Two Stroke Motocross

Two Stroke Motocross Forum => Technical => Topic started by: crazyjay on May 23, 2011, 11:22:55 AM

Title: 1981 it 465 starts then dies
Post by: crazyjay on May 23, 2011, 11:22:55 AM

Hello everyone brand new to site.I have been picking my brain for few days now and just cant figure this one out maybe somebody out there could help out.I was riding my it465 the other day then it just died left me stranded way out in the bush it starts then dies no throttle response. got it home checked every thing carb,new plug, compression,checked if the stator was loose was not has lots of spark.Any sugestion would be appreciaited thanks

Title: Re: 1981 it 465 starts then dies
Post by: factoryX on May 23, 2011, 11:41:58 AM

whats compression at?

Title: Re: 1981 it 465 starts then dies
Post by: crazyjay on May 23, 2011, 12:07:57 PM

compression is around 140

Title: Re: 1981 it 465 starts then dies
Post by: Coop on May 23, 2011, 12:24:37 PM

That's a little low, but generally if the compression is so low it won't run it won't even kick start. It sounds like it is kick staring ok, but then stalling after correct? You said you checked the carb, but did you throughly clean it? What did the reeds and air filter look like?

Title: Re: 1981 it 465 starts then dies
Post by: crazyjay on May 23, 2011, 12:29:53 PM

carb and filter clean it was running great then just died starts runs for about 5 secs with no throttle response left me stranded like 50kms in the bush

Title: Re: 1981 it 465 starts then dies
Post by: yo_marc on May 23, 2011, 12:41:54 PM

I'm wondering if it could be a plugged pilot circuit.

I had my pilot get plugged about 200 yards from my truck.  The bike acted like I fouled a plug.  I pushed it back, put a new plug in.. and nothing.  

Had bright spark, so I gave it another go at starting it.  I found the bike would run with the choke engaged, but when I disengaged it, the bike would sputter out shortly after.

I took the float bowl off, pulled the pilot jet, blew it clean and reassembled.  Bike ran great afterwards.

Title: Re: 1981 it 465 starts then dies
Post by: crazyjay on May 23, 2011, 12:46:05 PM

I am going outside right and pull the carb apart again let you know what I find

Title: Re: 1981 it 465 starts then dies
Post by: crazyjay on May 23, 2011, 01:26:09 PM

just went through the carb again spotless start run for few secs with no throttle response help

Title: Re: 1981 it 465 starts then dies
Post by: crazyjay on May 23, 2011, 04:23:46 PM

Figured it out it was the spark plug boot thanks everyone

Title: Re: 1981 it 465 starts then dies
Post by: SachsGS on May 24, 2011, 08:14:29 AM

It's funny how an electrical problem can fool a person into thinking it is a carb problem and vice versa.
I've seen Yamahas run with as little as 60 PSI compression.

Title: Re: 1981 it 465 starts then dies
Post by: WoodsRiderParts on June 23, 2011, 01:27:05 PM

How old is the spark arrestor?  I had a YZ465 with an old spark arrestor on it one time.  The old packing was so clogged with oil and spooge the bike would not run for long periods before dying.  Just a thought.

Title: Re: 1981 it 465 starts then dies
Post by: citabjockey on July 08, 2011, 10:15:48 PM

Glad you found the issue -- but I am curious How you found it? Good work!

Quote from: crazyjay on May 23, 2011, 04:23:46 PM

Figured it out it was the spark plug boot thanks everyone

Title: Re: 1981 it 465 starts then dies
Post by: crazyjay on July 18, 2011, 07:55:12 PM

I change my stator still same prob.Change the coil used the origanal boot still same  thing.Disconected the kill switch same thing. Change and checked everything twice and it was the only thing left so I took the one off my 1980yz250 that I was riding a fews days before without any probs.Put it one it started right up man did she smoke cleared up runs deadly now.