New owner, new member, new problem!

MisterMohawk · Posted: June 5, 2009, 1:31 pm Post subject: New owner, new member, new problem!

First off: howdy. Second: help! Just bought a '77 650. Was delivered Wed. with a mostly dead battery- the shipper had left the light switch, which is not wired through the ignition switch, on for a while. I kicked it over a few times and it started fine. I ran it around the block and went back to work. After registering it yesterday I came home and kicked the bike over to start it (I don't have a battery charger). Started up fine and it had run for about five seconds on the choke before I shut it off as a National Grid meter-reader walked up asking where my meter was. Less than two minutes later I came back out to restart it and...nothing!

It's got stock carbs, Boyer ignition and stock compression. I've got fuel to the cylinders and spark at the plugs. I hooked a jumper box up to the battery and it just cranks over without firing. After having run fine on two occasions I phoned the guy who sold me the bike- also the guy who did all the work on it- to ask his opinion figuring he'd know the bike best. He had no idea. Check fuel, air, spark was his advice and those things are fine.

I'm perfectly capable of working on the bike but I'm horrible at diagnosis so I thought I'd solicit a few opinions. Any advice is appreciated!

Edit: Spark looks a bit weak; only had time to do a visual verification that I do, in fact, have power to the plugs.

jurob · Full Member Joined: May 16, 2009 Posts: 21

charge the battery completely before doing anything else. trickle charger from walmart for under 30

nokitov

If charging doesn't help, a new battery at Advance Auto was about $35.00 last summer. But should still trickle charge before using

yamalama · Full Member Joined: Nov 14, 2008 Posts: 26

you may want to look at the battery being low on charge. boyers need a full charge to run right, PS dont just pull the spark plug cap off to check for spark, it may damage the boyer. you can buy a volt meter at harbor freight for about $4 to check the battery.

MisterMohawk

Brought a charger home from the shop, I'll leave it on tonight, see what tomorrow brings.

MisterMohawk

Result! The bike had BPR7EIX plugs in when I bought it. I ran out and bought a pair of BPR7ES's and threw them in. Kicked right over, idled and revved up fine. It's pouring out so I didn't ride around. So...fouled plugs. But why? Must have something to do with running rich with the choke open for just a moment and shutting it off. Maybe? I'm glad I know what the problem is but I want to know why. Ideas?

nokitov

When you say it's pouring out, you mean gasoline? Sounds like a float is stuck in the down or open position. I can't remember if you can remove the float bowl with out removing the carbs. I think it's kind of hard. My old Honda 750 had wire snaps that helped make it easy but I know the XS does not have wire snaps.

gordo

I believe he ment rain, as we had torrential down poor's the last couple of days.

MisterMohawk

gordo wrote:

I believe he ment rain, as we had torrential down poor's the last couple of days.

Oops. Correct, I did mean rain. Should have been specific when discussing carb issues an pouring, flowing or otherwise. So any ideas? Took a ride out this lovely morning and had no problems at all. I'm at a loss for what caused that problem.

nokitov

My bad

gordo

The bpr7eix plug's are the iridium equal to bp7es plug's. I guess dyno test's showed that the iridium made a little more horsepower. I would suggest that you have a look at the carb's, jet sizes,float level's,ect.
Sometime's, a choke left on too long can foul the plug's, and mostly it's from too large a jet size, usually on the main's. There is a good carb. guide on the xs 650 garage site. Check that for your starting point on the jet size's needed. Your bike should have the bs38 carb's, good for ease of tuning on a modified engine. Good luck Hawk,,,Gordo,,,(You could ask the PO or builder what they used in the carb's for jet's, maybe they remember.) Very Happy

xsleo

Generally speaking, PO's are PO's for a reason, they don't know squat. work with the folks on here or the garasge and you will get the bike right.

nokitov

Hey leo
How hard was the switch to rear disk brakes and did you just swap from another bike or order new parts? Any regrets or best thing you ever did...somewhere in between?

xsleo

Doing the swap was not to hard. Got most parts from ebay. Getting the rear wheel spaced was one thing, couldn't find the right spacer, ground down one that was a bit thick. Getting the mastercylinder mounts on the frame was the trickest part. Looked at lots of pics, Brazed on a pair of allthread unions/connectors on. It works very well. Well worth the trouble. The only thing is that I have a mag wheel on the rear. a spoked wheel would look better. I have a thread on how I did it. Go to forum index, scroll down to frankinbike, click on wheels,brakesand controls. page 3 I think. " I got brakes " Is the thread.

What Happened to 650rider.com?

Yamaha xs650