Hi,
I posted here about a month ago with a question about a 1982 Maxim 650 spraying gas out the drain holes in the exhaust pipes. Well I took the carbs off and cleaned them, and found that one of the needles was bad. So I put new needles and gaskets in all the carbs as well as two new floats. Now I can get it running and idling, but only with the choke open, and as soon as I close the choke, it'll die. I took the carbs off again, and adjusted the two new floats so they were at the same level as the old ones, and that didn't seem to make any difference. I'm thinking maybe I need to adjust them the other way? I'll be checking the fuel levels in the carbs later to see if that's the problem.

Anyway, my problem now is that while changing the oil, I apparently stripped the threads on the engine block where the main oil drain plug screws into. Not good, I know. My question now is does this need to be taken to a shop to have them rethread the hole, or can I use a larger drain plug or is there some other fix for this. Any help would again be appreciated. Thanks,

John

You my friend need a torque wrench. For the oil filler bolt you can use a cheaper deflection bar type as it doesn't need the percision of some of the fancy ones.

If it is stripped you have a few options - probably what they will do is put in a threaded insert type coil. Helicoil IRC... and yes probably best to have a shop do it.

On the idle issue - check the plugs. If it is running really rich on that cylander you can start there. I'd guess they were out quite a bit to compensate for the damaged needle and now with the new needle you'll have to adjust accordingly.

I'm not a carb expert at all. As far as I know what you need to do is:

Ensure you have the right size needles.
Ensure that the diaphrams are good
Ensure the float height is right

Check the plug for lean/rich for a basic indicator of your problems.

Then you should be getting into a carb sync and fuel mix. Colortune plugs and those fancy suction measuring tubie things - some-thing-or-other meter. Essentially you balance carb 1 and 2 to each other and 3 and 4 to each other. Then 1-2 balance with pair 3-4. As you balance you'll also be doing fuel mixture so its a bit of a cycle - fix one, then the other until it stops changing...

The choke on these bikes is actually an enrichment circuit. It adds fuel instead of restricting air. Therefore I would surmise that your carbs are lean. This could be due to the idle circuit having trash in it, the float level being too low or the pilot mixture screws set too lean. First thing you need to do is verify the fuel level in the carb bowls. If you take the carbs off for this then remove the bowls and check the pilot jet. If it is clear then check the starter circuit which is the brass tube that fits in the bowl. The small port in the bowl and the brass tube both should be sprayed with carb cleaner to verify that they are clear. Once the fuel level is right replace the carbs and fire it up. If it is still the same then a colortune plug is the best bet to check the pilot mixture screws. If you don't have this then start the bike and let it run for a minute or two and check the header pipes for warmth. Whichever pipes are cold are your lean cylinders. Turn the pilot screw for that cylinder counterclockwise 1/2 turn at a time until it fires. If it never fires then the carbs need a major cleaning.

Take them back off and carefully remove the pilot jets. Also in the float bowls is a hole that will need cleaned out as the is for the choke. Spray some contact cleaner in the hole in your float bowl and see if it shoots out the top. Also Through your pilot jets in the carb. Also check your intake boots for good sealing.