Whats the best Rpm to shift? And sprocket question

[kidflyr]

Dynojet uses different numbers from keihin, who made the stock carb on the KLR250. Here's a comparison chart near the bottom of the FAQS: http://www.jetsrus.com/FAQs/FAQ_miku...ihin_sizes.htm
I got my jets from jetsrus.com. It was much cheaper than the Dynojet kits, cost me about $7 or $8 for jets but I couldn't resist the other goodies like stainless float bowl screws. I got a 38 pilot jet and 125 main jet, running stock exhaust, uni bulk foam filter and no snorkel. You might consider also getting a 40 pilot and 128 jet to evaluate what runs best once you get that aftermarket exhaust. I picked up a #4 stainless washer from the hardware store for $0.09 to accomplish the same effect as what the Dynojet kit has you do with the needle, but have yet to install it because I have been riding


EDIT: from the chart on the jets'r'us FAQS, a Dynojet 118 main jet is equivalent to a keihin 125 main jet, and a Dynojet 120 main jet is equivalent to a keihin 128 main jet.

[davidbynum]

Originally Posted by kidflyr

Dynojet uses different numbers from keihin, who made the stock carb on the KLR250. Here's a comparison chart near the bottom of the FAQS: http://www.jetsrus.com/FAQs/FAQ_miku...ihin_sizes.htm
I got my jets from jetsrus.com. It was much cheaper than the Dynojet kits, cost me about $7 or $8 for jets but I couldn't resist the other goodies like stainless float bowl screws. I got a 38 pilot jet and 125 main jet, running stock exhaust, uni bulk foam filter and no snorkel. You might consider also getting a 40 pilot and 128 jet to evaluate what runs best once you get that aftermarket exhaust. I picked up a #4 stainless washer from the hardware store for $0.09 to accomplish the same effect as what the Dynojet kit has you do with the needle, but have yet to install it because I have been riding


EDIT: from the chart on the jets'r'us FAQS, a Dynojet 118 main jet is equivalent to a keihin 125 main jet, and a Dynojet 120 main jet is equivalent to a keihin 128 main jet.

Okay cool thanks that will save a good bit of $ vs the dynojet kit, and I think I will go ahead and get a couple different main and pilots to experiment around a little. The dj kit instruction online state that you need to drill the slide do you know what bit size the kit uses?
Thank you

[davidbynum]

Also, a little off topic but do any of you use the ricochet skid plate? I just ordered one this morning. if anyone does have one how is it? how was isntall? i'm hoping it's just unbolt the stock one and bolt the ricochet on... from the pics it looks like it will be WAY better than the flimsey stock one.

[TownsendsFJR1300]

Originally Posted by davidbynum

Also, a little off topic but do any of you use the ricochet skid plate? I just ordered one this morning. if anyone does have one how is it? how was isntall? i'm hoping it's just unbolt the stock one and bolt the ricochet on... from the pics it looks like it will be WAY better than the flimsey stock one.

It is very heavy duty.

You will find the oil drain plug hole off some and may want to oblong the hole to make oil changes easier. It DOES REFLECT ENGINE NOISE back to the rider (at least on the street, BIG TIME). I thought I had a major bearing blowing out. I ended up returning the plate as most of my riding was on the street and the noise (at speed) was unbearable for me...

The mounting (as I re-call, its been about 3 years) is not hard to do, and uses its own hardware.

[kidflyr]

Originally Posted by TownsendsFJR1300

It DOES REFLECT ENGINE NOISE back to the rider (at least on the street, BIG TIME).

You could mask off the holes and exterior of the new plate then give the engine side several thick coats of rubber car body under liner. It may attenuate some of the sound if the engine vibration is causing the plate to vibrate and reproduce engine noise, though I don't expect it to absorb much noise, I would expect it to be most effective at absorbing high frequency sounds and less effective against lower frequencies.

I had a positive experience with a product called QuietCar which attenuates vibration. I used it to abate road & exhaust noise in my S2000 (catalytic converter was by passenger's leg along the transmission tunnel before I moved it to my closet). While it would be effective if vibration is the problem, it's too pricey to evaluate experiment with for a skid plate IMO; rubber under coating is much more wallet-friendly for casual experimentation.

[Enumclaw]

Originally Posted by davidbynum

Also, a little off topic but do any of you use the ricochet skid plate? I just ordered one this morning. if anyone does have one how is it? how was isntall? i'm hoping it's just unbolt the stock one and bolt the ricochet on... from the pics it looks like it will be WAY better than the flimsey stock one.

I have one also, it's very solid. Mounting is a breeze. I've never noticed any excessive engine noise after installation, but then again I wear earplugs....

[davidbynum]

Originally Posted by davidbynum

Okay cool thanks that will save a good bit of $ vs the dynojet kit, and I think I will go ahead and get a couple different main and pilots to experiment around a little. The dj kit instruction online state that you need to drill the slide do you know what bit size the kit uses?
Thank you

does anyone know about the slide drill bit size?

[kidflyr]

7/64. Inch. It should be in any drill index, and you likely already have a bit that size. I've been curious about drilling the slide, but have stuck with shimming the carburetor needle with a #4 washer and a thorough polishing as far as my slide is concerned. I would like to know what effect it has on your mpg's. I was getting 55-59 before I put the 16 tooth sprocket up front just recently.

[TownsendsFJR1300]

Originally Posted by kidflyr

7/64. Inch. It should be in any drill index, and you likely already have a bit that size. I've been curious about drilling the slide, but have stuck with shimming the carburetor needle with a #4 washer and a thorough polishing as far as my slide is concerned. I would like to know what effect it has on your mpg's. I was getting 55-59 before I put the 16 tooth sprocket up front just recently.

With the only carb mod on my last 2005 250 being opening the idle air screw on the bottom (just ahead of the float bowl), my stock engine carb was getting about 70 MPG around town... It ran fine for me.

Doing the carb mods will give you more get up and go but will likely hurt your mileage....

[davidbynum]

Originally Posted by TownsendsFJR1300

With the only carb mod on my last 2005 250 being opening the idle air screw on the bottom (just ahead of the float bowl), my stock engine carb was getting about 70 MPG around town... It ran fine for me.

Doing the carb mods will give you more get up and go but will likely hurt your mileage....

How badly do you think it will drop if i do everything the dynojet kit does?

I wont be too bothered if its only 5-10mpg

Originally Posted by kidflyr

7/64. Inch. It should be in any drill index, and you likely already have a bit that size. I've been curious about drilling the slide, but have stuck with shimming the carburetor needle with a #4 washer and a thorough polishing as far as my slide is concerned. I would like to know what effect it has on your mpg's. I was getting 55-59 before I put the 16 tooth sprocket up front just recently.

Okay cool i do have that size, i'll post on here with results when i get it done.

[davidbynum]

Back to sprockets, i originally wanted to gear down for hills but i guess it was just a matter of getting used to the bike.

I actually want to go a couple teeth smaller on the rear now to make first gear a little less useless and get a little more top speed, will that be much of a difference in top speed?

Im thinking it shouldn't hurt the oomph of the bike if i do it the along with the big gun exhaust system/jet kit/air box mod and hi flo air filter does anyone have any thought on this?

[kidflyr]

I put a 16 tooth sprocket up front and rode from Arcata to Yreka yesterday with my backpacking stuff on me with no problems I even got up to 75mph (gps) going by Ashland though I did have to downshift to 5th for a couple of hills along the way. I have been going WOT most of yesterday and today, dropping my mpg's a bit but I haven't been filling up to a consistent level to calculate tank to tank. I'm riding Medford to Lassen or Lava Beds today :-D

opening up the airbox helps lots btw if you haven't already!

[davidbynum]

Originally Posted by kidflyr

I put a 16 tooth sprocket up front and rode from Arcata to Yreka yesterday with my backpacking stuff on me with no problems I even got up to 75mph (gps) going by Ashland though I did have to downshift to 5th for a couple of hills along the way. I have been going WOT most of yesterday and today, dropping my mpg's a bit but I haven't been filling up to a consistent level to calculate tank to tank. I'm riding Medford to Lassen or Lava Beds today :-D

opening up the airbox helps lots btw if you haven't already!

Will dropping 2 or 3 in the rear be a decent change as far as gaining top speed?

Im lagging it on doing all my mods, i want to do the airbox when i take off the emissions stuff and also put a uni in there when i do the airbox. I got all my jets and just need to wait a week or two to buy the big gun and sprockets/chain so hopefully i'll have all that done this month.

That sounds like a fun couple days, i think my longest ride so far was around 75 miles each way, does the bike get hot riding around 60-65mph for longer distances or is it pretty good at keeping cool?

Have fun and ride safe

[kidflyr]

The bike is too good at keeping cool. I have a piece of cardboard blocking the left side radiator and the temperature guage stays left of center up to about 85F. Hasn't passed the three quarters mark up to 108F ambient. I need a thermo-Bob badly!

[davidbynum]

Originally Posted by kidflyr

The bike is too good at keeping cool. I have a piece of cardboard blocking the left side radiator and the temperature guage stays left of center up to about 85F. Hasn't passed the three quarters mark up to 108F ambient. I need a thermo-Bob badly!

What does a thermo-bob do?
Ive only had mine go past the half mark and had the fan come on once while going up a steep dirt hill in low gear so far.

On a side note im definitely gearing mine up, 1st is just too useless, im constantly finding myself approaching a light thats about to turn green and have to make the choice of lugging it in 2nd or letting out the clutch in 1st at like 6k rpms and i hate both options.

[kidflyr]

A Thermo-Bob is a thermostat in an external housing, allowing the addition of a mixing circuit (part of the kit), made/sold by Watt-Man, a user on the forum. With the Thermo-Bob installed, coolant doesn't make the trip through both radiators until it gets up to operating temperature, and coolant returning to the engine meets and mixes with some hot coolant from the mixing circuit. The result is a more consistent cylinder temperature, kept closer to ideal operating temperature than the OEM cooling system can maintain. Watt-Man's site is watt-man.com, and the information & articles page is handy too: http://www.watt-man.com/Information__Articles.html

As for gearing:

Originally Posted by kidflyr

I have a 16(up one from stock) front and 44(stock size) rear sprocket, giving me a 2.75:1 reduction (divide rear sprocket teeth by # of front sprocket teeth for the ratio), and I feel it's about as much as the bike can muster in 6th gear.

Here's a handful of ratios laid out, grouped by front sprocket tooth count and ordered from gear ratios favoring top speed to those favoring acceleration:

Top Speed
40/15=2.6666
41/15=2.7333
42/15=2.8000
43/15=2.8666
44/15=2.9300 Stock/OEM gearing
45/15=3.0000
46/15=3.0666
Acceleration


Top speed
40/16=2.5000
41/16=2.5625
42/16=2.6250
43/16=2.6875
44/16=2.7500<=Gearing I'm running and pleased with.
45/16=2.8100
46/16=2.8750
Acceleration

With a 16 tooth front and 44 tooth rear I'm at about 6800-6900 rpm at 70 mph gauge indicated (65ish by gps). top speed is about 85ish indicated, 76.8 mph according to gps, at 7900rpm, just a hair shy of peak torque output which is 8000rpm according to Kawasaki.

[TravlinLeoJ]

Originally Posted by kidflyr

...I did have to downshift to 5th for a couple of hills along the way.

Where are you guys getting 6-speed KLR's?!!

Did I miss something, or is this a typo?

[kidflyr]

Originally Posted by TravlinLeoJ

Where are you guys getting 6-speed KLR's?!!

Did I miss something, or is this a typo?

The KLR250 is a six speed.

[TravlinLeoJ]

Originally Posted by kidflyr

The KLR250 is a six speed.

Ah HA!!

Thanks!

[davidbynum]

Will i need to do anything to my chain if i go down 2 or 3 teeth on the rear sprocket?