Hello my moto friends, I'm new to the ds 650 and just finished rebuilding the motor top to bottom, pretty sweet engine, however I cant get it to start for the life of me.The stator wires and trigger coil wires where melted by the exhaust and so on. Anyway, I set the cams with the tdc bolt, adjusted the valves to spec and all I get when cranking is a big backfire back through the mouth of the carb. I checked the spark and it has solid consistant spark on both plugs. Check the voltage from the trigger coil as per manual and it was less than spec so I replaced it and spaced it off the flywheel like the manual said. Now I have solid spark and the compression cold is around 110 psi. I've been through the carb twice and the jets are all clean. I'm really at a loss because I have all the basic elements for this thing to run. (gas, fire, compression, air) Is it possible to have spark and yet have a faulty cdi or ecu? any ideas fellas?

 

Your cams are off... Re-check the tdc bolt..

 

Thanks for the response brother, I'm headed to the shop this morning and will check the cams again. Do you know if there is a specific cam chain pin count between sprockets like there is on the suzuki's?

 

There are markings (lines) on the cam sprockets and markings on the plastic cahin rider that need to be lined up. Alot of times they can look to be right on but might be a tooth off. Adjust them with the tensioner in so that it doesn't rotate off when you reinstall it.
What were your gap settings? Did you put the key back in for the flywheel? If it slips at all you will get an ill running machine...

 

Alright, here's what we have.. I installed the tdc bolt to lock the crank, checked the cam timing with the pointers on the black cam chain block & their good. I set the plug gap to .65mm and re-checked valve clearance & their in spec. .15mm is good .16mm is to much & still, all I get is an ocassional pop through the carb. I hit it with a little either and she wanted to run for about 3 seconds and back to popping out the carb. is it possable the cdi is bad even though I still have spark? or is there a specific fuel screw setting? all the book said was at least 1 turn out.

 

".15mm is good .16mm is to much"

Where is it that you got this information? The correct gap settings are between .004 to .006.

 

this guy knows his ****, btw whats up dude i think i met u out at glamis halloween 09. your seth and tracys friend right?

 

Yep, that was me. Grenaded transmission on the F-350, not alot of riding that trip! Heading that way first thing in the morning. Taking my son down there for his first trip of the season. Well since Labor Day up at St. Anthony for him anyway.

 

thought so this is kevin the big guy that was out there, im headed out in the am as well.

 

Sorry bro, might have had turkey on my mind.. I'll have to check the book again. I pulled them of the top of my head.. might of had them confused with another unit.
gonna give it another look on monday..