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Discussion Starter #1
Yup, Last year I bought a new to me exhaust, and with it the guy through in the DynoJet kit. It was new and never opened. Well, the plastic box was opened, but all the little bags were still sealed. Anyway, the EBayer didn't like how loud the pipe was so never installed the kit. Cool.
So I received everything,excites like a child at Christmas. I install it all on the bike. Everything is wonderful to me, I didn't know better then,
Fast Forward One year.

Covid-19 FREAKEN LOCK DOWN!??!!

So I began searching this forum and reading etc etc, blah blah blah.

Then I see a link to this SUPER DOO DUDE!-------CLICK------HUMMM--+++

Things start adding up now. I like the way this guy thinks. Then there it was!!! A write up on his page for Carb mods. The right way. OPPS, Then I got my old DJ box out and did a number search. Its for 2nd Gen. Not Gen 1.

Git to diggen into the box, because I can't remember what size jet I used. All this sitting around and thinking "Covid" stuff got me brain twisted up! Anyhoo, I create an inventory against the detailed supply list.
On this site, after a bunch of digging I found a cross reference chart for D.J. to Keihin. Using the stage one mod, pipe and air box(snorkel removed & Uni filter)

Question 1.
I am using the DynoJet(D.J. from now on) gen 2 instructions with a Gen 1 carb. My carb had the 148 jet. Now replaced with a D.J. 150 jet.
How bad did I screw up? According to the reference chart the DJ 150 is same size as a Keihin 160. That's close to the stage DJ stage 2.

Q.2
The bike has run great until today, because after all the reading I am looking for things, like the bike lurches forward a bit while holding throttle steady in 2nd gear @2400rpms. From 3200 up the bike pulls hard. Much'0' better. The bike pops on deceleration. Not much, but it does pop. Kinda lime Harley D's do. Thought was my pipe.
The idle screw is 2 turns out. Not 2.5 like instructions read. That caused a lot old soot around the pipe end. So I back it down a bit.
How do I fix this? Is this a big problem that could cause damage?

(Still bothered a bit about the junk/paint markings in the oil.)
PJ
Screen shot of the chart in case anyone wanted it
 

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Most will suggest that overall the DJ suggestions are 1 to 3 steps Richer than ideal. Does your air box have at least four 1" holes added to the top cross-over area?

How is your overall fuel mileage?
 

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Discussion Starter #3
No holes, fuel mileage went waaaay down. Getting around 35-37 mpg. I was getting 45+ without trying. I think I will try going one step higher from stock. And maybe play around with the idle jet.
PJ
 

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The idle jet is a bit of a red herring. Going bigger on it if you are having trailing throttle lean pops will reduce or eliminate the lea pops. Severe lean popping usually happens after you have opened up the airbox and the exhaust. Going larger than required on the idle jet doesn't do anything because you would normally adjust the idle screw to proper running. If you were running well on a #38 at 3 turns out and put a #42 in, you'd probably wind up with the screw something like 1 1/2 turns out and it would run the same.

Poor mileage is a sign of one of two things. 1) you have a great running engine that is fun to ride and you run it at full throttle all the time and you have bugs in your teeth 2) the engine is running OK but is stupid rich and fuel is not turning into horsepower.

I have an opened-up airbox and exhaust and some head work and it runs pretty well with the usual KLX formula of the second clip from the top on a 142 jet. I ride pretty normally on the throttle and I have gotten 43.2mpg over the last 35,800 miles.
 

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Discussion Starter #5
Hi Tom. Thanks for the wisdom, I will replace the main Jet and open up the air box, air box mod, but yes, I do have a klr tooth brush just for riding 😁😁😁😁. My bike is so much fun. After reading your post, I realized I never stayed in 2nd gear for very long to notice and surely haven't kept it below 3k rpms.
 

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Hi Tom. Thanks for the wisdom, I will replace the main Jet and open up the air box, air box mod, but yes, I do have a klr tooth brush just for riding 😁😁😁😁. My bike is so much fun. After reading your post, I realized I never stayed in 2nd gear for very long to notice and surely haven't kept it below 3k rpms.
I'll suggest most of our riding is actually on the mid-range needle (3/8-7/8 throttle), so if after opening the air box for more air & leaning the main jet down two sizes doesn't improve the mileage much, one should lean the needle 1 clip position.
 

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Discussion Starter #7
Thank you PD. This forum has so many helpful and inspiring folks. It is great. Oh I can't forget to mention those who bring humor. Thank you everyone. I am so greatful for the help and inspiration.
PJ
 

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Yep, the reason your mileage is in the toilette is that your jetting is stupid rich - the DJ needle is OK but their jetting recommendations are ridiculous. I run a DJ needle in my 2001 but use the KLX kit jetting recommendations;

- 142.5 KH main, second clip, no shims
- stock 40 pilot with 2 turns on the fuel screw (42 with 1.75 turns might be better)

Snorkle-ectomy, 4 - 1" holes in the airbox top, Uni-filter and I run an FMF Q4, LV X3 or LEXX.

Dave
 

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Discussion Starter #9
Yep, the reason your mileage is in the toilette is that your jetting is stupid rich - the DJ needle is OK but their jetting recommendations are ridiculous. I run a DJ needle in my 2001 but use the KLX kit jetting recommendations;

- 142.5 KH main, second clip, no shims
- stock 40 pilot with 2 turns on the fuel screw (42 with 1.75 turns might be better)

Snorkle-ectomy, 4 - 1" holes in the airbox top, Uni-filter and I run an FMF Q4, LV X3 or LEXX.

Dave
Yes, doing the cross reference, DJ chart looks like 142 jet from their kit. The Keihen jet(stock on my bike) was 148.

Keihen 148 = DynoJet 142

This might explain why I used the richer jet. Here in NC, rain all day today and Friday. So, a good time to make the swap. Then Saturday Mownin I'm going for a ride.
I agree with the 1.75 turn out.

Does anyone have extra plugs for the air box? If so PM me with price my zip is 27921. Thanks.

I have a roll of filter foam for my ATV. That would work fine.

Seen a few on eBay but they come in a 16 pack, that's why I am asking.

PJ
 

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You mean filter plugs? Those things are unnecessary. Don't use them.
 
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ditto; filter plugs are counterproductive; all they do is add restriction and maintenance for no good reason

Dave
 

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You will be making the holes on the dirty side of the airbox. The holes are no different than the main hole in the airbox. The air filter, if properly maintained, is all the filtration you need.
 

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On real dirt bikes, the seat is the air box cover. Usually a 6" x 8" open area for the engine to inhale from, as sound deadening is not a factor!
 

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On real dirt bikes, the seat is the air box cover. Usually a 6" x 8" open area for the engine to inhale from, as sound deadening is not a factor!
Yep, my KTM300 didn't even have a left side on the airbox, it was covered by the sideplate, top was completely open.

Dave
 

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Discussion Starter #15
Thanks guys. That saves me time and money.
Here is a question for ya.
Wouldn't it be easier to just leave the right side cover off and just replace the right side panel?
Why or why not? Pick'en yur brain first this one. 😁😁😁
 

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Running with no airbox door is really loud. It's almost as bad as using a Supertrapp. I couldn't take it for more than a ride around the block in my flip flops, shorts, and tank top. Maybe it wouldn't have been so bad if I had a helmet on...

I have a pattern of holes drilled in the top half of the door. It doesn't seem to affect the carburetion except to improve flow. It's not overly loud, but there is a resonance between my pipe and the airbox at about 3500rpm. When they resonate it is rather loud. Once they fall out of resonance it is not that loud.
 

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Discussion Starter #18
PD,
thanks for the link. Wish I stumbled across that before I posted anything. Looks like I will just do the L mod and be happy with that.
Tom,
That 3500 rpm range is my average range. I have a terrible drone in 81T/A @2500rpm. I don't need it on my bike too. Plus I am sure the Police won't like it either. I am very satisfied with all the reponces. Your comment about bugs in the teeth was great! It reminded me of an old Ray Stevens song about a motorcyclist. "Speedball" I can't remember if that is the title or not. But its worth a You Tube search. Very funny song. Found it. It is called Speedball. Enjoy the song fellas.

https://youtu.be/J5qWHtaRjCo

PJ
 

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Well, I'm late as usual; but what they said - removing or modifying the door is a poor solution and, if nothing else, would provide a new lower spot for water to get in. There are zero downsides to the L mod or 4 - 1" holes in the top that I've been able to determine.


More airbox info from the late, great Cary Aspy;

A lot of missunderstanding with airbox issues.

First, the screen. Airflow gains are not linear. Removing the screen with an otherwise stock KLR airbox will only gain you 2 cfm. The engine won't know the differance. However, with a heavily modified airbox, the gain from removing the screen is 8 cfm. Depending on what else is done to the engine, you may make more power. I doubt that you'll feel it, but a dyno will show it. Butt-dyno's can detect very small low rpm changes, but don't detect higher rpm changes very well at all. You'll likely not detect it, but that does not mean it's not there.

Comparing screen removal to other models is wrong, particularly with the newer sportbikes. With them, the screen often serves another purpose as well. Air distribution in a 4 cyl sportbike can be a real problem, particularly with "ram air". Removing the screen on them can cause very real losses, depending on the model. That does NOT apply to the KLR.

Same thing with air filters. There is only about 2 cfm differance from the best filter (UNI), to the worst (K&N). With a modified airbox, that differance grows to 9 cfm.

Here is the flow chart:

Completely stock - 64.8cfm
Same - Remove snorkle - 74cfm
Same - With UNI filter - 76.2cfm
Same - Remove screen - 78.6cfm
Same - Small "L" cut - 85.1cfm
Same - Large "L" cut, open snorkle area further - 92.4
Same - Remove door - 103.2

Alternate - UNI filter, No snorkle, With screen, No door, No "L" cut - 95.4

All at 2" of water, tested at 1 1/2" and 3" and averaged to 2"

To answer the larger question, how much air can the KLR really use?
....................
A stock KLR about 70-80cfm. With a good pipe about 75-90cfm. A modified motor about 90-100cfm. Having a bit more capacity than you you need will not hurt anything. The effects are not linear though. Going from 65cfm to 75cfm you will likely notice, but going from 75 to 85 cfm you likely won't.

Part of the confusion might be due to the effects of the carb shimming. Since that mod is for a stock needle, the snorkle removal serves not just to add air, but to lean out the top end. The stock KLR till 07 is rich on the top. ( The 08 has a smaller main jet.) Airbox mods have much more effect on top end mixture, so, with the stock needle it also helps straighten out the fuel curve.

Finally the airbox door. You've got to carefull there. You don't have clean air there. It's flowing past that door when riding. You can easily create a partial low pressure area there, depending on wind direction, and where you place your leg!

Cary"


I do not recommend removing the backfire screen (PITA) or running without the airbox door for reasons that should be obvious.

Though a KLR isn't going to have a bunch more power no matter what you do, a KLX kit combined with the snorkle-ectomy and L mod or 4 - 1" holes will have it running properly. don't bother with the little 1" foam filters if you drill the holes - they are useless.

Cheers,
Dave



Dave
 

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Discussion Starter #20
Thanks. L mod, snorkel removed, and down sizing my jet. Remember, my stock jet for the 2000 gen 1 was 48. So I am going with a Dyno jet 142. It looks like I am going backwards, but the office size I am actually going up 1 size over stock.

As the bike sits now, I am 5 sizes larger😳
Than stock. Yikes!!!

From this point, using a DJ 142 is 1 size over stock. Turn my idle screw 1-3/4 out. Cut 4 1" holes for the L mod. The filter was washed and oiled 2 weeks ago when I changes oil. It should be fine. I will repost Saturday when mods are done. Hopefully, the rain will hold off long enough for a good test ride. Here on the East coast of NC, its been a wet wet riding season. I did pick a great set of Dry Bones gear from Bass Pro Shop. They are nice. Roll to tight small package. The hoodie works very well with my helmet, sometimes my helmet leaks, so the hoddie works to keep my neck dry and head warm.
PJ
 
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