing and send metal shaving throughout the entire engine. which equals in alot of cleanup. the metal shaving get into the oil cooler and can cause damage later on even flushing the oil cooler out isnt 100%. Just spend 100 bucks and get a new one. The metal shavings get in between all the gears and the smallest one is the oil pump gear. there is a small chance it can even slightly fracture that gear and cause it to fall apart later on in life(toasted engine). metal shavings get all in the timing chain and can cause premature wear of it. its all for insurance in hopes that the engine will last longer next time. the more you mod it the faster it goes boom each time. its just a never ending nightmare that requires $$$ to make it go away for a lil while.


the center cases are fine, the crank is fine on it, but we are replacing it anyways just to get the updated sleeve. The oil pump should be fine, but will be replaced if necessary after inspection. This was a top end failure motor, not bottom end. The crank we are only replacing strictly for reliability. No need to get new cases. Metal shavings can get in anywhere and they can always be cleaned out if you spend the time to do it right. The oil cooler will be flushed using a transmission flusher. He is fully aware of the money thats needed to be spend to keep a 450R running and has decided its worth it. Its definitely not a never ending nightmare... if its built right and reliable it will easily last the season. No worries. Thanks for the compliments and suggestions so far guys. I will be lending a large hand in the rebuild of this as well.:macho


This should be a little faster than the 230....:blah:

[hendershot106]

Originally posted by 400exrider707
the center cases are fine, the crank is fine on it, but we are replacing it anyways just to get the updated sleeve. The oil pump should be fine, but will be replaced if necessary after inspection. This was a top end failure motor, not bottom end. The crank we are only replacing strictly for reliability. No need to get new cases. Metal shavings can get in anywhere and they can always be cleaned out if you spend the time to do it right. The oil cooler will be flushed using a transmission flusher. He is fully aware of the money thats needed to be spend to keep a 450R running and has decided its worth it. Its definitely not a never ending nightmare... if its built right and reliable it will easily last the season. No worries. Thanks for the compliments and suggestions so far guys. I will be lending a large hand in the rebuild of this as well.:macho




707---- nice to see u actually defend someone and their work.

usually this is where u bash someone and their ideas/experience.


n300exJ ---- just curious---

has this happened to a motor that u worked on,, had worked on,,,??????? and if the cases were questionable why not have them checked/xrayed??????


smith---- (during your rebuild it would be worth the 20$ to order the sparks heavvy duty clutch springs and take a extra fiber plate and replace the half size shutter clutch fiber and metal plate inside in your clutch basket) ((they are on sale right now 30$ off)--- and while u are repairing your subframe check your main frame for cracks by the headstay,, underneath footpegs,, where the cast and tubulars meet on the top back of the steel frame,, in between the top rear a arm mounts---

[400exrider707]

Originally posted by hendershot106





smith---- (during your rebuild it would be worth the 20$ to order the sparks heavvy duty clutch springs and take a extra fiber plate and replace the half size shutter clutch fiber and metal plate inside in your clutch basket) ((they are on sale right now 30$ off)--- and while u are repairing your subframe check your main frame for cracks by the headstay,, underneath footpegs,, where the cast and tubulars meet on the top back of the steel frame,, in between the top rear a arm mounts---

The frame is in good shape. He bougth this off a mutual friend of both of ours. It was raced for a very short amount of time by a local B level racer. He had a rev box on it with no rev limiter as well as a cam. The valves floated taking out the piston, head, and cylinder. This was not a bottom end failure motor, but like I said we will replace the crank and crank bearings as a precaution seeing as its already apart. After all of this happened to the motor, the last owner left it sitting with a blown top end and went out and purchased another four-wheeler. This quad really doesn't have a lot of time on it. It will be a fun project.




Originally posted by hendershot106
707---- nice to see u actually defend someone and their work.

usually this is where u bash someone and their ideas/experience.


I will defend anyone and their work if its done correctly.
The only things you will find me "bashing" are inferior products and people giving wrong information. I guess if thats what you consider bashing, them I am a basher!:devil:

[hendershot106]

u and smith gonna have any fun with that head and a dremel tool---???????-- (at least cleaning up the castings while having it apart??????)

[hendershot106]

also--- if u two need any stock parts for the rear end--- i have some stuff laying around----locknut,,,, brake hub--- carrier-- extra hubs-

[400exrider707]

Originally posted by hendershot106
u and smith gonna have any fun with that head and a dremel tool---???????-- (at least cleaning up the castings while having it apart??????)

perhaps... I haven't seen the head myself yet. This is his first real build. He has been tinkering a LOT with a quadsport 230 and has a very good understanding now of whats going on in the inside. Now for the real quad...:devil:



Originally posted by hendershot106
also--- if u two need any stock parts for the rear end--- i have some stuff laying around----locknut,,,, brake hub--- carrier-- extra hubs-

Thanks, we'll keep you in mind if we need anything.

[smithn1683]

yeah this isnt my first time tearing into a motor, I know the ins and outs. As far as the head goes Im not going to fool with it I already have another head with valves and everything in it. That head might be able to be salvaged the valve seats are still good. Most of the damgage is in the center of the head. As far as the clutch goes the plates are in great shape Its easy enough to replace those after I get the motor all together, we are only going to replace failed or high risk of failing items right now. I want to get it running, broken in and a few hours of riding before I really start buying after market stuff.

707- He took that rev box off right?:eek2:

[400exrider707]

Originally posted by smithn1683
yeah this isnt my first time tearing into a motor, I know the ins and outs. As far as the head goes Im not going to fool with it I already have another head with valves and everything in it. That head might be able to be salvaged the valve seats are still good. Most of the damgage is in the center of the head. As far as the clutch goes the plates are in great shape Its easy enough to replace those after I get the motor all together, we are only going to replace failed or high risk of failing items right now. I want to get it running, broken in and a few hours of riding before I really start buying after market stuff.

707- He took that rev box off right?:eek2:


Well not off, it wont run without it, he had some aftermarket knock off POS that apparently didn't even have a limiter set on it... unilmited revving....yeah theres a great idea on a four-stroke....

[smithn1683]

Is the stock one back on though? yeah I am def not running something with no rev limiter. He told me the reason it blew up was farmer worked on it and had no idea what he was doing. Should of bought his its just sitting in a field I guess.

[400exrider707]

Originally posted by smithn1683
Is the stock one back on though? yeah I am def not running something with no rev limiter. He told me the reason it blew up was farmer worked on it and had no idea what he was doing. Should of bought his its just sitting in a field I guess.

No, the first time a valve clipped the piston and bent, but no damage was done other than the valve, he tried kicking it over but the vale was hitting the piston so it wouldn't budge, it was locked up in a way, which was good because it prevented further damage. Well farmer only replaced 2 valves and left the other two in, so the very next time he rode it it did the same thing, except this time was running it WOT down the lake... yeah when valves start making contact with pistons running 10Krpms it isn't pretty... I do believe the stock rev box is back on it, but will double check.

[smithn1683]

Ok as you can see I have all the parts strewn around my work bench. After thinking about the easiest place to start, it came to me CLUTCH! Here are break down pics as per the fiche Let me know if you think I have something wrong or missing. #20 lock washer is pretty bent up and will have to be replaced I do have the judder springs reversed in the pic but they are right in the basket.
http://www.jeepforum.com/gallery/files//7/6/5/6/0/Clutch1.JPG
http://www.jeepforum.com/gallery/files//7/6/5/6/0/clutch2.JPG
http://www.jeepforum.com/gallery/files//7/6/5/6/0/clutch3.JPG
http://www.jeepforum.com/gallery/files//7/6/5/6/0/clutch4.JPG

[400exrider707]

That washer is supposed to be bent up, it is a lock washer. The tabs on the washer get folded over to literally lock it in place. You are supposed to replace them after every use, but just use your judgement, if it looks like its going to fall apart, dont put it back in. I've re-used them plenty of times in the past. Also you wont be able to assemble the clutch like this, you need to put the basket into the motor and lock it down before you can start throwing the plates and such on. Just to clarify for everyone else, the judder springs aren't really a "spring" They are #5 and #12 on the fiche.

[smithn1683]

Nah it def needs a new lock washer who ever took it off last bent the metal on it really bad it wont clip back into place. there is a few other odds and ends parts like that too. You can kind of make out from the pic that the sides are bent up and the metal is ripped.

[400exrider707]

Originally posted by smithn1683
Nah it def needs a new lock washer who ever took it off last bent the metal on it really bad it wont clip back into place. there is a few other odds and ends parts like that too. You can kind of make out from the pic that the sides are bent up and the metal is ripped.

It doesn't look that bad in the pic... they get torn up taking them on and off, but go ahead and get a new one if you wish, I cant knock you for wanting to do it the correct way. Also those pics of the cylinder you sent me, post them up here and see what everyone else thinks. I think its a waste to put anything other than a new one on there, but go ahead and see what other people think...:cool:

[trx250r180]

i tossed those judder springs with my 05,and installed an 05 crf 450 clutch,has a little stiffer springs ,and the engine feels more powerful now,i think the judders are desighned to let clutch slip a little,and you dont use the thin friction plate ,replace with a full sized one, the crf clutch uses all same sized plates similar to a 250r engine,also my factory clutch had the most outward disk in that little slot notch on end of clutch basket fingers

[400exrider707]

Originally posted by trx250r180
i tossed those judder springs with my 05,and installed an 05 crf 450 clutch,has a little stiffer springs ,and the engine feels more powerful now,i think the judders are desighned to let clutch slip a little,and you dont use the thin friction plate ,replace with a full sized one, the crf clutch uses all same sized plates similar to a 250r engine,also my factory clutch had the most outward disk in that little slot notch on end of clutch basket fingers


This quad will remain mostly stock so no need for a harder grabbing clutch... yet... trying to keep the cost down. Good catch on the last plate, didn't see it. Shouldn't really make a difference but thats how it is supposed to be.... N8, the last friction plate, rotate it slightly so that the tabs are actually inside the fingers of the basket.

[trx250r180]

i think if looking a inexpensive upgrade ,you can buy a single friction plate for about 10 bucks at honda dealer and replace judder and thin inward disk if anyone wants a better grabbing clutch for cheap upgrade,i was also running the honda 1040 oil in gold bottle and my clutch was getting pretty hot ,i switched to the dumonde tech in trans side i was running in my 250r ,seems too run cooler now

[400exrider707]

Originally posted by trx250r180
i think if looking a inexpensive upgrade ,you can buy a single friction plate for about 10 bucks at honda dealer and replace judder and thin inward disk if anyone wants a better grabbing clutch for cheap upgrade,i was also running the honda 1040 oil in gold bottle and my clutch was getting pretty hot ,i switched to the dumonde tech in trans side i was running in my 250r ,seems too run cooler now


We run Honda red bottle tranny oil for the tranny sides. I have recently switched to klotz trans oil on mine, didn't really notice a huge difference. The honda stuff is pretty good.

[hendershot106]

u may wanna check your manual--- im pretty sure mine says not to run transmission oil--- it says to use 10w-40 without the molybdenum additive in it

[400exrider707]

Originally posted by hendershot106
u may wanna check your manual--- im pretty sure mine says not to run transmission oil--- it says to use 10w-40 without the molybdenum additive in it

Whats the manual? People still read those?:blah:

Thats a recommendation... how many people do you know that even run Honda oil in there? A LOT of people run the transmission oil in the tranny side, its quite common, and I noticed a drop in false neutrals once I switched. Definitely a better oil to be using IMO than 10-40. The higher viscosity helps with all the shear stress created in the transmission.

Here's the klotz I run. Try a tranny oil hendershot... I believe there are more people on this site running tranny oil than standard 10-40.

[400exrider707]

Here's the Honda red bottle stuff... this is made for two stroke transmissions where the motor oil and tranny oil are separate.... the only reason most quads use a 10-40 is because the tranny and motor are all one oiling system. Notice the shapes of these bottles make it much easier to pour in the tranny fill area.

[trx250r180]

i like the red honda stuff,on my 250r my oil was getting clutch color fairly quick ,aftercouple races,lrd in oregon recomended the dumonde tech and my oil seems to stay cleaner longer now so ive stuck with that kind,is a little more expensive but if can get longer ride time between changes kinda evens out in the end

[smithn1683]

Just dropped 500 bucks on it for a new "updated crank" cylinder, rings,crank bearing, and a few other parts I noticed where missing. I also noticed I am missing the main shaft of the transmission! Not a Good thing. I called the kid and hopefully he will find it. This project has just taken a turn for the worst.:mad: Been rolling around the idea of just buying a bottom end or a whole new motor:rolleyes:

[hendershot106]

Originally posted by 400exrider707
Here's the Honda red bottle stuff... this is made for two stroke transmissions where the motor oil and tranny oil are separate.... the only reason most quads use a 10-40 is because the tranny and motor are all one oiling system. Notice the shapes of these bottles make it much easier to pour in the tranny fill area.

it always felt like my clutches would slip when i ran that red honda transmission oil in my 04 450r and my 05 250f-- thats why i run the 10 40--- but i just installed sparks heavy duty springs and replaced the shutter plate so maybe it will work better now== how many sets of clutches have u went through so far in how long u have had your 450-?

[hendershot106]

Originally posted by 400exrider707
Whats the manual? People still read those?:blah:

Thats a recommendation... how many people do you know that even run Honda oil in there? A LOT of people run the transmission oil in the tranny side, its quite common, and I noticed a drop in false neutrals once I switched. Definitely a better oil to be using IMO than 10-40. The higher viscosity helps with all the shear stress created in the transmission.

Here's the klotz I run. Try a tranny oil hendershot... I believe there are more people on this site running tranny oil than standard 10-40.

hehe-- i looked at my manual--- its says to run one of three--- tranny oil,,, 10 40 or 5 30 --- just not anything with the molybdenum additive--

[smithn1683]

*Waves Magic Wand*

http://www.jeepforum.com/gallery/files//7/6/5/6/0/smtrx450r.JPG

:D

[400exrider707]

Why'd you take the pink streamers off the handlebars? :p

[smithn1683]

Gave them back to squirrel they where to much horse power for me.

Grab yours this week so we can go riding! It's not just a garage decoration you know.:devil: