Got to test out the 250r with 11 tooth sprocket in front

[sunnyday]

Finally got this 85 - 250r atc back together and running properly. Was having a terrible time with the carb overflowing and finally figured out the floats needed adjusting.

anyways...this had a 14 tooth front sprocket , and it really was to fast for my needs...with that 14 tooth sprocket the powerband was noticebale in every gear. When I nailed it in any gear you could feel the powerband kick in.,..

got the 11 tooth sprocket , and the changes are astronomical. As 1 poster said, it will feel like youve lost 6th gear , and thats about right. Also, the powerband is largely diminshed..its still slightly noticeable from 1`-3 rd gear..but from 4-6th gear, its basically gone.

Definitely notice a power increase ...but im not sure if 11 tooth upfront is where I will stay....looks like some people suggestions to go to a 12 tooth upfront woulda been the best of both worlds...so I may do that. I think the good thing about the power it now has, is it should allow it to climb pretty steep hills, without the need to hit those hills at a high rate of speed...1st and 2nd gear almost feel as though they have the power of a 4 stroker engine now.


On another note, im curious how many riders dont use the clutch on their 250r and shift without it ? It just seems natural on the 250r atc to not really need the hand clutch to often when shifting up thru the gears.

[sunnyday]

I wonder if there is any info available concerning these 250r atcs , as far as stock engine setup and top speed per different sized front sprocket.

in other words..

top speed for 11 tooth , 12 tooth, 13 tooth, 14 tooth, etc...with everything else being stock.

It feels as though I have lost about 20 mph off top end by going to the 11 tooth front sprocket...ecspecially since the powerband has diminished in the top 3 gears.

[atctim]

With having a smaller front sprocket (shorter gears) - your "powerband" should be more noticeable, not less. Not sure where you are coming from???????????????????????????

[HuffieVA]

http://www.ljsoftware.com/DS/GearSpeedCalculator.html

Here you go, keep in mind this doesn't account for any wheel spin, clutch slippage etc...

Like Tim said above, your observation doesn't quite make sense, are you short shifting and running in to high of a gear?

[sunnyday]

With having a smaller front sprocket (shorter gears) - your "powerband" should be more noticeable, not less. Not sure where you are coming from???????????????????????????

not what im experiencing...

dont get me wrong...the gears get up to speed quicker now, with a loss of total top end speed...but that actuall powerband that I felt with the 14 tooth sprocket has diminsihed greatly...

in other words..before with the 14 th sprocket...3 rd- 6th gear had a incredible punch when i nailed the throttle....and you can audibly hear it when it kicked in...now that punch is missing....

before it was like it had a 3rd gear and then a 3-1/2 gear { when you nailed the throttle} and it did this thru all gears... and you could feel it kick in...now 3-6 gears are just there....and that incredible speed band has gone on the last 3 gears. ......


which is fine..im not complaining, just giving my experiences.

[sunnyday]

http://www.ljsoftware.com/DS/GearSpeedCalculator.html

Here you go, keep in mind this doesn't account for any wheel spin, clutch slippage etc...

Like Tim said above, your observation doesn't quite make sense, are you short shifting and running in to high of a gear?

thanks for the chart...

There was another poster on here named tim, who told me it would perform as though it was only a 5 speed...and he nailed that correctly....

along with the incredible loss of the powerband.....

I guess the best way to explain it, would be to compare it to a 4 stroker that had powerstroke that wasnt working properly :}

with the 14 th sprocket...when i nailed it in all gears , the speed was so fast coming, that it felt like it wanted to do a wheelie thru all the gears...

now that is mostly gone...so i guess what happens is this...

the incredible speed that kicks in with the powerband, with the 14th sprocket may not be " power" but more of a intense and immediate boost of speed, that gives the imitation of power...

and now, the 11th sprocket has lost that imitation power boost that was noticed due to the immediate speed kicking in, and replaced that with more of a real power...but that power isnt great enough to make it feel like the front end wants to come up in all gears.

[Mosh]

.


On another note, im curious how many riders dont use the clutch on their 250r and shift without it ? It just seems natural on the 250r atc to not really need the hand clutch to often when shifting up thru the gears.

As I said last week. 85% of the 250R engine (including) transmission gears are DISCONTINUED.
Do a search on here about shifting without the clutch.
It does ruin the trans eventually.
I agree the 12 tooth would have been better..deja vu;)

[sunnyday]

As I said last week. 85% of the 250R engine (including) transmission gears are DISCONTINUED.
Do a search on here about shifting without the clutch.
It does ruin the trans eventually.
I agree the 12 tooth would have been better..deja vu;)

its no big deal to replace the sprocklet with a 12 toother...and they are only about $9....and I may do that ..

so shifitng without the hand clutch, does ruin the gears..even if the shifting is done at the proper moment ?

[sunnyday]

any of you guys running a 14 tooth or higher front sprocket ? ..or is 14 tooth the highest it should go on the front ?

[sunnyday]

actually, i just though of a great comparison..

this 85 with the 11 th sprocket, kinda feels like it runs/performs like a earlier air cooled 250r...in stock formatt

[ATC-Eric]

Yes, shifting without the clutch will eventually ruin something in the tranny. I had to learn the hard way.

[RIDE-RED 250r]

I was running 12/39 gearing on my stock cylinder with a better carb, reeds, exhaust and high compression setup and found that gearing to be quite good all round. I could have used a little more upper midrange-topend puch but the engine was setup more for low end/midrange anyway.

Yes, slam shifting it IS hard on your gears and shift forks. I recently found out they don't make shift forks anymore either. They were still available about a year ago, but now discontinued. Don't abuse your transmission.

What I do when I want to power shift (so to speak) is keep the throttle pinned while administering a quick pull of the clutch and a gear shift. You get a quick burst of RPM as you shift and instead of the gears and transmission taking the brunt of of the stress, the clutch does instead. Clutches are still readily available.

Tomorrow, I will be helping my cousin re-assemble his '87 TRX for about the 3rd time due to transmission troubles. That's how I know the shift forks are NLA....

[falloutboy]

I guess I don't get it. You want a nice, mild, low end, smooth power curve, and don't really want the bike to be fast.

You should have just bought a 4 stroke :wondering

[350XJEDI]

:wondering a slow 250r ? get a us90 :eek::confused::crazy::beer:beer:cry: WHY OH WHY :cool:

[TimSr]

On another note, im curious how many riders dont use the clutch on their 250r and shift without it ? It just seems natural on the 250r atc to not really need the hand clutch to often when shifting up thru the gears.


Whats a clutch? Is that the lever I only pull when coming to a coming to a complete stop, or starting from one? True, l only had my 86 TRX250R for like 4 years, but after 22 years of abuse on my longest used 85 TriZ gearbox, Im still waiting for that catastrophic gearbox failure. My 86 gearbox has only been abused for like 10 years though so it might come at any time. Maybe my secret is that Dollar General 10W40 oil I run in them!

I think the debate over powerband here revolves around a misuse of the term. Powerband is the RPM range at which your motor delivers maximum power, and has nothing to do with gearing. The only thing that will change with gearing is the speed you are going in a given gear when you reach that RPM level. If you change gearing to that extent and shift the entire gearbox range down by one gear, roughy speaking, gears 2, 3, 4, 5, and 6 should feel nearly indistinguishable from what gears 1, 2, 3, 4, and 5 used to be.

[Mosh]

Whats a clutch? Is that the lever I only pull when coming to a coming to a complete stop, or starting from one? True, l only had my 86 TRX250R for like 4 years, but after 22 years of abuse on my longest used 85 TriZ gearbox, Im still waiting for that catastrophic gearbox failure. My 86 gearbox has only been abused for like 10 years though so it might come at any time. Maybe my secret is that Dollar General 10W40 oil I run in them!

.
Tim, I have split I dont know how many engines over the years. Hondas have weak gears compared to all others.
Out of all The Z engines I have split, I have almost never seen any weak or damaged gears, including Banshee's. Yamaha's just dont have the problems with the trannies like Honda's suffer from abuse. Either way, Z trannies are a dime a dozen and almost never fail..However stated for a 3rd time, Honda 250R trannies are worth their weight in gold and getting harder to get. Just last Spring I did Kintores old 250R motor that only saw 5 years of MX abuse. 2nd and 3rd gears were gone.
Just ask Brian..Took him 3 months to find a trans cluster for His R, and that was damaged from clutchless shifting. All beit from 20 years of MX abuse, but still it met its demise.

[swampthang]

What's the advantage of shifting without using the clutch? I know when you pull in the clutch your taking away from your forward momentum but its only for a fraction of a second. Seems like more trouble then good when it comes to reliability. So is there any advantage?

[4x4van]

Shifting without the clutch is like playing russian roulette. You may get away with it for a long time, but at any time, "BANG". And as RIDE-RED 250R said; trans parts are getting harder and harder to find. Is it worth the chance?

I think what you're feeling (regarding the "powerband") is the fact that with the very high gearing (14t), the RPMs had to increase a bit before the engine's powerband could actually pull those top gears, so you would feel the "hit" when it reached that point. With the extremely low gearing (11t), the engine can pull those same gears easier, so it is already "in" the powerband, so to speak; there is no "hit" because it's already there. I think you would be feeling the same thing with the 12, or even the stock 13. The 14 was so high that it was effectively robbing the bike of it's low end, especially in higher gears.

[TimSr]

What's the advantage of shifting without using the clutch? I know when you pull in the clutch your taking away from your forward momentum but its only for a fraction of a second. Seems like more trouble then good when it comes to reliability. So is there any advantage?

The advantage is strictly in forearm fatigue. It is not some trick to make you faster.

I accept Mosh's explanation of Honda trannies being less durable as fact.

Fact is, the pupose of the clutch is to momentarily equalize the speed of two moving assmbles so the they can me meshed together, and if you can shift precisely every time, without the clutch, will be no additional wear or stress. The problem comes in due to the fact that most of us are human, and none of us can shift perfectly every time, so maybe you should use your clutch on your Honda, but if you halfway know how to shift with yout Yamaha, its strictly an option.

I'm rembering a couple years ago now that my cable end broke at Summit Indoors, and I raced two motos without even having benfit of the clutch for the start, and had to half throttle before dumping into gear, but that I don't recommend. :D

[atc300r]

. They get enough stress under normal riding.Not to mention racing.And shifting with out the clutch Like said above one mistake and you splitting the cases to put in a new set. It would take much to break or bend a shift fork.I have 4 250rs 1 liquid three air.and the last thing I want to do is split the cases.I know and have done the shift with out the clutch thing where you let of and blip the throttle and it slides right in.Even done it on a manual truck and cars.But I out grew that quickly.To me its like people that dont use there signal light when they turn .Its right there at your finger tips.Use it.Also I read an article from Mike Coe he was a Honda ATC 250r racer from back in the day .And he said that he ran a 14 tooth front spocket .He said that the smaller the front sprocket the harder it was for the chain to come around on it.Kinda like a binding thing .