Big Red motor question

[oldtoys72]

Ok guys here's the deal..... I just picked up an 85 BR for 20 bucks! Thing is it needs a new crank shaft. Im wondering where/if i can get one? are the 250es and 250sx motors interchangable in their frames? Also the guy i bought it from said that there are two different size crank options.... is their truth to this? basically Im trying to figure out here what my options are as far as how to get this thing operational again! fill me in on what my options are please....

[TheRealFatShady]

I believe the SX and ES engine swaps 100% within the frames. The differential gearing is different and supposedly some parts of the gears are.

Another option is using a TRX300 crank and rod (2wd or 4wd I believe, 1988-2000) and cylinder/piston. They have more options such as big bore kits. The stock Big Red and SX pistons won't work with the TRX300 crank, the stroke is slightly longer.

I'm about to put a TRX engine in my Big Red, so I'd be able to get you a crank/any other parts if you need them pretty cheap.

[oldtoys72]

parts as in parts from your original 250es motor?

[Dirtcrasher]

Why would a big red need a crank?? They bathe in oil and are bulletproof!! IMHO................

Whats bad, the rod?? Did it run low on oil??

[oldtoys72]

The crank shaft is snapped, The guy said that his son ran into the back of the BR with a four wheeler and it snapped the crank from the force I guess. Said the BR kept running then once he shut it down that was it.

[oldtoys72]

the motor is all torn apart and everything looks great other than the broken crank shaft.

[TheRealFatShady]

Never heard of that happening unless you literally took the crank out and dropped it off a cliff or out of an airplane? Is the frame/rear end/jug/side cases all good still?

But yes I have a 250es engine I'm not going to use, will use whatever parts I need for my SX to fix the noise it makes, and I need the angle drive from it.

[oldtoys72]

Ya everything is good i believe, weird right? I will snap a few pics tomorrow after work for you guys to see exactlly what I am talking about. TheRealFatShady; PM me about the motor and maybe we can figure something out huh

[Dirtcrasher]

I have a 250ES bottom end, you can have the crank for 15$ and shipping......

[oldtoys72]

DC; PM me how much to ship to 56701 and how to pay you please

[Dirtcrasher]

Let me see which box it fits in.... I'm sure it won't be anymore than 30$ shipped Priority Mail - ATCST@Verizon.net is my Paypal also......

Email me at the link below if you don't hear from me, little by little this ES is going bye bye :lol:

Need anything else? I need a set of 350X triples, got any??

[oldtoys72]

Sounds good, just let me know. Doesn't have to be priority, I can't get to it for a bit anyways.

[Dirtcrasher]

Yeah, your gonna have to tear it all down, a complete VESRAH gasket kit works great.

Very odd that an impact broke the crank, it wasn't rolling or "driven" it was freewheeling so I don't see how it could break??

But, if it's broke, it's broke! Just remind me like I asked......

DO NOT TAKE OUT THE 3 BOLTS FOR THE DRIVESHAFT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Slide the boot back, the motor forwards and do as the book says......

[oldtoys72]

The motor was already taken apart when I got it. Its gonna be a lot of fun trying to piece it all back together

[Dirtcrasher]

ME = Confused.......

I thought all was fine and dandy until someone smashed into your Big Red?? The next start you determined it to have a bad crank. I'm still on the fence as to how a sudden shock could do that.

I'll say this, I can do it, but the 250ES and SX have more thrust washers, one way clutches, oil lines etc than anything I've ever seen. I'd take it slow and easy while referring to the Honda Shop Service Manual as I went...............

[oldtoys72]

I bought the big red on saturday, the previous owner had already taken the motor apart, ordered wrong crank and then just left it sit in his shop for 7yrs. He told me that he was riding it and a family member of his ran into the back of it with a quad causing the crank to break.Now I have a motor in a box that needs a new crank and reassembly.

[will_15942]

i have a good complete bottom end $50.00 plus shiping

[ailll1]

DO NOT TAKE OUT THE 3 BOLTS FOR THE DRIVESHAFT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Im curious, why not?
Tried to remove them last time I removed my swingarm, but I guess it's a good thing they wouldnt come out without stripping.

[TheRealFatShady]

Im curious, why not?
Tried to remove them last time I removed my swingarm, but I guess it's a good thing they wouldnt come out without stripping.

Thrust washer that gets lost and slowly destroys first gear. Need to split cases to get it back out or VERY carefully fish it out without splitting the cases. Dirtcrasher told me all about it, I'm hoping to get some pictures up if I ever get to working on mine.

[ailll1]

Thrust washer that gets lost and slowly destroys first gear. Need to split cases to get it back out or VERY carefully fish it out without splitting the cases. Dirtcrasher told me all about it, I'm hoping to get some pictures up if I ever get to working on mine.

Alright, I'll wait for pics
I love pics :P

[oldtoys72]

ok so here are a couple of pics that i snapped with the cell phone, just got home after a 14 hour day so didnt want to try to find the camera, just wanted to sit down in the recliner!

[muddog]

that looks like more happened than just a hit from behind

[pirate122]

I do beleive the previous owner was probably triyng to remove the clutch whit a impact drive by holding the piston rod,and did'nt realise the nut is a left hand tread and broke the crank,because if the motor is idling the clutch wont be engage and it will only spin free on the crankshaft.

[pirate122]

I sugest you to buy anoter bottom end because it is gonna cost you a arm to rebuild this one, make sure you get parts from same year, 250 es motor and sx motor are 100% same engine,but 1986 are different crankshaft,and gears,oil pump gears etc. if a good member from here offer you a complete bottom end for a good price well take it you will save a lot's of monney and headik.