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Need Diagnostic help !!!!

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On going problem for about 500 miles.

Intermitten issue--but getting more frequent:

Engine stall / drop-out / back fire

Hot,cold, some times on tip-in, mostly under load

Mainly stock 2007 dr650 18000 miles

driven daily, not rode hard

still has factory clutch

new plugs

recent valve adjustment (was a little tight)

new fuel valve( raptor manual valve)

side stand switch bypassed

wiring harness good-no frays very light wear

idles fine

please help:banghead:

How do I run tests on the stator/pick-up while riding?

Am I going to have to break it to diagnose??

Three things make an engine run; FUEL, FIRE, COMPRESSION

My hunch is that it is electical.

How do you isolate?

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Intermittent problems are the hardest to find. Be careful trouble shooting and don't add a second problem.

Does it completely stall or just miss fire a little?

Was anything changed just before the problem appeared?

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Easiest way to isolate wether or not it is an ignition problem is to have a remote(hand-holdable) unit that is triggered by attaching to the plug and your cap/wire attaches to it. Then you have access to what is happening between your ignition and the plug.

Before you do this, put in another brand new plug(new plugs can be bad right from the get-go) and, make sure that all of your fuel is clean and fresh, nothing floating about in the bowl.

If the signal from the coil is breaking-down, chek the cap/wire and coil for resistance(specs are on the net) while they are hot(very important).

Even if they read good, doesn't gaurantee they are not bad.

The only sure fire test after that is with a DSO(digital storage oscilliscope)

which is used in every-day automotive diagnosis, that can be attached and used in real-time.

Ignition pick-up coils can get covered in magnetic dust(debri) and may need to have the air-gap adjusted. Otherwise, the wiring from primary pick-up to ignition coil and sometomes even internal CDI circuit-board issues can occur.

(whew!) Hope some of this helps. Good luck!

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Great advice guys! Thanks alot for all the help!

The only thing that might clue one in, is a possibility of some foreign material that got caught in the case while I was resealing the left side case. Is that where the pickup is?

I have a lab scope and a logic probe available so I will tap in the trigger circuit of the coil and we'll find out what happens.

Do you know the color of the wire for the trigger?

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On going problem for about 500 miles.

Intermitten issue--but getting more frequent:

Engine stall / drop-out / back fire

Hot,cold, some times on tip-in, mostly under load

Three things make an engine run; FUEL, FIRE, COMPRESSION

My hunch is that it is electical.

How do you isolate?

Why electrical? If that's a concern, get electrical contact cleaner from your local automotive store, clean the CDI connectors and the spark plug boot. Be sure to unscrew the spark plug boot from the ignition coil wire and clean it thoroughly. Then go through all of the electrical checks with a voltmeter/ohmmeter as described in the manual. You can skip the CDI checks since your CDI seems to be working properly.

It sounds to me like you you have a lean fuel mixture. That can be caused by poor fuel delivery (bad tank vent), float problems, vacuum leaks, or other carb issues.

Try a few simple things first: unscrew the gas cap enough to allow plenty of air to get in. Check for air leaks between the carb and the cylinder and make sure all the screws are tight. Check your float level using a clear tube connected to the carb drain. This picture might help:

http://dr350.wikia.com/wiki/CV_Carburetor_tuning

Try adding a bit of choke and see if that helps. It adds more fuel so if your mixture is lean, it will make your bike run better. Too much fuel and it will bog, decrease performance, belch smoke, but it should not backfire or cut out.

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I kinda sounds like a fuel delivery issue...

But, I had my bike die intermittantly and randomly several months after getting it. It turned out to be a loose conection in the elcetrical behind the headlight; one of those little bullet-type connectors on a wire was just loose. I don't even remember what it was for, but that's an easy check to cross off your list first.

FYI, the bullet connection looked in tact but I was able to push it in an extra 1/8" and that made all the difference.

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