What did you do with your XS today?

Was riding down Hwy 401 on my way home when the bike suddenly started to loose power. Checked the gas gauge and still had 3/4 tank. Switched petcock to Prime just in case. Down shifted to 5th and planned to take the next exit, about 3 km away. Kept loosing speed despite WOT. Down to 4th and loosing speed faster. Pulled off to the shoulder before I dropped below 90 kph as everybody was in a rush to get home and I didn't want to become a statistic.

I could smell gasoline as soon as I came to a stop and the engine was barely able to idle. Looked down and gas was running out of the left air filter. Thankfully I was on a slight uphill grade at this time so the gas was not pouring into the engine. I quickly switched the petcock back to Run and killed the engine as gas was now running onto the hot left exhaust pipe. I grabbed my fire extinguisher and got some distance between me and the bike while I made some calls. Nobody could come with a trailer any time soon. Not surprising, I'm the guy that usually gets called to help. I thought about calling a tow truck, but that would have cost me a couple days pay. So I grabbed the tool kit and pulled the carbs at the side of the highway with cars and transport trucks whizzing past 1/2 a lane away. By the time I had the float bowl off there was noting wrong to see. Re-assembled the carb, connected the fuel line and tested. Seemed fine, so back together and rolling in just over 30 minutes. I can only guess that the float had gotten jammed open That was fun.

I'm going to pull the carbs again and have a closer look, obviously something isn't right. But that can wait for tomorrow.

Rode it twice this week, long brisk rides, handles fine, just as predicted with the sprockets I have on, it is buzzy at 100kph(6krpm) but still has some in the tank for more.1st gear has been rendered almost useless has I have to get to 2nd within 5m...but I kinda knew all of that going in.
The bike lost a lot of weight so vibration at speed is l bit more than I expected.
Checked the plugs...but I am no plug reader...what exactly do I check?... electrode, ceramic isolator, top of threads?... all of the above?... went around the Web and not all people say the same...and apparently plug reading isn't even a thing anymore...but I am NOT forking the money to dyno this thing.
All in all everything works fine.

The base of the ceramic insulator is what the pros look at. They even have a fancy magnifying glass that holds the plug with a built in light.

What kind of vibration? Is it speed or engine RPM related? Excess chain slack can cause vibrations, but I'd rather have excess slack than not enough.

here's my new Avon Road Rider tires plus my bf just installed my newer front fender!

16VGTIDave said:

The base of the ceramic insulator is what the pros look at. They even have a fancy magnifying glass that holds the plug with a built in light.

What kind of vibration? Is it speed or engine RPM related? Excess chain slack can cause vibrations, but I'd rather have excess slack than not enough.

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Thanks.vibration in the front end mostly (feels like the front is kinda light at 90-100 kph)
Keep in mind I have clip ons so any vibration would be felt directly.
Chain slack is within specs.
One thing I forgot ...(I just realised this) is balancing the wheels after the new rubber...
Will get to that soon

Tire balance could certainly be a cause.

One thing most don't consider is the bike's geometry. Reducing the rake and/or trail can have serious consequences regarding the bikes stability. Lowering the front, or raising the rear, will reduce both the rake and trail. Sure, the bike will turn in quickly, but it can also become twitchy or nervous the higher the speed. Tire sizes and pressures also play a factor. Lots to consider!

When deciding to pass a couple slow cars, be sure you know what gear you are in before performing a double downshift. While the acceleration is brisk above 8k RPM, one must be prepared to up shift quickly lest they run into the red on the tach. Thankfully my rev limiter did its job, though I doubt the pokey drivers appreciated the flames and noise as I "exploded" past them.

In my defense, it was late, I'd been in the saddle for just over 5 hours, and I really wanted to get home to dinner and a cold beer.

lol. Give 'em hell(fire) Dave!

16VGTIDave said:

"... though I doubt the pokey drivers appreciated the flames and noise as I "exploded" past them."

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Looks like I blew the engine. I heard a noise and before I could pull off the road the engine cut out with a nasty rattling noise. Now it won't turn over, so I guess the timing chain let go and pistons met valves.

At least I have cell coverage while I wait for a trailer and ride home...

16VGTIDave said:

Looks like I blew the engine. I heard a noise and before I could pull off the road the engine cut out with a nasty rattling noise. Now it won't turn over, so I guess the timing chain let go and pistons met valves.

At least I have cell coverage while I wait for a trailer and ride home...

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Sorry to hear the news. Hopefully the damage isn't to bad inside. Not the best time of year to start a winter project either.

That sucks. A least you where not hurt. I would start looking for another motor. You didn't get many miles on that one.

The autopsy will begin in the morning...

16VGTIDave said:

The autopsy will begin in the morning...

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You will probably start tonight though I know it would be bugging the crap out of me so I would at least crack a cover and take a peek

16VGTIDave said:

Looks like I blew the engine. I heard a noise and before I could pull off the road the engine cut out with a nasty rattling noise. Now it won't turn over, so I guess the timing chain let go and pistons met valves.

At least I have cell coverage while I wait for a trailer and ride home...

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Awww sorry to hear that, do you still have the Maxim engine?...
At least you could still ride whilst rebuilding the Seca one.

.....maybe the double downshift you mentioned earlier was too much for the engine...

spectra said:

You will probably start tonight though I know it would be bugging the crap out of me so I would at least crack a cover and take a peek

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Well, I just got home and grabbed a quick bite to eat, and it is now technically morning... But I'm going to grab a couple hours sleep and wait for daylight before I try unloading the bike from my neighbours trailer. It is a tall utility trailer and i'm tired.

Jeff0133 said:

Awww sorry to hear that, do you still have the Maxim engine?...
At least you could still ride whilst rebuilding the Seca one.

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Thanks, yes I still have that engine. But it was getting rather tired and one of the cam lobes was making metal. It will probably provide parts though.

Jeff0133 said:

.....maybe the double downshift you mentioned earlier was too much for the engine...

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Well, that may be a possible cause, though the rev limiter did do it's job. Hard to say at this time.

16VGTIDave said:

Thanks

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16VGTIDave said:

Thanks, yes I still have that engine. But it was getting rather tired and one of the cam lobes was making metal. It will probably provide parts though.

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Take pics, i'd be interested to see the cause and damage caused...maybe make it a thread?

Well, the cause of death was heart failure, as always (that is a coroner's way of saying "They died, stop asking questions"). More specifically, one or more of the cam chain guides failed. This resulted in the cam timing being grossly incorrect. Valves met pistons at 5500 RPM and that was the end of the $50 engine that ran like a top (until 35 year old plastic crumbled). I checked out the original 100K km engine and it failed a leak down test, so there is no point in even trying to run it for a couple months. I'm kinda surprised it was running as well as it was considering it's condition.

I have to admit that while I take pride in my creation and my ability to service it, tune it and repair it, I am tired of the short maintenance intervals and the constant work that it required. I simply ride more than this bike was intended for. And since I commute to earn my living, I need reliable transportation. Time to do some research and consider options.

Not that it will matter at this point but.....a top-end rebuild is not such a big task...just sayin...get the reliable fuel injected pretty face but keep the 400 as a Tinker toy...
Just throwing this at you...