Carb in Magician loose on engine seal

[pcast01]

I had a huge issue in my Magician today. It died when I came to a stop after I ran it around for a few minutes. I couldn't get it back running without putting the choke back on and even then it wouldn't stay. Turns out the seal on Carb was loose and smoke was coming out of it. I got it back to my house and took a closer look and the nuts were missing off of it?! I need to get the bolts but don't know the exact size. I am guessing 10mm bolt size but am not sure. Anyone know the size? Also since the vibration is most likely the culprit here, should I put loctite on these and most bolts on the magician?

[Megadan]

On the head side or carb flange? Should both be M6x1.00

[pcast01]

head side.

[Megadan]

Yeah, so those bolts should be an M6x1.0 metric thread. You can get them at Ace Hardware pretty easy. Toss a dab of blue loctite on the new ones when you install, but don't tighten them more than 15-20ft-lbs.

[pcast01]

Originally Posted by Megadan

Yeah, so those bolts should be an M6x1.0 metric thread. You can get them at Ace Hardware pretty easy. Toss a dab of blue loctite on the new ones when you install, but don't tighten them more than 15-20ft-lbs.

Thanks for you help Megadan. I was able to get it back on correctly but now I am still having the issue of not being able to keep the bike running. It starts out strong but then dies, only when I keep using the throttle does it stay running. How can I solve this?

[Megadan]

Originally Posted by pcast01

Thanks for you help Megadan. I was able to get it back on correctly but now I am still having the issue of not being able to keep the bike running. It starts out strong but then dies, only when I keep using the throttle does it stay running. How can I solve this?

Well, before going into further troubleshooting, let's start with the most common cause of running issues.

Check the valve lash. Set the intake and exhaust to .003"/.004" on a cold engine. You can find how to do this on youtube, just use the Hawk 250 in the search criteria. It uses the same engine, so everything else should be identical.

After trying that, report back and we can move forward.

[Megadan]

More often than not, running issues tend to be something very simple. It is just a process of elimination. By checking and eliminating the biggest and most common problems as variables it will help in narrowing down the actual issue.

One suggestion, replace the stock fuel line with a clear line. You can pick up some lawn and garden fuel hose at the parts store cheap. It's handy to have for seeing if fuel is actually flowing to the carb.

[Megadan]

Not a big deal with the wrong oil type. Maybe change the oil a bit sooner for the next go around just to ensure you got the rest of the "bad" stuff out, but it should be fine.

As far as the oil leak. Is it at the head gasket or the base of the cylinder where it meets the engine cases? This seems to pop up from time to time. You can check the head bolt torque to make sure one or two aren't loose. This will require taking the rocker assembly off, but it is pretty easy - 3 bolts. Then you will see the 4 head bolts. The torque spec is kind of generalized, but I have my head set to 28ft-lbs. Just go over them in a cross cross pattern like you would a 4 lug car wheel.

If that doesn't stop the leak then either the head gasket or base gasket may have been damaged during assembly. You can buy both as a pair for about 10-12 bucks on ebay.

As far as the bike starting, running, and sounding better. It's amazing what a proper valve adjustment can do ain't it?

The running issues you are experiencing aren't uncommon. To really get it to run properly it will require upping the main jet size to at least a 105, shimming the needle with at least 1 shim, and uncapping and turning the idle mixture screw out to around 1 1/2 turns from seated. This is a pretty good baseline carb setup for most stock Hawks and Magicians.

[pcast01]

Originally Posted by Megadan

Not a big deal with the wrong oil type. Maybe change the oil a bit sooner for the next go around just to ensure you got the rest of the "bad" stuff out, but it should be fine.

As far as the oil leak. Is it at the head gasket or the base of the cylinder where it meets the engine cases? This seems to pop up from time to time. You can check the head bolt torque to make sure one or two aren't loose. This will require taking the rocker assembly off, but it is pretty easy - 3 bolts. Then you will see the 4 head bolts. The torque spec is kind of generalized, but I have my head set to 28ft-lbs. Just go over them in a cross cross pattern like you would a 4 lug car wheel.

If that doesn't stop the leak then either the head gasket or base gasket may have been damaged during assembly. You can buy both as a pair for about 10-12 bucks on ebay.

As far as the bike starting, running, and sounding better. It's amazing what a proper valve adjustment can do ain't it?

The running issues you are experiencing aren't uncommon. To really get it to run properly it will require upping the main jet size to at least a 105, shimming the needle with at least 1 shim, and uncapping and turning the idle mixture screw out to around 1 1/2 turns from seated. This is a pretty good baseline carb setup for most stock Hawks and Magicians.

Thanks for all your insightful information. I tried to get it running and with no luck. The bike won't stay on without constant throttle with the choke on. So what could be the most likely culprit?

[Megadan]

Originally Posted by pcast01

Thanks for all your insightful information. I tried to get it running and with no luck. The bike won't stay on without constant throttle with the choke on. So what could be the most likely culprit?

Well, in general, it's too lean. If you leave the choke on until it is hot and then open the choke up (turn it off) does it run better, or does it only ever run with the choke on, no matter what?

[pcast01]

I can only keep it running with the choke on. I stayed at least 10 to 15 mins and I couldn't keep it running on half choke.

[Megadan]

That makes me suspect a vacuum leak. Check the condition of the O-ring seals on the intake to the head surface, and on the carb to the intake surface. Check the intake over very well for any rips, tears, or holes in the rubber and that the flange surfaces on it are flat.

[pcast01]

O-ring in Carb
Well I looked at the O-ring on the carb side and found this above.

I didn't pull out the other O-ring yet but it was snug in the seal.

[JerryHawk250]

Looks like you found the problem.

[pcast01]

Where can I find the same O-ring size at?