Muffler fell off and bike bogged down :-|

[YamiMami]

I'm new to this site, this is my first post.
I just got a '77 xs650 and could use some advice.

I was cruising at 65mph and my muffler falls off my headers.
(I have the Mac 2 in 1 exhaust)
Before I could find a place to make a U-turn the bike started bogging on one cylinder. The second cylinder shut down immediately after the first.

Now that I have everything back in the garage I'm looking for advice on what I should check first. Is it possible I burned my exhaust valves from running too lean? Should I check them first?

any advice is much appreciated
thanks

 

[ninskrillz]

Did you put the muffler back on yet?

 

[650Skull]

lots of people run open exhausts, (no mufflers on the headers), so the valves won't have burn't out in that short time. The bike will be jetted for mufflers so when it fell off it would have mucked up the jetting.

Re attach the muffler and all should be ok. make sure there are no leaks and trouble shoot why it fell off in the first place and correct.

Oh! and a welcome to the site. Pics of your bike is a necessity or no one will believe you have one

 

[Paulrxs650]

I would say put it back to how it was. I would doubt any lasting damage has been caused by a muffler dropping off.

However, if it were me, I would go through your bike front to back to ensure nothing else is going to fall off, break seize etc

 

[YamiMami]

looks like some bad stuff went down in that left cylinder. When I cycle the Pistons with the kickstarter I can hear scratching and its stiffer than normal. What's my move from here? Pull the head off and assess the damage?

 

[ninskrillz]

View attachment 57090looks like some bad stuff went down in that left cylinder. When I cycle the Pistons with the kickstarter I can hear scratching and its stiffer than normal. What's my move from here? Pull the head off and assess the damage?

Put the mufflers back on and start it?

 

[650Skull]

That bottom plug has been running lean.

Shine a light into the spark-plug hole, check out the bore and raise the piston and see if you can see anything.

Drain the oil and remove the sump plate and check for any metal peices.

Give it a compression test without starting the engine

 

[YamiMami]

After the muffler fell off, it ran good at various speeds (including idle) for 20 minutes before it died on me. I would not have been as worried if it would've died immediately after the muffler fell off. Wasn't able to find the muffler, it was an hour before I could go back and look for it. I guess somebody snatched it.
I couldn't see much through the spark plug holes.
Compression gets up to 110psi with 5-6 good kicks, I'm pumped its not toasted.
I cleaned the plugs and was able to get it running but it won't idle. I'll get some new plugs.
I tried creating back pressure with a rag in my hand but still can't get it to idle. White smoke comes out the intake when it stalls now.
Thanks for all the replies, I'll post an update once I drain the oil and look for evidence.

 

[YamiMami]

I finally got around to draining the oil and I'm really mad at myself for not doing this the day I got it.

barely half a qt of oil came out.

The large chunks seemed to be aluminum since they weren't attracted to the magnets. There was quite a bit of thick sludge that accumulated at the bottom of the sump pan.

This amount of garbage is really worrying me and I'm not sure if I should just fill her back up or what. I'd really appreciate any input/advice from anybody who has an idea of what I could be dealing with.

I also wanted to ask if anybody knows what's up with my side screen cover. It looks like there was an oil cooler there at one point or something. I'll pull it off this week and take a look inside.

thanks

 

[azman857]

buy an exhaust /muffler and fill the engine with fresh oil and run her. Start saveing for an overhaul. These are tough engines but even they have limits. I too ran my engine for short test runs (no rides just tuneing) with no oil. I nearly soiled myself when I checked the dipstick the first time. I've put about 5k miles on her since and recently went through the engine and noticed no damage from my experience.

 

[fredintoon]

Hi YamiMami and welcome,
Oh my, that engine is full of crud, eh?
Can you still buy flushing oil?
If not, a 50/50 mix of Bargain Harold engine oil and diesel fuel will do.
After the muffler replacement, fill with flushing oil, start and only run at idle for a short while with a fan blowing on the engine.
Drain, examine, repeat a few times.

 

[5twins]

What you're seeing is pretty typical of what you find when you first get one of these, the result of not frequent enough oil changes and filter cleanings in the bike's past. It took me 6 to 8K miles with filter and oil changes every 500 to 1000 miles before the filters started coming out relatively clean. Most of us acquire an extra sump plate and filters so we can have clean spares ready to swap in at oil change time. Then the dirty ones can be cleaned up at your leisure and made ready for the next change.

 

[YamiMami]

I flushed the engine enough to notice a difference on the screens.

The bits and pieces in the oil appear to be the cam chain guide (black plastic slivers and aluminum chunks).

I bought a new guide from mikesxs but won't be ready to pull the head anytime soon.

Does anyone know if I can get away with riding it until I can get around to replacing the cam chain and guide? It seems like this problem would be corrected, or at least lessened, by setting the chain tension correctly.

I have a video of my tensioner with the bike running but am having trouble uploading it.

It sounds fine at idle but I can definitely hear what I think is the cam chain (sounds like an old school fire alarm bell) when I rev it above 1,500rpm's.

Advice is always appreciated, thanks.