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Corp_T
08-18-2012, 01:31 AM
I'm trying to figure out the best course here.

I was riding to work and heard a slight tapping, figured maybe the timing was a tad off or the valve needed to be adjusted. No biggie, I'll do it this weekend. I hop on to ride home and ~10 miles into my ride I start hearing what sounds like a grinding metal noise whenever I give the throttle a good twist coming from the engine. If I ease up it seems to go away. After another ~10 miles it won't stop ticking. Another 5 miles and there's a LOUD POP a dozen backfires and she dead.

I pull over and smell burning something and there's a faint trail of smoke coming from the left side of the engine. If I try and start it it just backfires and smells horrific. Nothing visual seems out of the ordinary that I've seen, I plan on giving it a good look see tomorrow after work.

I'm fairly mechanically inclined, do I try stripping the engine, toss it in the trash, or what. My goal is to sell this once it's running or "accidentally" lit on fire and get a more reliable modern commuter but I don't want to put hundreds of hours or dollars into fixing it.

Any suggestions as to what it sounds like and how much work we're talking. If it's not too bad but complicated I may just send it to a mechanic and have them do it, otherwise I'd like to save the cash and do it myself.

Doc13
08-18-2012, 02:13 AM
lol, you're "fairly mechanically inlcined" yet you chose to give it g as when you hearda grinding metal sound. Nice work, you won't know till you tear it open.

KC

theMelvster6
08-18-2012, 02:13 AM
Honestly it is hard you diagnose unless It happened to me personally. A lot of times it is valve train related. Stuck lifter, bent push rod, stuck valve, etc. The only sure way to know the culprit is tear down the engine....start at the top and work your way down to the cases. Ever get an CEL? For heat? Oil? Etc. Does it still turn over? How bout electrical? Anything happen with electrical that you've noticed? Get out the trusty shop manual! And get friendly with it! These machines are fairly simple...don't be affraid to do a tear down. Document it, label every bolt, take pictures, etc. I've torn into my share of motors and just place bolts, nuts, spacers, etc. In a bin...but never label it. As time goes by you'll forget where they came from unless you've done it a thousand times. The worst is getting it back together and having left over hardware!!!! IF YOU TAKE HER APART, LABEL EVERYTHING!! LOL ziploc bags, masking tape, tags...just label it!! Have confidence! Ok, ready GO!

Corp_T
08-18-2012, 02:17 AM
I honestly wasn't sure what the noise was, I was hearing it at freeway speeds. I suspected the valves needed adjusted or the timing was slightly off. I only had 20 miles left to go and really no other choice than to keep going.

It does still turn over and if I give it gas it coughs a little but it doesn't start. It'll eventually backfire and smell horrible. There were no other indicators other than the tapping and a slight bogging once and awhile that I attributed to an occasional misfire that I was going to check out over the weekend.

theMelvster6
08-18-2012, 02:31 AM
Smoke and awful smell...most likely oil burning. Backfire through exhaust or intake? Man...there are way too many plausible causes. Just pull the engine and get after it. Pay close attention to damaged areas as you pull her apart.

freak2180
08-18-2012, 02:37 AM
I suspected the valves needed adjusted or the timing was slightly off

If we are talking XB series then nope to both. lifters are self adjusting and only way the timing is off is if you have messed with it or had the motor apart. Sounds like oil pump went and took the motor with it.


I only had 20 miles left to go and really no other choice than to keep going.

There is always an option..... Stop and call a freind or relitive to come pick ya up.

Doc13
08-18-2012, 02:41 AM
It's cheaper to buy someone elses gas rather than buy a new bike, then again I wouldn't trade my bolt for "a more reliable modern commuter" anyway.

Good luck and God speed with the repairs.

Stillonit
08-18-2012, 04:05 AM
compression check will give you an idea what cylinder or cylinders failed this is the easy part . if cylinder low or no compression. Then rotate motor and remove the rocker cover and look at if the cam is operating the rockers correctly
in respect to the timing. and then Time to get the shop manual. the cam setup is very unusual compared to 95%of other motor you will find out there. I hope it something simple like a bad rocker. good luck.

Stillonit
08-18-2012, 04:11 AM
oops this is a blast post... you have just one cylinder.. i hope you can pull the rocker cover the way it sits .

Iamarchangel
08-18-2012, 06:41 AM
Here's an easy test: remove the oil pressure switch. Crank the engine over. If oil spurts out, my suspicions are wrong.

If no oil comes out, the oil pump gear is toast and took out the cam gears and oil pump.

Corp_T
08-18-2012, 05:48 PM
I started tearing it apart and I haven't been able to remove parts of the engine yet but I did notice that my spark plug is crushed...Is it safe to assume either the engine is toast or need total rebuilding?

theMelvster6
08-19-2012, 04:17 AM
If no parts came through the block that is a good sign:D crushed spark plug would indicate that the piston came up and wacked it. Best case scenerio is the bottom end is ok and just rebuild the top end, worst case scenerio something in the bottom let go and requiring complete rebuild or new engine.