KLR riders out there

**Padmei** · 11th July 2010, 08:52

Thanks for the replys I'll head into the lab & see how I go.

**NordieBoy** · 11th July 2010, 11:05

If there's a localised thunderstorm with lightning, we'll know who to blame.

**Padmei** · 11th July 2010, 21:47

Took the clothes off Gonzo this morn & got into the carb to try to get rid of the thunderous backfiring.

I turned the pilot screw out 2 1/4 turns (from 1 3/4 turns) drilled the slide out 7/64th (already shimmed the needle) & then took it out for a blast round the forest.

Right from the start the difference was incredible. The throttle response was spot on. It felt as smooth as Zerax's flat slide carb DR I rode last weekend. The motor was smooth & the rear wheel spun with every twitch of the right hand. It felt like a completely different engine.

I think drilling the slide may have caused the most effect. I am very impressed with the carb mods & new pipe.

The only downside is the consistent backfiring on decel. I don't think there are any major exhaust leaks as the pipe fits are pretty snug & clamped down pretty well. I couldn't find the fresh air pipe valve thing until I reread this thread. I thought when I was looking atthe engine it was some kind of water pump.
I'll keep investigating.

**marks** · 11th July 2010, 22:21

Originally Posted by Padmei

I think drilling the slide may have caused the most effect. I am very impressed with the carb mods & new pipe.

The only downside is the consistent backfiring on decel. I don't think there are any major exhaust leaks as the pipe fits are pretty snug & clamped down pretty well. I couldn't find the fresh air pipe valve thing until I reread this thread. I thought when I was looking atthe engine it was some kind of water pump.
I'll keep investigating.

As you said - I think drilling the slide makes a big difference to the throttle response. Get rid of that air injection shit and the popping will dissapear

**NordieBoy** · 12th July 2010, 10:04

It's cool what small things can make big differences to the smile factor

**warewolf** · 12th July 2010, 11:57

Sounds like a good upgrade Padmei... I'm doing the same thing to my beastie this week.

Not sure that the exhaust air injection is entirely to blame for the popping. When I removed mine, the popping was noticeably reduced at slower speeds, but it's still there and seems as bad at higher speeds. It was the only thing I changed at that time, no jetting or exhaust. Bikes without exhaust air injection fitted at all (ex-factory) also pop on the overrun. Richer idle mixtures reduce it, but I'd rather have the more responsive/economic leaner idle and tolerate the popping.

I'm sure all of us who've ridden with Monseigneur Jardine are thankful he has dialed his out, though.

**pete376403** · 12th July 2010, 14:51

How tight are the pipe joins? Hose clips are not really suitable for pipe joins, especially if there is any sort of clearance between the pipes.

**Padmei** · 12th July 2010, 17:23

Originally Posted by pete376403

How tight are the pipe joins? Hose clips are not really suitable for pipe joins, especially if there is any sort of clearance between the pipes.

Thanks for the replys. I think you're all got valid points. I have read about the popping (I also now know the difference between backfiring & popping) on KLRnet & certainly the air valve seems to be the culprit, however sucking air in thru the joins could also be to blame. I thought naively that (like water) if the gasses are being forced out that direction that air couldn't be sucked back in.

Ww the richer the mixture the less responsive? Hows that work? By turning the mixture out I was enrichening the mixture?

**warewolf** · 12th July 2010, 18:25

Originally Posted by Padmei

Ww the richer the mixture the less responsive? Hows that work? By turning the mixture out I was enrichening the mixture?

A good mixture will be "crisp" and responsive. As you go richer, the response becomes sluggish, often described as "doughy". I notice it regularly on the 640A, since the air filter self-dusts. It gets dirty quickly and the bike runs richer, throttle response near/off-idle suffers - it's actually an indicator the filter needs attention.

These days bikes can be set up ex-factory quite lean at idle - I'm sure there's emissions tests done at idle. So going richer than OEM can be useful and increase throttle response. This latter is why lots of Americans tweak idle mixture, and why their PTB cover them with brass plugs to stop them!! (Their emissions rules being a bit stricter than ours, esp California)

However all too many ppl report the bike is set up & running well, then they go richer to reduce the popping... the implication being the bike is now not running so well.

The 640A has an adjustable mixture screw. We can set it right, you can go for a ride, then we can set it too rich & compare.

**Padmei** · 12th July 2010, 20:08

Just uploaded my first vid & want to see if I can embed it.

Not that interesting really...

**marks** · 12th July 2010, 20:34

Originally Posted by Padmei

Just uploaded my first vid & want to see if I can embed it.

Not that interesting really...

its a bit noisy

**NordieBoy** · 12th July 2010, 20:45

The laugh was nice and evil too

**Crim** · 25th July 2010, 14:34

I know this has been done before and DR footpegs fit the mighty KLR - but, as always, trying to save a bit of cash - anyone got a photo or can take one of what a KLR footpeg looks like without the rubber on it - thinking I may be able to attach some ground metal plates and make the exisiting more "off roady" - but don't want to start the process and then discover I buggered them and have to pay top whack for off the shelf replacements
Thanks, Crim

**Eddieb** · 25th July 2010, 17:00

Originally Posted by NordieBoy

The laugh was nice and evil too

+1, I liked the finale

**Padmei** · 25th July 2010, 17:34

Originally Posted by Crim

I know this has been done before and DR footpegs fit the mighty KLR - but, as always, trying to save a bit of cash - anyone got a photo or can take one of what a KLR footpeg looks like without the rubber on it - thinking I may be able to attach some ground metal plates and make the exisiting more "off roady" - but don't want to start the process and then discover I buggered them and have to pay top whack for off the shelf replacements
Thanks, Crim

Crim - it's nice to know there's someone as cheap as me out there.

I made my own & is very simple. I took off my shitty rubber bits then got some 20mm flat bar & bent it so it was snug around what was left of the existing pegs. This took a bit of grunting & hammering but I got it done.
I put it in the vice & with a grinder cut some V s in the bar. My weldermate then put 4 welds underneath & I sprayed it with some black paint - voila!!

It was a bit funny cos my engineer mates were watching & shaking their heads - they kept coming over to try & take over & do it 'properly' but as it was my project I kept them away.

If I was to do it again I would weld a couple of small spacer blocks either side of the pegs & make the area wider (length is good).

Woodman & I have had many discussions on the KLR footpegs & agree that they would be better set further back. Note the edge of the pegs worn away

. BTW If you haven't yet make sure you replace the footpeg bolts - they will strip or shear off when out riding - trust me we know.