Rebuilding my 2000 Honda TRX 250 Recon. Need some help!

[Viktor_AZ 1]

Hi everyone, my name is Viktor.  I'm new to this forum and new to working on ATVs.      

 

I have a 2000 Honda TRX250 Recon that was sitting for about 8 years. I got it from a friend - he didn't want to spend any money on it and is not mechanically inclined.  I like tinkering on things, ended up pulling the motor, took the top end off and noticed that the piston was not connected to the crankshaft. Basically the connecting rod exploded inside the motor, metal chunks everywhere (probably was low on oil and/or revved too high). See photos.

I got this thing for free and don't mind putting a little bit of time and money to get it to run.  At this point, it looks like I'll need to repair/replace the cylinder (needs a new sleeve), piston, crankshaft with connecting rod (likely will have that rebuilt), replace timing chain and seals.

I spoke to few people and definitely feel like it will be worthwhile fixing this thing.  This thing is in great shape for its age, no rust or anything.  Just need to get it to run again.

 

I'll likely work with Vince at Mr. Crankshaft to get my crankshaft rebuilt.

 

Do you have any recommendations as to where I can find a good used cylinder?  Not sure if it's better to have new sleeve pressed in, or find a used cylinder and have it bored, or just buy a new OEM cylinder?

Also, would I need to have anything done to the top end, such as valve springs, etc?

 

Thanks in advance for your input. I haven't split the case yet but I've attached photos of the cylinder and broken connecting rod.      

[jeepwm69 7,600]

Glad you made it over.

 

A new cylinder will run you about $400.  https://www.rockymountainatvmc.com/oem-schematic/4

 

Then you still have to buy a piston, wrist pin, clips, rings, and gaskets.

 

I'd either buy a used cylinder on ebay and send it to G&H (assuming you don't have a local shop that bores cylinders) or get a "kit" from powersportsnation.

 

How do the valves look?  I always replace the valve stem seals, and grind the valves.  Not hard if you have the little tool.

 

 

[shadetree 5,880]

welcome to the forums. you are deff in the right place for help. depending on how much money you want to spend ?, will determine which way you go. from the looks of that cylinder ^^ . i'd say its toast. start with either a new cylinder ( pricey ! ), or a used one that can be bored over. you will need another crank ( used ) ?, or new rod put back on that crank if the crank is still good ?. new cam chain, all new oil seals, new crank bearings. gaskets. tube of yamabond or hondabond to seal the rocker box..DO NOT USE RTV SEALANT !. new piston kit to match the bored cylinder, g&h can do all of this for the cylinder work. you will need a valve spring compressor tool to put the valves back in the head, a hammer and socket can remove them, but you need the tool to install them back in the head. it would also be a good idea to replace the oil pump chain while you have it apart. inspect the friction disk on the change clutch, inspect the primary clutch weights for wear while also apart. pick up a shindy carb rebuild kit for the carb. replace the fuel lines with new. have any questions, ask away !. 

[Viktor_AZ 1]

Thanks for all the feedback, really appreciate it!  Out of curiosity, I stopped by a local ATV shop and got a quote to have this motor rebuilt.  They quoted me $3,500 which seemed really excessive.  Anyway, I think I'll keep working on it myself and learn a thing or two along the way.   My next step is to split the case - I plan on working on that this weekend.  Will keep ya'll updated and will share photos. 

 

In the meantime, here are some photos of my cylinder head.  I've also included a pic showing the top of piston where the valves were hitting. 

1. Do you think I would need to replace the valves?  Or just  grind the valves? 

2. What do valve stem seals look like?

3. Any other work that would need to be done to the cylinder head?

 

 

 

 

[shadetree 5,880]

3 hours ago, Viktor_AZ said:

Thanks for all the feedback, really appreciate it!  Out of curiosity, I stopped by a local ATV shop and got a quote to have this motor rebuilt.  They quoted me $3,500 which seemed really excessive.  Anyway, I think I'll keep working on it myself and learn a thing or two along the way.   My next step is to split the case - I plan on working on that this weekend.  Will keep ya'll updated and will share photos. 

 

In the meantime, here are some photos of my cylinder head.  I've also included a pic showing the top of piston where the valves were hitting. 

1. Do you think I would need to replace the valves?  Or just  grind the valves? 

2. What do valve stem seals look like?

3. Any other work that would need to be done to the cylinder head?

 

 

 

 

like i said, you will need a valve compression tool to put the valves back in, hammer an socket can remove the valve springs, once these are off ?, you will see the valve guide stem seals on top of the valve guides, under the springs in this case. best to pull the valves, run them in a cordless drill, see if they got bent ?. also check the condition of the valve guides, sometimes when valves get smacked by the piston, the guides break. some degreaser and a small wire brush to clean the carbon out of the head.

[Viktor_AZ 1]

I've finally split the case and I gotta say - this thing is a gift that keeps on giving.   Looks like connecting rod smacked the crankcase and chipped some pieces off 😭 (see pics below) So now, on top of everything, I'll need to see if I can find me a crankcase replacement.  

 

I saw a few used ones on ebay but does anyone know where I may be able to find a clean used or new crankcase for a descent price?   Part # 11200-HM8-000.   

 

I was also leaning toward having my crankshaft rebuilt with a new connecting rod.  However, I'm hesitant to reuse the existing bearings from the original crank.  Does anyone have any recommendations as to where I can get a descent price on a new crankshaft assembly?  Part # 13000-HM8-000.   I've looked at Rocky Mountain ATV and they're asking a little over $400.  Thank in advance! 

  

 

 

[shadetree 5,880]

1 hour ago, Viktor_AZ said:

I've finally split the case and I gotta say - this thing is a gift that keeps on giving.   Looks like connecting rod smacked the crankcase and chipped some pieces off 😭 (see pics below) So now, on top of everything, I'll need to see if I can find me a crankcase replacement.  

 

I saw a few used ones on ebay but does anyone know where I may be able to find a clean used or new crankcase for a descent price?   Part # 11200-HM8-000.   

 

I was also leaning toward having my crankshaft rebuilt with a new connecting rod.  However, I'm hesitant to reuse the existing bearings from the original crank.  Does anyone have any recommendations as to where I can get a descent price on a new crankshaft assembly?  Part # 13000-HM8-000.   I've looked at Rocky Mountain ATV and they're asking a little over $400.  Thank in advance! 

  

 

 

see if power sports nation has a used lower case/cases ?. they might even have a crank ?. you still will need to replace the crank bearings with new regardless.

[Orvis25 108]

Welcome to the forums! @shadetree and @jeepwm69 will steer you the right way for any major engine work you need.
Follow their directions TO THE T!
(learned that the hard way with my engine work).

Hope to see you get her working again.

Worst case, you can always try converting it to take a predator (harbor freight) engine.

I know a lot of people do that when they have blown engines and don't want to spend a lot.

 

[Viktor_AZ 1]

Thanks @Orvis25.  Both @shadetree and @jeepwm69 have been really helpful. 

 

Today, I was inspecting some of the parts and noticed that camshaft had a "chip" (see photo).  Is this normal?  Should I replace it or can it be reused?

 

Wasn't sure if connecting rod smacked and chipped it...  However, I've looked at a few used ones on Ebay and some seemed to have the same chip.  Just wanted to double-check with ya'll. 

[Orvis25 108]

2 minutes ago, Viktor_AZ said:

Thanks @Orvis25.  Both @shadetree and @jeepwm69 have been really helpful. 

 

Today, I was inspecting some of the parts and noticed that camshaft had a "chip" (see photo).  Is this normal?  Should I replace it or can it be reused?

 

Wasn't sure if connecting rod smacked and chipped it...  However, I've looked at a few used ones on Ebay and some seemed to have the same chip.  Just wanted to double-check with ya'll. 

Personally, as long as the part of the lobes that come in contact with the valve lifters are smooth and not damaged, id say its fine. 
I don't own a Trx250, so just check that it (the chipped part) does not directly rub on anything, and if not, id leave it and re-use it if the rest is fine. 

[shadetree 5,880]

5 hours ago, Viktor_AZ said:

Thanks @Orvis25.  Both @shadetree and @jeepwm69 have been really helpful. 

 

Today, I was inspecting some of the parts and noticed that camshaft had a "chip" (see photo).  Is this normal?  Should I replace it or can it be reused?

 

Wasn't sure if connecting rod smacked and chipped it...  However, I've looked at a few used ones on Ebay and some seemed to have the same chip.  Just wanted to double-check with ya'll. 

as long as it does not come in contact with the rocker faces at all ?, simply smooth it down best you can, re-use it. if the lobes are rough ?, then its best to replace it with used or new cam. BE SURE TO REPLACE CAM CHAIN AS WELL !. i use nothing but D.I.D. cam chains, or oem from honda..which by the way..honda does in fact use D.I.D. cam chains in new atvs !. by now you have guessed this project is adding up fast in cost ?, TRUST ME..MOST OF US HAVE BEEN THERE, DONE THAT ?, AND STILL GO TROUGH IT ALL THE TIME !. don't sweat it..once its all back to running ?, pat yourself on the back..have a cold one..enjoy your work !.