engine miss on 04 klr 650

[bsman]

hi guys ..hoping someone can lead me the right direction. 04 klr 650.. 34,000 ks has developed a miss, started about two weeks ago firt crack of the throttle over 3500 after going thru town.. now is almost unrideable, seems to only be above 3500 rpm.. i see the tack drop right off when the miss stars, am really thinking electrical but am open to ideas..
i have over ridden the kick stand switch and someone else has done the clutch switch, it has a cracked choke cable, carb end, other than that is starts perfect and was running fine for the last 2000 ks,, thanks in advance.. bruce

 

[Sparkle]

Hi Bruce:

It might not be an electrical miss...sometimes a bike will run fine at low rpm and crap out at higher revs because it's simply not getting enough gas. Check your fuel line, filter and petcock valve and make sure your gas-tank air vent is clear. Try putting the petcock valve on "Prime" as it runs to see if it gets better...As you ride, loosen the fuel cap a bit to see if it gets better....

Change the spark-plug....and rev the bike at night in the dark while you watch for sparks around the coil and spark-plug lead.

Recheck the work done on the switch by-pass. For me a problem is usually the last thing I screwed with.

some guesses....

Sparkle

 

[islandswede]

Hi Bruce,
It sounds as if it could be the vacuum diaphragm in the petcock! Remove the petcock and disassemble. If the the diaphragm is broken it is clearly visible. The new part is about ten bucks. Or just cut a piece of gasket material and assemble the petcock without the vacuum stuff. You will also have to plug the vacuum hose on the petcock and carb side. You now have a "standard" petcock rather than a vacuum operated one. Great if you need gas for camping etc.
And don't look for the prime setting on the KLR, it doesn't have one.
Good luck

 

[volcon]

Ignition box. The give away is the loss of tach signal. Check by subsituting with known good unit.

 

[04klr]

dsbc forum in action,
a problem well described, and badda bing three short concise pretty frikin good responses, in a few hours.
sparkle, my buddy's 690 vapor locked due to a faulty gas tank vent. swede from the island, been there done the mod (after dumping the tank for the third time, now thats bad gas). volcon, good "pick-up" on the tach thing and quick an easy to troubleshoot .
all we need now is enuf time to pass for bsman to come back with the, WA-HOOOO!

 

[bsman]

thanks for the input

thanks for the input

thanks you all..... i will get started asap and let you know what happens.. hoping the ceapest but am expecting the most $$$$.. as usual
txs again bs
ps
if there are other ideas out there i'm still listening

 

[vortexman]

Just my two cents worth

Just my two cents worth

thanks you all..... i will get started asap and let you know what happens.. hoping the ceapest but am expecting the most $$$$.. as usual
txs again bs
ps
if there are other ideas out there i'm still listening

A bad ign coil can squelch a tach signal (CDI ignition). On my dirt bikes I spray a fine mist of water on coil and ign wire boot to rule out any ignition leakage, this is done while putting a light load on the engine (feathering the clutch).

The ignition coil and lead are very important and I replace them if three to five years old just because of the thermal cycling and harsh environment they must endure. I like to see the red flag before I jump to conclusions on customer bikes.

My next test is to artificially enrichen the fuel mixture with acetylene or propane again under light load feathering the clutch.

This rules out any fuel mixture or induction problems and I can move on to cyl leak down test. This can be done at home but should be done by an experienced engine man and rules out any internal engine problems.

Hope this helps.

 

[old trials guy]

I always start with the no brainers...replace the spark plug first cuz its cheap and easy to do. Tired plug is the number source of misfire on most engines. Second, plug cap because they either crack and bleed voltage or it becomes high resistance. I would put high tension coil on the bottom of the list as I have never experienced nor seen a bike with a bad coil. Sorry for disagreeing with you vortexman but coils never seem to be the root cause of misfire, they either work or don't work. I would go with Volcon on CDI box or possibly pulse coil.

otg

 

[joker650]

Rode to the beach one time with the bikes to have a BBQ. Well I forgot the lighter. SO I used the sparkplug from Connor's CRF230 to get somne gas burning and start the fire.
Well I forgot to put the plug wire on completly, and whenever he tried to get the rpm up it started to miss but ran just fine at lower RPM's....baaaad daaaad

 

[04klr]

nothin says redneck better than using a crf 230 and a can of chevron high test to light the family hot dog fire.

 

[vortexman]

Engine Miss

Engine Miss

I always start with the no brainers...replace the spark plug first cuz its cheap and easy to do. Tired plug is the number source of misfire on most engines. Second, plug cap because they either crack and bleed voltage or it becomes high resistance. I would put high tension coil on the bottom of the list as I have never experienced nor seen a bike with a bad coil. Sorry for disagreeing with you vortexman but coils never seem to be the root cause of misfire, they either work or don't work. I would go with Volcon on CDI box or possibly pulse coil.

otg

I thought I might clarify when I mean ign coil. I mean ign coil, coil lead, multi piece plug cap or boot.

Plugs and the boot or cap are big problem areas and for 80 bucks much cheaper to replace than a $400.00 stator or $338.00 CDI unit (parts US dollars)

It is my intention to assist the rider not debate basic mechanics and I think we will all agree getting the bike back into service should be the focus.

If the problem persists you can PM me. I am now curious as to what the resolution will be.

 

[old trials guy]

"It is my intention to assist the rider not debate basic mechanics and I think we will all agree getting the bike back into service should be the focus."

I think everyone is trying to help by sharing their experience. Doesn't make any of us right or wrong or trying to start something...please don't take offense.

otg

 

[bsman]

just a thanks to one and all and rick at kootenay cycle.. bike seems to be 100 % ... checked all ignition parts, tightened the plug cap to coil/plug lead, found a pin hole in fuel line, drained carb bowl and put some stp gas treatment in and took it for a spin to fortin corner and back thru king street with nary a miss
thanks for the input
bs

 

[bsman]

sorry rick... ALL SEASON MOTOR SPORTS.. best bunch to work with
bruce