HELP!!! ENGINE CLANKING NOISE!!

Hey guys I'm brand new to the forums as I recently bought an 86 maxim xj700. Love this bike, but there's suddenly a loud violent clanking noise in the upper left part of the engine. I rode for about thirty minutes across town earlier this morning and then parked the bike for a few hours, no problems, then I started it up again and this loud clanking noise came from the engine! From what I've been reading it might be a valve or lifter or timing problem or something. Any info? Plz help =( thanks guys.

 

Is the noise consistant or does it come and go away with engine rpm? Stock exhaust is known to crack and cause noise , it will come and go depending on engine rpm. Major engine problems generally don't cone suddenly unless you were running high rpm. It is possible though. My first thought is exhaust or cam chain noise.

 

I don't think its exhaust issues because its coming from top end. I removed the plugs and when i turn the crank it comes to an abrupt stop. could it be that a valve is hitting the piston? Seems like clanking is coming from left piston. The hatchmark for the timing is not there. I can see a screw hole nwhere it goes. How can i tell if its a valve crashing? What else coul it be?

 

Sorry, I just realized I didn't answer your question. It is consistant with rpm.

 

You should actually be able to SEE in there (thru the plug 'ole) with a flashlight and careful positioning.

You can pop the valve cover and see if a valve is not coming back up; maybe you broke a valve spring.

DON'T run the motor any more until you figure it out; not even as a diagnostic aid.

This is an "airhead" XJ, not a watercooled "X" right?

 

Correct. This is an airhead. Thanks for the advice. I won't run it. I'm going to pop the cover now. I'll update to let you know what I find.

 

I don't konw how to tell if there is anything wrong under the valve cover. I did find a problem in the first left cylinder. There is a piece of metal (looks like a centameter long piece of a screw. Hard to tell what it is cuz it's all banged up. the top of the piston is damaged. I'm trying to fish out the debris right now. What can it be?

 

Well that sounds like the head needs to come off.

 

besides the exhaust pipes is there anything else I have to remove?

 

You should be able to pull the head off while the engine is in the frame. Take a few pictures as you go, it will help when it goes back togeather. You might want to pick up a service manual and read up before you undo the cams.

 

do you know how i can find any step by step on it here or anywhere else. I know I need a manual but i don't have one at the moment.

 

http://www.yamahapubs.com/index.do

1985 XJ700N Service Manual LIT-11616-XJ-72 $93.00

 

just downloaded a manual (pdf). Gonna try to remove the head tonight.

 

Sounds like screw from carb shaft came loose pull the carbs I wouldnt pull the engine apart unless the valves were damaged . hook up an air hose and pressure up the cylinder and see if you have blow by

 

I just read your post. Too late. I already removed the head--not without some blood sweat and tears. The valves appear to be okay. There is damage to the piston surface and combustion chamber. There are some pretty deep gouges. I'll attach some pics shortly.

 

here are some pics of the damage. Looks like a bolt was in there. Is that possible?

 

tried unsuccessfully to attach pics.

 

Did you figure out where the screw came from

 

I hope it's nothin' real bad.
Let's see!

:::: "Oh, Magic 8-Ball is 86maximusXJ700 going to be OK? ::::

:::: [ Torque Wrenching Time Ahead] ::::

There you have it!

 

No. has perplexed.

 

Has me perplexed. Where could it have come from?

 

Can I use a rotary tool to smooth out the gouges?

 

Gotta be at work early tomorrow so gonna have to continue this tomorrow evening. I truly appreciate everyone's input.

 

Youve taken it down this far might as well keep going you will want to hone the cylinder a small pit here and there wont hurt but if it were me at this point i would get the best parts i could find to use

 

Unless you own a bank, put it back together and see if it will run and ride.

 

Thats real good advice BillB.

The thing is if the cylinder is damaged and the ring's/ piston is not sealing the bike will burn oil and run on three cylinders. So how much fun would it be to "ride the crap out of that"?

Lets see if he can send some pictures of what happened and we can go from there. I'm thinking a carb butterfly screw came out and caused this.

 

I agree we need some pictures of the damage.

Resize pics to 500X500 to attach, or set up a PhotoBucket account and "imbed" them.

The primary concern at this point would be any damage to the cylinder walls or serious piston damage. Let's see what it is we're talking about.

 

Do a Compression Test of the Hole.
See what that tells you.

 

He already pulled the head. Can't do a compression test now.

 

All good advice.

 

Obviously BillB has a problem with other members trying to help 86maximusXJ700 with his problem.

 

if it runs ride it

 

This fellow needs help to get his bike up and running again. The head is off and the piston is damaged and possible cylinder may be damaged also. Unless you have the pictures or some inside information none of us have seen here yet please share it with us OR..........
Please keep your 2 cents it has no "worth" here in this tech forum.

 

There is a LOT more to the value of a motorcycle (well some motorcycles anyway) than simply the "blue book" value.

A lot of us invest or have invested WAY more than "what the bike is worth." TO OTHERS. A motorcycle often has a worth way beyond simply dollars (and sense) to its owner.

In this case, until better evaluations have been made, it might not be necessary to replace the whole motor. Repairing one damaged "pot" IS quite often feasible both from a mechanical and fiduciary standpoint.

We need to see some photos of the damage.

 

Fitz,
Well said my point exactly. Its really the owners decision to do what ever he wants reguardless of what you think Bill.

This is a tech forum and one thing that brings people to this sight is information and not a bunch of hogwash about nothing that does not relate to the problem presented to us.

 

put it back together and ride it !!!

 

I'm in total agreement with everybody who says to get all the intel before making a decision about what to do.

I distinctly remember being a boy, standing in the Shop, with everybody standing-around listening to a horrendous knock that was coming from an Engine.

As some of the younger guys poured-over the situation, doing some listening and Plug-wire pulling to get a better idea about what-was-what, ... my Uncle handed me a Coke and said a few words I remember to this day.

"Hear that knocking? It ain't opportunity."
"That's what Bad News sounds like."

Whatever the outcome of the damage assessment, ... remember one thing.
Don't let your emotions rule how you go about getting the Bike fixed.

Bikes ain't covered under your Health Insurance.
And, no matter how we feel about the Bike, ...
Not one of us has ever heard our Bikes say:

"I love you too!"

 

Gee it looks like BillB has gone back and edited all of his posts on this thread. I guess he figured out that kind of BS was not welcome here.

Back to our regularly scheduled program.

Hope to see some pictures soon.

MN

 

MN,

If you don't believe in my advice you can disregard it.

I hope to see some pictures too, of him riding his motorcycle.

BTW, its year around motorcycle riding weather where I live.

 

lol

 

The point being, unless it's put back together correctly you won't be riding it for long.

I don't know about you, but I build my motorcycles to RIDE. Not sell, not cafe race 5 miles to the bar and 5 back, not tool around town and magnetize babes, RIDE. As in 120+ mile daily commuting, 400+ mile weekend trips. Ride.

You can't do that unless you do things right, not slam bang throw it back together and see how far you get before it 'frags. Trust me it won't be all that far.

This is the guy's ride, not a disposable cellphone fer chrissakes.

86maximusXJ700, the damage could be critical, or it could just look a lot worse than it is, in terms of functionality.

That's why we really need some pictures. (Thanks, MN.)

 

If the head is peppered and the valve seats are ok he could just get it surfaced and put it back on. I'm more concerned about the piston and cylinder condition.

I had one that the screw got jammed between the piston and cylinder wall and It always used oil and never ran right. There was a groove in the cylinder and it killed the rings after awhile.

 

If the scratches aren't to deep it is possible to hone the cylinder but I'm not sure how much you can take off the cylinder. But I'm with Fitz on this one it doesn't made if you ride it 5 mile a day or 500 miles do it right.

 

I bet its not that bad. I cant wait to see a picture.

 

EDZACHARY. That's why we need to see the damage, in order to make educated and experienced recommendations. Let's see some pics, and maybe we can get Wiz to have a looky and give us his input as well.

If it's just the top of the piston and the chamber itself, it's quite possibly not fatal. I've seen cylinders that survived a broken valve and went on to race another day, even with some serious looking dings in the piston crown.

We gotta SEE it...

 

How long did you drive it after the noise started?

 

Now that is a fair question.
One of the engines we tore down once upon a time had a perfect imprint of a screw in the piston dome and the cylinder head wall. The screw was small enough that it passed out of the exhaust before doing any further harm. (thank heaven for small miracles). I've also seen chewed up aluminum head/piston mash, never a pretty sight.
A photo is definitely called for here. Let's hope it is clear and sharp.
I'm keepin my fingers crossed for the easy fix.

 

Some Engine problems place you at the BOTTOM of an INVERTED PYRAMID.

The damage isn't too severe.

But: Replacing just the Piston will start you heading toward the TOP of the "Inverted Pyramid"

Piston
Rings
Remove Block
Lower Gasket set
Wrist Pin Clips
Honing
Maybe needing a cut
Oversized Piston and Rings
New Rings for the Job because "You're there"
The Job grows and the expenses add up because you only need something else!

 

Rick, is it possible to just replace JUST the rings?... ( and the gaskets that go along with that job )