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Rebuilt '07 won't idle

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Well, not many posts here, but long time "lurker."

reaching out to you guru's out there for some help.

I recently had the top end rebuilt (oem piston, oem exhaust valves and KW SS intake valvles). Had everything done to spec through the local shop. I've gotten everything bolted on and shimmed within Honda's spec. I can get it started, it took roughly 5-6 kicks to get it going for the first time. However, it will only start with the choke on. It has a strange idle, almost like a rolling idle where it will drop and and climb again. Not drastically, however its definately noticeable.

Once I turn the choke off, bike dies immediately and 3/5 times, usually occurs with a small backfire. I've double checked the timing and it appears to be spot on. I've pulled the carb off and cleaned the jets since I knew it has been sitting for quite a while before I can get to replacing the top end. After these two tasks, the symptoms still occur.

Anyone out there care to be of some assistance? just looking for the next things to check out.

Greatly appreciated.

Ryan

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If I had to take a guess,I would say your cam timing is probably out a tooth.I like to put a straw or something in the spark plug hole to double check tdc.I also use the fly wheel and line up the mark to the right.I also think it helps to have the head bracket off,it's easier to line the cam sprocket up.

If the bike is harder to kick over and feels like it has a lot of compression this is most likely your issue.

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Bike is easy to kick, or at least it feels similar to before the rebuild. I used a small soft rod to make sure i was in fact at TDC and double checked the cam sprocket. looks to be dead on, or at least closer that it would be if I moved it up down a tooth on the chain.

Between that and cleaning the jets, I'm pretty much stuck scratching my head. As far as I've experienced in the past, timing and jets would be the main cause for these symptoms.

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I've made the cam timing mistake before and i'm pretty sure it gave me the same symptoms in the past.

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I would clean the pilot jet with a wire. Gasoline varnishes up the inside surface of jets and it doesn't take a lot before you effectively have a pilot jet that is too small. It looks clean, and the opening is clear, but the diameter of the opening is smaller than it needs to be.

Take a wire wheel (the kind you put in a drill) and pull a strand of wire out with a pair of pliers. Thread the wire through the pilot jet and roll the jet and wire up and down you pants leg so that the wire scrapes all around the inside of the jet.

I would also drain the gasoline out of the motorcycle and put the old motorcycle gasoline into your car. Amazing but true, gas can deteriorate quickly, and it looks like a mechanical problem when it is just deteriorated gasoline.

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I would be leaning towards the carb as well. The ramp and fall of idle sounds like your pilot circuit is not clean. If it has been awhile, then drain all gas and boil the carb. Also you may need to re-adjust your air/fuel screw now that you have a new top end. Sounds lean now. Also when you have your carb fully dis-assembled blow out all passages with compressed air. Good luck.

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Took the advice and went through the carb again. Unfortunately, its not the neighborly thing to do to start the bike at 11 so I will have to wait until the morning to see where it got me.

Thanks all for the help. We'll see how this goes...

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Took the advice and went through the carb again. Unfortunately, its not the neighborly thing to do to start the bike at 11 so I will have to wait until the morning to see where it got me.

Thanks all for the help. We'll see how this goes...

Did you reset the air/fuel screw to the stock settings? A flex jet really makes tuning the pilot circuit a breeze...

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At first start up, set the fuel screw to 2 turns out. And dont bother with trying to clean the pilot, just buy a new one. #42 is what you want. Also, if you had the slide out of the carb, you may want to make sure you got it back in the correct way. Its easy to get in upside down and it'll act exactly like your describing. The cut away in the slide goes to the bottom.

Verify the slide position first, then mess with the pilot.

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Well I moved the timing over a tooth to see if that did anything. I get a smoother idle while running, however it will still only idle with the choke on.

I can turn off the choke and blipp the throttle to keep it running, however once i let the throttle off i get the popping and it dies out.. I will turn the fuel screw to two turns and see what i get.

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My recommendation to you is to follow shawn-mc advice.I wouldn't go changing the cam timing unless your sure it's not correct.

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At first start up, set the fuel screw to 2 turns out. And dont bother with trying to clean the pilot, just buy a new one. #42 is what you want. Also, if you had the slide out of the carb, you may want to make sure you got it back in the correct way. Its easy to get in upside down and it'll act exactly like your describing. The cut away in the slide goes to the bottom.

Verify the slide position first, then mess with the pilot.

Agreed Shawn!! Did the same damn thing and same symptoms! Just a bone head move...

theDogger:thumbsup:

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