Fasted 250 Big Red needs tall gearing.

[Mickey Dunlap]

I admit I have no idea of what gearing I need to gear my 250 es Big Red as tall as I can. What rear end gears do I need and what Engine gears do I need and who has them for sale?

Project "Sleeper" is in the making!

[onformula1]

I don't know what that engine will actually pull, but I use these guys-

http://sprocketspecialists.com/sprocket-specialists-parts-catalog-home/

Excellent product, tons of options, steel or aluminum & if you check out their website they obviously support 3 wheelers, so many places don't!

They have counter shafts sprocket from- 10-15 in one tooth increments.

They have rear sprockets from- 34-74 in one tooth increments.

I don't think that trike will pull 15/34 though....unless Mickey Dunlap built it!...LOL

[Flyingw]

By taller gears, can I assume that you want higher gearing for more top end?

[Mickey Dunlap]

Yes I need gears not sprockets with the shaft drive. I didn't pay attention to what gears and what rear end diffs they used.

[onformula1]

By taller gears, can I assume that you want higher gearing for more top end?

I assumed that's what he meant-
Old school hot rod guys would say taller gears for higher gearing & short gears for lower gearing.

[Louis Mielke]

I'm pretty sure he's talking about a bigred 250es, shaft drive, and thus he's looking for rear end gears. I think the trx300 rear end swaps and is taller?

[onformula1]

Missed that, sorry I can't help. Never heard of different gears being made by anyone. Custom built?

How about some 36" tires?

[Flyingw]

What I can offer is this, the SX tranny is geared higher. Each gear is one tooth smaller. The same for the rear end. The SX has a unique gear set whereas the ES and TRX all use the larger ring gear. I once tried to stick an SX gear set in to an ES case. It was then I realized the ES main shaft has a very slight machining difference and when I tightened down the cases, the main shaft wouldn't turn. I then tried an ES gear set in SX cases and the gear set just didn't stack up right so I ended up putting an ES motor in my SX. If you want taller gearing in your ES, put an SX motor and differential in your BR.

[NeverLift]

http://www.yukongear.com

I've never had it done but one of my instructors at MMI said these guys built him custom gears for his CR250. Give them a call i'm sure they can build you whatever you need.

[Mickey Dunlap]

I'll buy a SX motor then to see what I can do, but I already have a extra ES motor. I'll get the gears for the 300 rear end and maybe that will be enough gearing so I don't hit the rev limiter so quick. I remember our SX at Powroll hit the limiter too quick, so I know it's going to be a problem, unless the ES doesn't have one. Anyone hit the rev limiter on their Big Reds?

[Mickey Dunlap]

209607So this is all I need out of the TRX 300?

[Flyingw]

Mickey, I have an 86 ES diff already rebuilt if you want to go that route. I tooled up to rebuild differentials so it is completely rebuilt and not just the ring gear bearings and seals. 325.00 shipped. If not, keep in mind the ring and pinion gears are match ground when they were manufactured.

[Mickey Dunlap]

Mickey, I have an 86 ES diff already rebuilt if you want to go that route. I tooled up to rebuild differentials so it is completely rebuilt and not just the ring gear bearings and seals. 325.00 shipped. If not, keep in mind the ring and pinion gears are match ground when they were manufactured.

I think I'm getting a 85, is there a diff with the diffs? lol I have never been in one so I have no idea what goes bad, but I want it rebuilt right but with taller gears.

[Flyingw]

In 86, Honda made a casting change in that the sealing lip on the axle tube was lengthened. The corresponding sealing surface in the diff was deepened to accommodate the extending sealing lip on the axle tube. Their attempt failed!!! Water intrusion was still a problem using their OEM configuration utilizing an oring for the seal. Throw away the oring and seal each joint with silicone. The 86/87 diffs can be used on any year swingarm but you can't use an 85 diff on an 86/87 without doing some grinding on the axle tubes. The one I have is an 86/87 diff.

The main point of failure in the diff is the needle bearing on the end of the pinion shaft. When the needle bearings fails, the ring and pinion gears destroy themselves in short order. Special tools are required to get the pinion shaft out of the case and other off the shelf tools are needed to get the needle bearings out. I have all the tools to rebuild the diffs. If you want to see what's involved with the diff and see the inside of the diff, checkout my tutorial on rebuilding the diff.

http://www.3wheelerworld.com/showthread.php/164483-ATC-250SX-and-250ES-Differential-Rebuild-Tutorial?p=1282554#post1282554

[Mickey Dunlap]

OK I can handle all that our Brute Force front diff is like that. My big question is have you ever geared one up?

[Flyingw]

I have taken the gear set out of a 300 diff and stuck it in an ES case but that's not really gearing up so to speak. I've put SX gears in ES cases too.

[Mickey Dunlap]

I have taken the gear set out of a 300 diff and stuck it in an ES case but that's not really gearing up so to speak. I've put SX gears in ES cases too.


Why didn't it gear it up. I looked for how many teeth each had and I couldn't fine that on Bike Bandit. So the SX gears will go into the RS cases, so it is a taller gear box on every gear?

[Chopsaw]

I have a 85 sx engine in a 85 es with the es rear end . Pulls good thru all the gears , plenty of top end for me .

[Flyingw]

Here's the two gears side by side. Remember, the TRX and ES use the same ring gear and the SX stands alone one tooth smaller
..

[Mickey Dunlap]

Does anyone have a plane and simple answer to what parts, engine or what ever I need to gear this ES needs.

[fabiodriven]

You're baffling everyone man. Convey yourself in a manner in which others can understand.

[jeswinehart]

Well for what it's worth I put a 85
Sx differential in my 85 es for the sole purpose of more top speed.
Not a big jump gained but defiantly noticeable.

John

[fabiodriven]

"Fasted 250 Big Red needs tall gearing."

^^^That^^^ doesn't make sense first of all.

I know what "tall gearing" means. It means you want to swap out your 3.73's for 2.73's in your Mustang. You want more top speed, less pulling power. You want taller gears, or higher gears, or lower numerically. Those all mean the same thing. If that's what you want, the SX differential will give you taller gears by (what sounds like) one tooth. The ring gear is smaller in diameter and has one tooth less, so a little more top speed. I believe the transmission gears are different between the SX and ES as well. I'm sure these boys can straighten you out on that as well.


So the SX gears will go into the RS cases, so it is a taller gear box on every gear?

When you write things like this you are going to lose everyone. We don't all speak Mickinese. We speak mostly English and there are other guys that speak other languages, but you and Jesus are the only two speaking your language. You didn't even get the nomenclature of the bike right you're trying to ask for help on. It's an "ES". These guys are all dying to help you, god bless 'em, and you're getting frustrated at them because nobody can tell what the hell it is you're saying. Not their fault. Try it like this;

Hello! I have an 85 Honda Big Red 250ES that I would like the tallest gearing possible on. What are the differences in both the transmission ratios and the final drive ratios between the ES and the SX?

Or some variation of that, depending on what it is you are trying to accomplish. I would venture to guess between the two transmissions and two rear ends there are a couple of different ratios you could potentially end up with. If that example happens to be the very question you intended to ask, by all means feel free to copy it and paste it.

[Flyingw]

Mickey, the simple answer is to gear up an ES, you need an SX transmission and SX differential. Couple those two parts with 25" tires and it will go faster but loose some bottom end torque but probably not much. That's the best answer I can give.

[Mickey Dunlap]

Mickey, the simple answer is to gear up an ES, you need an SX transmission and SX differential. Couple those two parts with 25" tires and it will go faster but loose some bottom end torque but probably not much. That's the best answer I can give.

Thanks but all I need is 450 Fourman gears off the crank and behind the clutch for a 18% gain.

[tripledog]

^^^ If you already have the answer, why ask the question?

[Mickey Dunlap]

^^^ If you already have the answer, why ask the question?

Because I got the answer to my question on Face Book where I was understood without being talked down to.

[big specht]

What are you building? Or what is it going to be for? I would think you could put ride the suspension as it is already ? Not trying to get into the pissing contest just woundering :)

[fabiodriven]

Because I got the answer to my question on Face Book where I was understood without being talked down to.

Yep, they certainly speak your language there!

[Mickey Dunlap]

What are you building? Or what is it going to be for? I would think you could put ride the suspension as it is already ? Not trying to get into the pissing contest just woundering :)


It's for my sleeper Big Bed project. I know with as big of a motor as I'm going with it's going to hit the re-limiter quick, so I need to use the torque and gear it up. I want it to blow any 4 stroke away that I run with out trail riding.;)

[Jmoozy27]

That would make for a cool thread. I would definitely like to see that. Is it expected to have any overheating issue? Possibly an oil cooler installation?

[jeswinehart]

Why don't you just eliminate the rev limiter Mickey ?

[Mickey Dunlap]

That would make for a cool thread. I would definitely like to see that. Is it expected to have any overheating issue? Possibly an oil cooler installation?


I built these back in the 90's when we GNCC raced them in the TRX 300's with no problems but I can't remember if I put my cooler on them or not.

[Mickey Dunlap]

Why don't you just eliminate the rev limiter Mickey ?

I hate electrics and I don't know how. I had a guy doing it in my 250x, 300ex and moved the retard up in the 350x, but he didn't claim the money I paid him and the IRS knocked on his door and he got mad at me for him not paying his taxes.

[Flyingw]

The Rev limiter is programmed in top the EPROM chips that are in the CDI. If somebody had the programmer it would be easy.

[jeswinehart]

Oh. So I am sure the wire terminal ends differ somehow but couldn't a 85es or 85sx be used instead of the 86/87 cdi ?
Neither of those had a rev limiter or at least my 85es and the 85sx I Used To Own Did Not Have it,,,,

[Mickey Dunlap]

Most stock motors won't hit the limiter unless you are going down hill. I just remember the Powroll SX wouldn't rev high enough to use the bigger cam. You banged through the gears so quick it wasn't even fun to ride. And the front end wouldn't stay down. That's why I wanted the Big Red being longer.

[Flyingw]

The CDIs do have rev limiters programmed in to them. Both ES and SX do and as Mickey pointed out, its designed to prevent engine over-speeding with no load on the motor. The 85 ES and SX CDIs had a single round plug. In 86, Honda took the engine kill wires out of that plug and moved them in to a second plug so the 86/87 have a two plug configuration. Honda did that to other models that year the same way.

[jeswinehart]

I am still sticking with no rev limiter on the earlier model es/sx.
There are some postings pertains to this on here somewhere.
If I recall correctly it was only after sx cranks started breaking limiters was added.
KB has some great info on cheap after market cdi's that are universal fits. I will find that tomorrow and copy\paste.

[Flyingw]

Ya I'd like to read that.

[petesatc]

I know how to remove the rev limiter from the CDI if that is the problem???

[jeswinehart]

Reference to a universal cdi
http://www.3wheelerworld.com/showthread.php/144910-1984-200ES-CDI-Replacement-MythBusted/page2?highlight=1984+200es+cdi+replacement%2C+myth busted

Post 5 shows some of the service bulletin.
http://www.3wheelerworld.com/showthread.php/64927-250-SX-won-t-shift?highlight=rev+limiter+on+honda

Not that any of this is probably pertaining to Mickeys needs,,,, Pete how is it done ?

[Mickey Dunlap]

I'm not worried about the crank breaking or anything like that, for one it won't have the big heave clutch hanging of the crank because it will get rid of the auto clutch, it will be a manual clutch. Gets rid of a few pounds off the crank.. This is a sleeper, they won't know what they just go beat by! lol

[TheRealFatShady]

I think you can change the primary gear and the clutch basket gear from a foreman 450. I remember someone had done it while most used 250x/300ex gear swaps to lower their gearing for mud.

[big specht]

No auto clutch? How what other cases fit on it

[yamaha225dr]

Glad you found a way to change the gearing Mickey! I'm not sure who learned that trick on how to change the gearing by swapping out with gears from other quads but the mud boggers back home in Louisiana have been turning Honda 300's into serious machines by doing the gearing reductions. They have them from an 18% to 54%. Those guys did understand that you want to gain top speed instead of lowering it, right? My memory is a little vague right now but I thought using the gears from the Foreman 450 gave an 18% reduction in gearing.

[Mickey Dunlap]

Glad you found a way to change the gearing Mickey! I'm not sure who learned that trick on how to change the gearing by swapping out with gears from other quads but the mud boggers back home in Louisiana have been turning Honda 300's into serious machines by doing the gearing reductions. They have them from an 18% to 54%. Those guys did understand that you want to gain top speed instead of lowering it, right? My memory is a little vague right now but I thought using the gears from the Foreman 450 gave an 18% reduction in gearing.


That's what I was thinking because this was a mud guy. It's kind of funny, I got on the internet to help people because I read so much bad info. So now I'm on the other end of it trying to get good info, and how many different way have I been told how to do it now, six? lol

The good news is I rode my first Big Red of my own today! I think that's also the first three wheeler I have rode in about 27 years. lol

[yamaha225dr]

Cool deal,Mickey! We all need help from time to time. I done some googling and found that using the gears from an 85 Model 250 Big Red in a Foreman 450 will yield an 18% gears reduction. I am betting that is what the information you received was for. I didn't know Honda changed some stuff on the 86 Big Red, the guys said the last two years of them would not work.

[big specht]

That's what I was thinking because this was a mud guy. It's kind of funny, I got on the internet to help people because I read so much bad info. So now I'm on the other end of it trying to get good info, and how many different way have I been told how to do it now, six? lol

The good news is I rode my first Big Red of my own today! I think that's also the first three wheeler I have rode in about 27 years. lol

Except the flat track 70's

[Mickey Dunlap]

Except the flat track 70's

I'm sorry, you are right, but I was so sick I don't remember that much about riding them. Plus I was only on two wheels most of the time if you know what I mean, and that was only at half throttle! lol

[big specht]

I'm sorry, you are right, but I was so sick I don't remember that much about riding them. Plus I was only on two wheels most of the time if you know what I mean, and that was only at half throttle! lol

Lol yea they are differant to ride