The pilot and starter are definitely too rich (my wr450 takes a 65 starter and 48 pilot with the extra 50ccs of displacement and higher compression, for example) and the main is not as off but still rich if I were to estimate. With the carb out, i'd research jetting sizes for starter, pilot and main, figure out what sizes might work best then get them from your local shop they should have FCR jets as most modern MX bikes use them. Did you undo the bearing caps, release chain tension or anything besides just sticking a shim in between the bucket and lobe? Are you following proper procedure for checking valves? I would not predict a DRZ to be that far out already, but the world is a strange place sometimes.

If it's just valves being out of spec, it's best to get them into spec first and foremost. A little overlap is normal but wouldn't be noticeable. If the bike is sucking in air through the exhaust, it's very likely you are very much out of spec on an exhaust valve or the timing is incorrect and the exhaust valves are still open on the intake stroke, so be damn sure it's vacuum that's occurring. especially since it sucks a little air in.

05 out of spec enough for the bike not to start? or is there another reason why the bike isnt starting? (I have spark, fuel and air) There was good compression while it was running but Its hard to gauge without testing it. is it possible that this would happen with just out of spec valves, or would it only suck air in if the valve was burned and something needed to be replaced?

I read that it is a sign of valve problems. One thing I noticed was that when its cranking over (but not starting), I put my hand on the exhaust and it almost feels like its sucking in air instead if blowing it out. It at least started before, and all I did was clean the carb out. I got it to start up twice, for about half a second before it died. It has been hard to start when cold, but what I dont understand is why its not starting now. 05mm out of spec, and one intake is perfect, but the other ones are right on the line. I also checked the valves and this is what I came up with.įrom my check I see that one exhaust is. I took the carb back off and made sure it was working how it should be. I just took the carb apart and cleaned it, when I reassembled it the bike wouldnt start, I drained the battery and had to recharge it. My bike has had problems starting cold, but when its gets warmed up it works great and will start right back up. Here are the notes I took down for valves. I posted the same question inside my drz400sm thread but figure itll get more attention here.Īlright, well I just checked the valves, replaced the plug, and took the carb back off and made sure everything was put together correctly.

Sucking in air at the exhaust