I have a 2000 Ds650 with a mikuni HSR 45mm Carb.
I bought the bike off of a friend with that carb already on it. The bike ran decent when i first got it but after an incedent with a piece of cloth getting sucked though the whole engine. it hasnt run right since. I have rebuilt the top end of the motor, rebuilt the carb ect ect. Now it makes it very clear it does not want to start! It takes me about 15 mins to get it going when its cold, and even starting fluid. Once it is warmed up and ran for a little bit... it fine. It starts right up. Im lost. It has a brand new battery as well as a brand new rectifier/voltage regulator. I talked to a guy from a locol harley shop today and he says that carb is way to big for the bike...i dont think so it ran fine before. It also has a ron wood cdi and larger intake ect ect. Any help would be greatly appreciated.
Thank You,
Dave

 

sounds like the choke not working to me.

 

Either the choke not working, or low compression.. Wouldn't hurt to do a compression test... Does it fire right up if you put a little gas in the plug hole?

 

LMAO Carb too bike for the bike. Does that guy even have a clue. We have tons of people running that carb, 48mm, 50mm, And some of us are even running dual 40mm carbs. That was funny. Sorry but I had to

As for it not starting, I would venture to guess choke also. But what exactly is it doing when trying to start it? Rebuilt top end, what cams and what is your valve clearence?

 

Thanks for your help guys,
The compression is good, as for the choke not working...thats kind of what we were going with but when the bike is running and i pull the choke it revs up. So the choke is doing something. As for the cams just stock cams and not sure what the valve clearance is. Had my machanic buddy do all that (above me)
When i try to start it cold it just turns over...and over and over. No responce at all. I have to jam the throttle wide open to get it to start wanting to do anything. It starts firing with every turn of the starter but doesnt take off on it own. After a while of that it eventually starts. Once its running and i give it a good rev it blows a whitsh plume out the muffler not sure if thats of any relivance.

any more help would be appreciated.
Thanks,
Dave Brendorfer

 

well that would eliminate the carb. if the fire is good and the bike runs good once its running i would check valve clearance. Ive seen tight valves cause this problem too. clearances are very close and they use shims to adjust them. Id check that.

 

Like Dragon said, that carb is FAR from being to big. I kind of doubt its a valve issue on a stock motor. Where do you live? How cold is it there? Are you using the choke to start it? Tell us more about the rag going through the motor. The white smoke isnt a big deal as long as it doesnt continue to happen after start up. Thats just all the fuel you pumped into it with the wide open throttle. What pilot jet is in it? Are you sure the pilot jet,or any of the jets arnt clogged? When you say you rebuilt the top end and the carb, what exactly did you do? One last thing, what about the air/fuel screw? Did it get accidentally get screwed shut? Try throwing a new set of plugs in it. That seems to be the magic fix more times than not LOL.

 

when the rag got sucked through... it litteraly went in the carb and came out the muffler. pulled the head and cleaned everything up and i had someone who ended up not knowing what they were doing help me set the timing...two new exaust valves later + took the head in and had done whatever needed done to right the situation, lapped ect.
At this point the bike ran good. Went out riding and everything was good exept a god awful bog midrange. Pulled the carb off tore it down, realized the main needle was bent to high heaven, replaced the needle cleaned everything and this is where we are now.
I live in cleveland Oh and it's in the 30-50 deg range right now.

 

Okay, now were on to something LOL. When you say "timing", I assume you mean the cam timing. That could very well be your major issue right there. In both the hard starting and the major bog. BUT, it could still be a carb issue. Have you rode it since you put the new needle in? Was the bog still there? At this point, I would rule out any head/valve issues. If you had the head off and everything new put in, I would say more than likely the guy shimmed it up right. Make that the last thing on your trouble shooting list.

But more than likely, if its 30 degrees there, your just dealing with a cold blooded, stubborn pig. Especially if after its warmed up it pops right off just fine and stays running and idling just fine. Ive got a quite a bit of experience with the TM/hsr carbs. On mine, even when it was hot out, I would sometimes need to choke it if it had been sitting along time.

 

The bog was before the needle change but after the cloth incedent and head work but before the needle change. the bog is gone or at least minimised after the needle change (i need to get some more riding time to see.) The point that the hard starting came into play was at the end of last summer...when the temp started dropping. but needing a little choke is an understatment. Im talking running the battery dead before she even considers fireing lol.