Wont run without choke, high idle.

686 Views 17 Replies 10 Participants Last post by MN Willie, 2 mo ago

TheShmeeet

Discussion Starter · 2 mo ago (Edited)

I ended up getting a fairly good looking 87 klr650 for 100 bucks, and it has some issues. The main one being it wont run without the choke and it generally idles at 2000 rpm or so. Never had anything this big in a bike and the bike shakes pretty good, is that normal?

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SvennysGarage96

· #2 · 2 mo ago

$100?! What a steal! Please post pictures, we would love to see it!

In my experience, carbureted bikes that will only run with the choke means the carb is dirty so it needs to be removed and cleaned thoroughly to get any old congealed gas out of the jets and passages. I was just working on my friend's 2007 Ninja 250 with the same problem. I don't have my manual in front of me, but I'm pretty sure KLRs are supposed to idle around 1200 rpm. As for the shaking, my 2017 shakes like hell and it's just part of the KLR charm. Good luck!

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TheShmeeet

Discussion Starter · #3 · 2 mo ago

SvennysGarage96 said:
$100?! What a steal! Please post pictures, we would love to see it!

In my experience, carbureted bikes that will only run with the choke means the carb is dirty so it needs to be removed and cleaned thoroughly to get any old congealed gas out of the jets and passages. I was just working on my friend's 2007 Ninja 250 with the same problem. I don't have my manual in front of me, but I'm pretty sure KLRs are supposed to idle around 1200 rpm. As for the shaking, my 2017 shakes like hell and it's just part of the KLR charm. Good luck!

Heck yeah, will definitley clean the carb, the bike was actually bought as a package deal with a few frames with some parts i needed but it came out to really be 100 bucks, the picture is what i took to show them so i coupd ask on price, it was found on its side.

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Six8five

· #4 · 2 mo ago

Running it with the choke on will overheat the exhaust and melt the air box.
Clean the carb and enjoy!

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ptxyz

· #5 · 2 mo ago

+1 on carb cleaning, an ultrasonic cleaner is the best tool for this job and you'll find other stuff to put in it.

vibrations come with the territory but, an adjustment of the balancer chain slack (aka doohickey), assuming the spring still has tension, might help.

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PeteK

· #6 · 2 mo ago

Welcome to the cult. The Koolaid is over on the table by the door.

First read this:
Common new KLR owner mistakes to avoid

Then read the stickies for "things common to all KLRs" and for the 1987-2007 models.
1987 through 2007 KLR650 Wrenching & Mods

There are videos of how to disassemble, clean and adjust the carb. BE DAMN SURE you get it clean per those instructions, or you will have to do it again. And again. And again, just to be sure. Like most of us have. And you'll get enough practice to be able to pull the carb off in 5 minutes flat. 😁

Where are you located? And add that to your profile. How many miles on the bike? Does anything else need fixing?

If it runs at all, you got a terrific deal for just $100. That's even better than the 1987 I picked up for just $250, but it had a plastic IMS tank on it, which was worth that much alone. Anyway, return it to good condition and it will serve you well.

Last, and most importantly, CHECK THE OIL at every fill up. Or you will learn the hard way.

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SirMarksAllot

· #7 · 2 mo ago

+1 on dirty carb and get a manual to properly check/adjust the balancer chain and inspect the tensioner for that chain. Keep us posted! And welcome to the obsession with the KLR!

CentralOregonKLR

· #8 · 2 mo ago

Mine did the same thing with the choke when I got it, I suspect bad gas from sitting may have clogged the pilot jet. I added Sea foam to the gas and let it mix in, ran it a while, and it cleaned it right up. I have rebuilt tons of motorcycle carburetors and agree with everyones opinion to do so. It always a good idea, but if you're in a pinch and need to ride it somewhere before you get parts, sea foam can be a miracle worker in my opinion.

As far as the shake that is more concerning, and I would check that out before I rode it anywhere personally.

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Damocles

· #9 · 2 mo ago

A perforated carb slide diaphragm, or a diaphragm air leak (common with mal-assembled carbs), can produce the symptoms described, in my experience. Your mileage may vary!

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pdwestman

· #10 · 2 mo ago

Damocles said:
A perforated carb slide diaphragm, or a diaphragm air leak (common with mal-assembled carbs), can produce the symptoms described, in my experience. Your mileage may vary!

I'll dis-agree with those statements.
With a CLEAN pilot jet and thoroughly cleaned 5 low speed outlets (in the KLR's CVK carb) into the throat of the carb, an engine will run fine & dandy up to about 1/8 throttle opening, only then will a non-responsive diaphragm slide (due to vacuum leakage) restrict further increase of carburetor opening. (Begins to run too rich because of lack of air flow under the non-opening slide.) The butterfly plate is just a request, vacuum controls the rest.

The OPs carburetor needs a thorough dis-assembly and cleaning and re-assembly with-out damaging either of the two diaphragms. Of course they may already be damaged from previous mechanic's errors or ethanol fuel & age.

Well written Keihin CVK carb theory, Care & Feeding Of The Keihin Carb READ it ALL.

Wyman Winn carb removal,

Grant Jensen (MCP) carb cleaning, KLR Keihin CVK40 carb Explained video

Four Souperdoo carb cleaning videos, "Care And Feeding Of The CVK40"

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Damocles

· #11 · 2 mo ago

I can only wish you had been present, when I experienced the symptoms listed.
Where were you when I NEEDED you, pdwestman?
Upon fixing a diaphragm air leak, the symptoms mentioned disappeared, anyway.
Just lucky, I guess!

Damocles

· #12 · 2 mo ago

My theory, now discredited, and perhaps even disproven, ran like this:
With diaphragm air leak, the slide cannot rise sufficiently (insufficient air pressure differential between venturi and ambient pressures).
Since the slide cannot rise as it should, the main jet is not uncovered as one might hope; insufficient fuel flows when the needle remains, "low-down."
Result Fuel-lean mixture, not readily combustible.
To get the CV-carbed engine to run at all in this situation, the ENRICHER (or, "choke") must be activated, providing sufficient fuel to make up for the lack from the main jet. No solution; running remains pretty ratty.
So, I thought (wrongly, as usual) the diaphragm air leak inhibited slide elevation, compromising needle extraction and inhibiting fuel flow from the main jet, resulting in a fuel-lean mixture, partially compensated by activating the enricher ("choke").

I apologize for my flawed analysis and fallacious conclusions. Some day, someone will discover the true consequences of a diaphragm air leak.

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SirMarksAllot

· #13 · 2 mo ago

Damocles said:
My theory, now discredited, and perhaps even disproven, ran like this:
With diaphragm air leak, the slide cannot rise sufficiently (insufficient air pressure differential between venturi and ambient pressures).
Since the slide cannot rise as it should, the main jet is not uncovered as one might hope; insufficient fuel flows when the needle remains, "low-down."
Result Fuel-lean mixture, not readily combustible.
To get the CV-carbed engine to run at all in this situation, the ENRICHER (or, "choke") must be activated, providing sufficient fuel to make up for the lack from the main jet. No solution; running remains pretty ratty.
So, I thought (wrongly, as usual) the diaphragm air leak inhibited slide elevation, compromising needle extraction and inhibiting fuel flow from the main jet, resulting in a fuel-lean mixture, partially compensated by activating the enricher ("choke").

I apologize for my flawed analysis and fallacious conclusions. Some day, someone will discover the true consequences of a diaphragm air leak.

You did say YMMV🤷🏼‍♂️🤣

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pdwestman

· #14 · 2 mo ago

Why did it appear that I had not posted #10 just NOW. Wound up with a double posting again.
Sorry.

pdwestman

· #15 · 2 mo ago

Damocles said:
With diaphragm air leak, the slide cannot rise sufficiently (insufficient air pressure differential between venturi and ambient pressures).
Since the slide cannot rise as it should, the main jet is not uncovered as one might hope; insufficient fuel flows when the needle remains, "low-down."
Result Fuel-lean mixture, not readily combustible.

I suggest that with a diaphragm operated slide that won't / can't rise for what ever reason, it causes the engine to run too Rich. Because it begins to act as a 'choke plate'.
The mid-range jet Needle Never completely seals the mid-range needle JET, much less completely sealing the main jet.

I've ridden customers bikes & atv's with clean pilot circuits & clean thru-out the carburetor, but with damaged throttle slide diaphragms (From a tiny pin-hole caused by a wrinkled diaphragm to gapping holes caused by carb cleaner rot or severely pinched sealing ribs.)
They will start from very cold with full enrichener, they will idle fine once warm enough, they will respond & accelerate nicely up to the point that the diaphragm should start lifting the slide, but won't rev beyond 'X' rpm (dependent upon how large of vacuum leak) with a load on the engine. The farther that one holds the throttle plate open, the worse they will run. Back-off the throttle plate & they will cruise at 'X' rpm for as many miles as needed, unless one needs more power to go up a steep hill (possibly any more than 1/8th throttle with a severely damaged diaphragm or a spring binding inside the slide).

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Damocles

· #16 · 2 mo ago

I stand corrected, ashamed of my apostasy, humble in my ignorance and my unfamiliarity with . . . well, things! My alleged experience? Must have been hallucinating. Again.

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SirMarksAllot

· #17 · 2 mo ago

pdwestman said:
Why did it appear that I had not posted #10 just NOW. Wound up with a double posting again.
Sorry.

I think the website has been doing some funky stuff. I got emails on some posts twice. Gotta love technology 🤪

MN Willie

· #18 · 2 mo ago

TheShmeeet said:
Heck yeah, will definitley clean the carb, the bike was actually bought as a package deal with a few frames with some parts i needed but it came out to really be 100 bucks, the picture is what i took to show them so i coupd ask on price, it was found on its side.

I'll take a dozen please!

GREAT Score!!!

Wishing you all the best with your Quest!

Willie

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