[MrShake]

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Hey guys, I'm hoping to get out to work on the bike this weekend and I want to get some opinions on where to start.

The bike starts up with full choke right away and will run will the choke on all day at about 2500rpm. I have let it run for about 10 minutes that way, checking to see if I could eliminate the choke, and it was never able to run without it. It would drop down and die out.

The carbs have been off this bike and were cleaned without taking them apart.
Rubber parts are in good shape.
Timing Belts have been replaced within the last month.
Bike has the Dyna ignition.

I think thats all the important info... where would you start with this bike?

 

[Keno]

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clean and rebuild the carburetors if you are going to ride it. Sounds like the slow speed or idle jets are stopped up from sitting and drying out. Cannot be cleaned without tear down. Holes are to small to wash out trash or varnish. Good info at following -- Keno

http://www.randakks.com/TechTips.htm

 

[MrShake]

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When I say cleaned without taking them apart.. I should be more clear... I didn't seperate the carb bodies from the plenum or each other.. but I did remove all the jets and clean with compressed air and carb cleaner. Ran cleaner and air through passages (including under the puck).... Its possible I missed the air jet in the elbow, because I didn't know it was there.

 

[Broke Winger]

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they could be out of synch as well. Get a good look at the fel filter. Better yet just replace it. get a good strong flashlight and pull te sending unit out of the top of the suel tank shien yr light in there and get a look at you pick up screens. Might be time to pull the petcock adn give it a cleaning/rebuild. You can get a kit from ebay to rebuild the petcock.

Check for vacumn in the fuel tank. The vent in the lid may be plugged up.

 

[norton]

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I would say it's those idle jets that Keno mentioned. It's tough to get those little suckers cleaned out.

 

[Whiskerfish]

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Did you get the Idle jets under the rubber plug inbetween the two larger jets??

 

[MrShake]

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Yep, I got those idle jets out and ran carb cleaner and air through them.

However, I think the problem might be a little bigger that I had hoped for.

I've been working on the brakes a bit this weekend between the "in situ" carb clean method waiting times. After letting the carb cleaner sit... I started the bike and she ran ok. I pulled the plugs to check them and they seem a little sooty... while I had the plugs out, I put the compression tester on and the right side cylinders only read 90psi... I put a squirt or two of oil in the front cylinder and retested... it bumped up to 120psi. It looks to me like the heads need to come off again... grr..

Any thoughts or suggestions?

 

[Whiskerfish]

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Did you have the throttle wide open for the test? Makes a BIG Difference. If the bike has been sitting for a while I would be very comfortable with a 30 psi jump with the oil added. It will take some time for the rings to loosen back up and get a good seal again.

 

[sandcastcb750]

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Only running at 2500+ rpm would seem to indicate that the slow jets are plugged.

 

[MrShake]

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Whisker, I was thinking just that same thing, so I'm gonna focus on some other things..

I messed with the idle screw to get her to idle at 900ish rpm, and she will do it, albeit inconsistently as she warms up. I managed to keep her consistent enough to do a quick carb sync, so they are getting pretty close. After the sync... I went ahead and ran the bike for a few minutes in the garage... I'm getting a little popping out of the carbs through the air box... that leads me more to think a valve adjustment may be in order.