78 DT 400

[Odouls]

Hi Every one;

First of all I just want to say what a great site, I have been reading it for awile just for fun. Now I have a issue that has me puzzled.

My 78 DT 400 with 5000 miles on it starts on the first kick and runs great for 4 to 5 min then dies even while excelerating it just cuts out and will not start back up no even a hint of starting.

If I wait a hour or so it will start up again and do the same thing. I have had the carb cleaned and the petcock aswell it is getting fuel because when I pull the plug it is wet.

I realy apreciate any help that can be offerd.

Thanks Matt

[Airhead]

I'm wondering if you are losing the spark when the engine is hot.

Get another plug, take it with you on a ride and when it cuts out test to see if it is sparking.

is it a CDI ignition?...If so perhaps the pulser coil is breaking down when hot, you could prove this with a multimeter if you know the wire colour to the coil in question

[Odouls]

I'm wondering if you are losing the spark when the engine is hot.

Get another plug, take it with you on a ride and when it cuts out test to see if it is sparking.

is it a CDI ignition?...If so perhaps the pulser coil is breaking down when hot, you could prove this with a multimeter if you know the wire colour to the coil in question

I was thinking it was a heat thing as well I will try and run it tomarrow and switch plugs when it dies.

Do you know were I can find info on metering my cdi?

Thank you for your help.

Matt

[Airhead]

I was thinking it was a heat thing as well I will try and run it tomarrow and switch plugs when it dies.

Do you know were I can find info on metering my cdi?

Thank you for your help.

Matt

Matt i'm not sure what you are asking me, I dont know of any way to test a CDI, as far as i'm concerened you have to test everythinh else in the ignition cct and if all checks are good then the only thing to do then is to replace the CDI, there will be resistance values for coils in the magneto and the HT coil for example As yours is an intermittent fault you need to do the test when it breaks down if we can find the values for your bike For now though I would do the test to see if the spark has gone when the engine is hot so were on the right track.

So it is a CDI ignition then?

Paul

[Odouls]

Matt i'm not sure what you are asking me, I dont know of any way to test a CDI, as far as i'm concerened you have to test everythinh else in the ignition cct and if all checks are good then the only thing to do then is to replace the CDI, there will be resistance values for coils in the magneto and the HT coil for example As yours is an intermittent fault you need to do the test when it breaks down if we can find the values for your bike For now though I would do the test to see if the spark has gone when the engine is hot so were on the right track.

So it is a CDI ignition then?

Paul

Hi sorry for the late response I ende up moving and you all know how that can be. any way I tested a new plug when the bike was hot and no spark I ordered a CDI from ebay and the bike did the same thing, starts up runs great and then just like that no spark.

What would be my next step and thanks for all your help.

Matt

[Airhead]

Hi sorry for the late response I ende up moving and you all know how that can be. any way I tested a new plug when the bike was hot and no spark I ordered a CDI from ebay and the bike did the same thing, starts up runs great and then just like that no spark.

What would be my next step and thanks for all your help.

Matt

how many wires has the CDI got and what colours are they?

[Odouls]

how many wires has the CDI got and what colours are they?

I have a wht,blk,brn,orange and blk/wht stripe there is also a another black wire that is not connected to anything.

I tried changing spark plugs when it died and no spark. I'm thinking the coil?

Thanks for all your help.

Matt