First off, I know this is an ATV forum and I'm asking about a motorcycle issue. But because these are the same engines and parts, I thought I'd give it a shot.

Have a DB10 brand new in Oct. 2019. Ran fine for 3 runs. On the 4th, it started to require full throttle to stay running. Then stopped starting all together. Research said it was the carburetor. Replacing that and I managed to get it started once with an immediate die and then never again. Checked carb settings, good, checked fuel flow, good, checked spark, good, checked battery, battery was weak.

Got a new battery and tried again. Still no start. Threw a different carb on there from my second bike I own and it started, but won't stay idling. Told manufacture, was sent a new carb, and swapped everything back on the second bike with the NEW new carb being put onto the DB10. It starts, but won't stay running unless I throttle it.

At this point, I'm at a loss on what it is. Valves? The only thing I can't do is adjust the valve as my valve slips won't fit. Before I go buying even more parts, I'd like to get some info on what this could be.

Thanks in advance and sorry it isn't an ATV

 

Set the valves to give some clearance, correct is about 003" but so you can just feel that there is clearance will be OK to try, and the bike should then run if closed up valves were the problem. Any "new" carb will need the throttle stop setting to suit idle of your engine though. Have you set idle speed?

 

I did, yea. I got it running last night, though. I think it was a combination of both the valves and a bad pilot jet. I replaced the jet and it works now.

Thanks for the valve info.

 

How do you adjust the carb because that's what I'm stuck on for the same bike

 

The throttle stop screw (idle speed) is on the side of the slide, it has a taper on the screw. The slide drops down as you take your finger off the throttle until it sits on the stop screw, screw in and the slide can't drop as far, increasing idle speed, screw out and it slows idle speed. Other adjusters shouldn't need altering unless you have fitted a new carb, or someone has been messing with them. Slow running mixture needle is just in front of the idle speed screw on the little Honda carb, if speed increases when you turn slow running screw out, keep going until speed starts to slow, then back until it again falls then back to half way between. If speed starts to fall if you screw out, screw in instead, same again, once revs start to fall, back out, etc. Main jet may be adjustable by changing which groove the circlip is in, on the needle in the slide. They don't always have more than one groove though.