The Saga Continues. (Loooooooong post.) :o)

Alright, I finally went out to the garage yesterday and refilled the XJ700 with oil. I couldn't ride since it was raining pretty hard but I thought I'd fire her up just for fun.

Crank, crank, crank. Crank, crank, crank. Crank, crank, crank. Nothing.

Now, I should probably give a bit of background info that I neglected in my "Oil In the Gas" thread. When I got the bike home from the PO and backed it off of the trailer I put it on the kickstand and cleaned up the puddle of gas that had collected under the airbox vent tube. Being excited about the bike, and not wanting to have to push it up my sloped driveway, I decided to start it and ride it up to the garage. So I hopped on and, out of habit from my Honda CB175 25 years ago, put up the kickstand (Yes, the PO had told me that the kickstand must be down to start it. Old habits die hard. ) and started cranking. And cranking. And cranking. It was only after the battery began to run down that I remembered about the kickstand having to be down. So I put it down and starting cranking again. With the same lack of result. At this point I figured that I must have flooded it and pushed it up the driveway thinking that if I let it sit for a few hours it might start.

That evening I went out and took a shot at starting 'er up again. A couple of cranks and she started. Yeah! Except that I could hear a rather loud knocking/rattling that sounds like it is coming from cylinder #3. The engine revs fine and sounds good aside from this knocking. Now the couple that I bought the bike from were really great and spent quite a bit of time with me going over the bike and, of course, starting 'er up for me. When the wife started the bike (It was hers.) it started immediately and I know for certain that it did not make this knocking sound then. I most definitely would have heard it and asked about it. I emailed them and asked what they thought of this the husband conjectured that some raw gas made its way into the cylinder, resulting in "hydrolock". I wasn't too sure about this but thought that if there was some raw gas in the cylinder that it would increase the compression and could cause premature ignition in that cylinder, thus knocking. He also said that I probably had gas in the oil and that I should change the oil and filter.

The next day I received an email from him and he said that a guy at work had told him that all of the gas going through the engine had removed the lubrication and that I should put some Marvel Mystery Oil in the gas tank and run the engine for a bit to get some lubrication in there. This should end the knocking.

A few days later I discovered this forum and inquired about the gas in the oil situation.

Back to last evening.

So I added an ounce of Marvel Mystery oil to the gas tank. After significant cranking, no starting, and seeing that the headlights have gotten rather dim, it was obvious that the battery was nearly drained. So I pulled out one of those portable batteries with the air compressor, inverter, and jumper cables to attempt to jump start the bike. The clamps were too big to clamp on properly so I sort of held them in place while cranking the starter. It was an improvement, but still no start.

Now I pulled out the battery charger. I've used it before to both charge and jump start cars/vans/trucks and it works great. At 55amps, though, there was no way I was going to try the jump start setting, so I hooked up the battery at the standard 12v 10A setting. A glance at the charger shows 10A amps flowing. A glance back at the bike shows . . . SMOKE!!!

Yes, there was smoke coming up from between the front of the battery and the air inlet. So I frantically yanked off the leads to the charger and cursed myself. I NOW decide to get out the manual for the charger where, of course, it specifically states, "Do not charge lawnmowers, snowmobiles, motorcycles, . . . (You get the idea.) on the 10A setting . . ." So, I put the charger on the 2A setting, hook it up to the battery, and watch for smoke. Fortunately it just sat there, presumably charging. I checked back periodically to check for flames, but all I saw was a steady decline in the charge rate, indicating that the battery was charging, so I hoped for the best.

While the battery was charging I did a search in here for info on charging batteries and found one about jumping a motorcycle battery using a car where RickCoMatic stated that a motorcycle's electronics are rated to handle no more than 15A, beyond that you could fry the bikes electronics. Why then couldn't it handle the chargers 10A? No idea. But the smoke had left me wondering about the state of the bike's electronics.

Before my wife and I went to bed, I went out to check on the bike. The battery wasn't quite done charging, but I knew that if I didn't at least try to start the bike I wasn't going to sleep very well, thinking that I had fried it. Off comes the battery charger, key on, kill switch to ON, choke on, kickstand down, throttle back a bit, and as soon as I touched the starter, VROOOOM!!! Okay, I can sleep peacefully knowing that at least the bike still runs. But . . .

There is still the issue of the knocking. It sounded even louder last night, but I am attributing that to the fact that it is in the garage now, whereas it was outside last time I started it. Now I didn't run it long enough for the gas with the Marvel Mystery Oil in it to make its way through the carbs and into the engine to lubricate whatever supposedly needs lubing, but I'm not certain that I should. I keep thinking back to the "hydrolock" conclusion of the PO and wondering if in fact that was the case and that something is now bent in cylinder #3. If that is the case, then I don't want to run the engine an more until that is fixed. By someone far more automotively inclined than myself.

Soooooo. Assuming that you have actually persevered and read this far, I'm hoping that you can provide some insight into this "knocking" situation and how I should proceed from here.

As always, I appreciate any suggestions you can offer. (Other than to not post anything this long ever again.) :roll:



Edit: It was suggested in my last thread that I post a pic of the bike. Here is one from the eBay listing I bought her from.

 

Does it knock at any RPM?

 

I had almost the same problem (drained 5qts of gas and oil from the PO) but didn't try to burn up the bike.

Once I changed the oil and filter and then put in a new set of plugs, the knocking went away after about 10 minutes. Hopefully you'll have the same luck!

 

The knocking is continuous from idle to whatever rpm ya cranck 'er up to. But your question made me think of something. I don't recall the frequency of the knocking increasing as the rpm increases. I'm going to have to check on that.


Edit: I just checked and the frequency of the knocking increases as the engine rpm increases. I may have to describe the noise as more of a rattling than a knocking. Also, the idle rpm, which I've read should be about 1000 rpm, struggles to stay at about 500.

 

Before you have a heart attack check the easy stuff:

Make sure the collars that hold the downpipes to the head are tight.

Look for anything else that might be loose.

If nothing found you need to pinpoint the noise. Top of engine or bottom of engine? Does it go away in gear?

Oil in the gas is a crock. Hopefully you didn't put enough in to foul the plugs, otherwise should do no harm. The oiling system on the bike will quickly re-oil anything that got the oil washed off by the extra gasoline.

 

Okay, I just did a little experiment. With the engine running, I disconnected the cable to plug #3. Zero change. I reconnected #3 and disconnected #4. There was a noticeable drop in rpm. Reconnected #4 and disconnected #1. Same result as with #4. Reconnected #4 and disconnected #2. The engine had a fit, shuttering and nearly stopping. Reconnected #2 and things improved.

The rattling continued the entire time, but it would appear that cylinder #3 isn't firing. Could it be something as simple as a fouled plug? Would that cause the knocking/rattling sound? I should be so lucky.

 

Could very well be a fouled plug by that description. Before you take anything apart or delve deeper get a brand new set of plugs for a small fistfull of dollars.

Start up the bike and see how it goes. If you still have a problem with knocking/rattling after going through some of the previous steps it is either going to be an electrical problem, a TCI problem, or something related.

Quite unlikely that it is a mechanical problem such as valve, piston, rings and the like. It could be but I would suggest that would be a last resort.

Before I replaced my piston rings my plugs fouled easily and repeatedly. When they were on the way out and one might be more badly fouled than the rest I would get strange knocking noises from the engine. One cylinder fighting against the rest.

Try it and let us know.

 

Next test, remove the vacuum hose from your petcock and plug it. Plug the nipple on the back of the petcock as well. Now put the petcock into prime position, start bike and see if #3 fires. If it fires with the vacuum plugged then it is most likely a blown vacuum diaphragm in the petcock, $20 fix. My '82 was like this when i bought it. I plugged the vacuum and ran it on prime for about 2 weeks till i got the replacement parts. cruzerjd

 

Take the Plugs out of 3 and 4 ... swap them and run it.

If the problem goes away ... throw a set of Brand New Spark Plugs in the bike.
There's no reason to run anything better then Champion RN9YC's.
Iridium is ... You-ridding-money.

If the Plugs do the trick ... Tweak it until you can actually ColorTune it.

Since you have the Marvel Mystery Oil ... "RickCoMatic Stuff" the YICS Passage with COTTON clothes line -- or -- COTTON T-Shirt and individually TWEAK each carb.

Tweak the Pilot Mixture Screw OUT ... until performance deteriorates and it starts missing and backfiring.
Then, TWEAK it IN ... Until performance returns.
Adjust the Idle Rod to maintain 980 - 1050 rpm's

Tweak 2, 3 and 4.

Remove the stuffing.
You gotta be feeling better about thing NOW!

 

Might wait to colortune until after the Marvel Mystery Oil Gasoline cocktail has all been used.

 

I switched plugs 3 and 4 and, while the rattling noise continued, the wire pulling experiment revealed that cylinder 3 was now firing and 4 was not. Switching plugs 4 and 1 had the same result.

So now I'm off to get a new set of plugs. What should the gap be?

 

32-thousandths.

I run Champions ... but, I mess with them, because I'm Old and think it matters.

Before I gap the plug ... I put it in the vice and run an Ignition Points File across the Side Electrode.
Then, I put a quick 600, 800, 1000 surface on it.
Then I gap it and center it over the center electrode.

This is a total waste of time ... because they work fine right out-of-the-box!

This I only do because ... sometimes I ride my bike like I'm a talking Beagle with a vivid imagination, having some great fun, flying my doghouse.

 

You are a FUNNY guy!
I was literally Laughing Out Loud when I read that one!!!

Keep it up!!!

 

Now I feel old reading that. How many folks do you think still can recall the reference? God rest you Charles Schultz.

 

Okay. I've replaced the plugs and, while it definitely runs better, it is still making the knocking/rattling noise.

Again, I am far from what I would even call competent when it comes to anything automotive, but is it possible that this is simply a timing issue? That is, is it possible, with all of the bouncing around in the back of the U-Haul trailer, that the timing simply got knocked out of whack and that this is causing premature ignition? Keep in mind that this was not a trailer for hauling vehicles, just your standard U-Haul trailer, and the bike bounced so much that the kickstand dented the floor of the trailer.

I'm just grasping at straws here as I am *really* frustrated. The bike ran perfectly when I picked it up from the PO.

Thanks.

 

Doubtful.
Highly unlikely.
Darn near impossible.

Read PM.

 

Highly doubtful the timing has been shaken out of alignment. It's solid state and relies upon a reluctor plate bolted on the end of the crankshaft, ergo it isn't going anywhere.
Have you performed a compression test on your engine yet? If so, what were the numbers?
When I get a knocking/rattling sound out of my beast, it usually indicates a low idle. Where does it idle now? 950-1050 RPM is the range your aiming for.

 

Check for "Knuckle-head Knocks" too ...

Tank securing bolt loose.
Broken exhaust collector mount ... forward of the center stand.
Loose Spark Plug.
Loose exhaust header pipe collars
Loose engine mounting bolts
Missing EGA Port Bolts
Worn through or missing fuel tank rubber shock mount
Broken stock brazed-on exhaust clamps
Hidden speaker near bike and somebody messing with you!!!

 

UPDATE: Just in the event that anyone is interested.

Having returned from vacation, I was preparing yesterday, mentally at least, to measure the valve clearances to see if that was the cause of the knocking/rattling.

Just before leaving I had run the bike a bit on the centerstand and noticed that it sounded just the slightest bit better. Knowing that, for me, measuring valve clearances was going to be an extended project, I decided that, shims be damned, I was going to take this bike for a ride. So I started 'er up to let get warm while I tried to get the seat back on. (I'm sure it's just me, but I have a difficult time getting the "tongue" in the back of my seat to go into its slot. The tongue is a bit chewed up.)

As I'm busy twisting and shoving and yanking the seat, I noticed that the idle was slowly working its way up from the 500 rpm that its been at since I brought the bike home. I also noticed that the bike was sounding significantly better. By the time I had the seat on, the bike was purring along at 1000 rpm and the knocking/rattling had disappeared!

This would seem to coincide with about the time it would have taken to burn through the gas that had been in the bowls and to get to the stuff from the tank that had the Marvel Mystery Oil in it. So it seems as though the friend of the PO may have been correct after all. Maybe not. I don't know. What I do know is that the bike runs like a gem now.

So I took 'er out to a local gas station to fill up the tank. Wow! It sure ain't the Honda CB175 from my teen years. Now I can't wait for my riding gear to arrive so I can go for an extended ride.

Thanks to everyone for all of the help and suggestions.

Now I just need to measure my alternator brushes. :wink:

 

Marvel Mystery Oil is something I NEVER run-out of!

I have a Trigger-operated Oil Can loaded with the stuff.

It's THE ONLY Product I ever squirt into the Carbs of a running engine.

If you KNOW you are going to be riding Long and Hard, in fast-moving Interstate Highway Traffic ... bring the Marvel along for the ride!

When you fill-up ... add 3 Cap-fulls to a Gallon and go-ahead and gidd-ee-yapp!

Marvel Mystery Oil's "Claim to fame" is that it's a "Top Cylinder Lubricant"
It provides extra protection to the rings ... especially at 5,000 rpm's and above.

It works too break-down Carbon Deposits on the Combustion Chamber and the slopes of your Exhaust Valves.

It adds some protection to the Exhaust Valve Stems when they open and the super-heated exhaust gas passes over them.

"Marvel Mystery Oil can be added to gas or oil. It combats internal motor rust and corrosion, lubricates valves, piston rings, upper cylinder walls, and eliminates valve sticking. Keeps rings free and reduces piston and cylinder wear. Also keeps fuel pump and carburetor parts clean, eliminating the need for frequent adjusting. Marvel Mystery Oil retards formation of power dissipating motor deposits, such as gums, varnish, and sludge. The Standard for break-in on new or overhauled engines."*

*Manufacturer's Statement