Hard starting Maxim, with an odd petcock twist

Hello, I'm new to the forum, a new rider, a new owner of a 1981 XJ 650 Maxim. When I bought it two weeks ago, it was running--started on the first try and I took it as fast as I felt comfortable on a 20 minute ride in the country. I noticed some vibrations, but otherwise, I was amazed at how well it ran, considering the owner said he rarely rode it. I brought it home and took it for a victory ride, and except for a rather high idle (1800), everything seemed to be working reasonably well.

However, a week later, the bike is refusing to start. Just cranking over and over, without any ignition, just an occasional single backfire.

I don't know much, but I decided it wouldn't hurt to take a look at the carbs. Yesterday, when I pulled the fuel tank, I discovered something that seems quite odd. When my petcock was set to the "off" position, fuel flowed as though it was wide open. When it was set to the "on" or "reserve", it slowed to an occasional drop. Again, I'm pretty new to motorcycles, but isn't this completely backwards?

I remember the former owner telling me he never adjusted the petcock, just kept it in the "on" position, and I guessed that maybe my storing the bike in the "off" position had allowed fuel to flood the carbs.

Sure enough, when I pulled the carbs, several ounces of fuel drained out of them. I thought this was odd, but was also relieved, as it seemed to explain my hard starting issue. I quickly did a cursory cleaning of the carbs, replaced, put everything back together, and tried firing it up.

Same symptoms. Still no start--just the one backfire.

I saw somebody posted a detailed how-to on how to clean the carbs and check the float level, so I think I'll try that next weekend. Anybody have any other suggestions?

 

Is your petc0ck the factory one? or a replacement?

If it's factory, the positions are Res-On-Prime

So what you think is OFF is actually Prime, and it's working correctly.

 

If the carbs didn't stop the gas (floats that stick or don't seal) then your engine crankcase oil probably has a bunch of gas in it now. Sniff your oil and check the level BEFORE you start the engine again!

 

Give us some more info, too. How many miles on the bike, and how much do you know about the maintenance needs and recommissioning of an old XJ? (I don't want to type a bunch of stuff or link you to a bunch of posts if you already know about the serious safety hazards of old brake shoes, old brake lines, old tires, not checking your valve clearances, etc.) If you don't know what I'm referring to, do some looking up real quick and see!

 

Wizard: Yes--you're right, it's a factory petc0ck. I just looked and I could make out "PRI" in the right hand position.

3rd Gear: At least one of the floats was sticky, so I'll check the crank case.

29,000 miles, but I don't have a very complete maintenance record. The previous owner rode it occasionally, and I think did repairs as necessary, but certainly didn't do a lot of preventative maintenance. The front calipers were recently rebuilt and that brake line appears to be new and in good condition. I have no idea about the rear brakes, other than that they feel great--stronger than other bikes I've ridden.

But yes, please let me know the major safety concerns and I'd love to see any useful links--both DIY guides or good parts vendors. I'm happy to work my way through the list on the weekends, and don't intend to do any serious riding until the bike is safe.

 

The best vender for these bikes is Len at XJ4ever. Just click the banner on top of this page. Everyone here will tell you the same thing awesome service, and great pricing on new parts. Or send a PM to Chacal, which is Len. They carry everything you could ever need and he/they know what they are talking about when it comes to these bikes. So, if you give him the right info you can be assured that you are getting the right part for your bike!

 

Check your rear brakes for delamination, tire date codes, valve shim clearances, clean/rebuild your carbs (search for "in the church of clean" and (the whole nine yards"), rebuild your petcock.... that should be a great start for you

 

Oh, I see "wizard" and "3rd gear" aren't names, they are rankings... I'm a moron.

Thanks for all of those tips, everybody. Will get to researching and working over the next few weeks. Doc2029, I'm in Charlottesville, so we're practically neighbors. I'll update my profile and do a little more research on exactly what model I have etc.

 

Jpdukes, yeah not far at all from one another well a good hours ride. I ride up to your area a lot using various routes. my fave is 33 Staples Mill rd/Mountain Rd to 15 (James Madison) to 53 (Thomas Jefferson) to 29 in to C'ville.

Welcome aboard enjoy the bike. I can lend a hand where I can, but I haven't do a whole lot on my bike (yet) Though I am ripping it apart this weekend to check the valves and to figure out what shims I need to order.

 

I'm right in there with you guys. I'm at the epicenter of activites in Mineral! I just put new tires on mine this weekend, but I don't have the back wheel on yet because i am also putting in new brake shoes just because they are old. I should have mine going again next week! I've felt so many aftershocks I'm starting to feel aftershocks even when there aren't!

 

Well, I was driving from Charlottesville to Richmond at the time of the Quake, just passing through Mineral. So I got us all covered. Staples Mill Road is a favorite drive, but I have yet to do it on the bike. I'm still having the starting issue, and plan to do a full carb cleaning this coming weekend, and run down a few other things, so we'll see where we get.

 

Good luck, it's not horribly difficult!