Can Anyone Help with This???

[macmac]

Yes Tomm and I are on the problem, and since this is my first time to read I see the cam guide rail might well be broken in TWO. Do not run this engine again!!!!!!!!!

Tomm if you can find the busted off end with just a light if no other way is possible thru the plug well or the tensioner hole say so. I have no idea when I will be on line again , but you can call.

Also drain the cooling system if you want.... rad drain is easy, the lowest bolt on the water pump too. If you don't feel like 'I / We' will.

I will not be running that engine when I get there to just hear it anyway. This will take more than 16 hours probably. That means since Gwyn and I will be there to get some hot dogs and beans,,,,,,,, don't for get I like La Batts either!

My best guess with out looking is the chain did jump, and now the guide rail is busted as well. Don't worry.... I can get this fixed, but I don't know how long in time it will take. Looks like I may have to come and go more than one trip, mainly to discover everything, then come back once the parts come in. Call any time...

sent a pm too...

[macmac]

Originally Posted by trosco

I'd say that you broke the front cylinder tensioner when trying to force the install. So the front cylinder tensioner puts no tension on the cam chain. Now when you start the motor and while it is runing the noise is that cam chain whacking the spark plug housing and the reason you have no power is the cam timing is off on that front cylinder. The puffs of outbound air at the throttle body is your intake valve still being open when the compression stroke starts. If you haven't already bent a valve keep running the motor and things will get far enough out of time that you'll snap a valve or punch a hole in that front piston. Don't know where you got your compression specs but 50-85 psi is not right for a healthy cylinder either,

His de-comp valve isn't working..... Ck the book on these (AKCV) and Hell NO I had no idea what a AKCV was either! (Automatic Kawasaki (de-)Compression Valve) Comp is around 80 psi at under 360 RPM, or cranking speed.

Do you know for sure if these engine can crash? I can not determine if they can or not. Not all engines with over head cams can crash, but a good many can. I don't know if this one can, or not.

I am dead sure this engine should not be run again, untill it is timed and the guide rail is fixed if it has a sharp ragged top edge thru the tensioner hole.

[krash]

Mac the Nomad Doc is on the case..... and he makes house calls

Glad to have you back on the forum Doctor Mac

[Top Cat]

I know if I lived anywhere close to Mac he would be doing all my mechanical and electrical work.

[cnc]

Would be nice if one could borrow an optic fiber camera to put down the spark plug hole and inspect for signs of the valve hitting the piston.

[MAS Tequila]

Let me know what parts you need. I probably have them laying around.

If the KACR isn't functing, DO NOT turn that motor over. The KACR's have a funny habit of coming apart like a hand grenade. I've seen heads with extra holes in them from these useless pieces.

When you put the engine back together just leave them out.

They actually function by causing the rear of the cam to rise slightly thus not letting the cylinder get a full charge until the engine is spinning over circa 750 rpm.

MT

[tomm]

Well, it's been a while due to some medical issues, but things are finally starting to move forward here again. Mac and Gwyn arrived yesterday evening (real pleasure to meet them both) and today we start working on the bike.

Definitely looks like the timing chain jumped, so first step will be to pull the engine. Then take it from there. I'm just hoping the tensioner guide rail isn't damaged as well as the timing being off, and that no other damage was done in the short time that I had the engine running.

Either way, I'll know for sure shortly.

[ringadingh]

If the chain jumped, I hope it didn't cause the valves to hit the piston, that can get costly.

[tomm]

Pulled the engine yesterday, removed the front rocker cover and rocker head, and checked the valve timing. Sure enough, it had jumped several teeth. But the good news was that the tensioner and guide looked fine. What was most surprising was how easy it was to re-time it. Once the tensioner was out, it was really easy to just lift the chain off the gear, re-time everything, and put the chain back on. There is that much slack once the tensioner is out. Mac was surprised as well. He said he's never seen an engine where there wasn't something preventing that.

I needed to order a few more parts (gaskets and o-rings) before we can put it back together again, so ordered those and we'll get back together again in a couple of weeks to finish the job. Working with Mac is super. Even though this is the first Nomad engine he's pulled, he definitely knows his way around motors.

Bottom line - I think we are both a bit surprised that there are not others who have encountered this same problem. If the tensioner is removed when the valves are down and there is a lot of tension on the chain, it could easily slip. Would definitely recommend the extra step when doing cam chain extenders of taking off the left side cover to get at the timing marks, and cranking the engine over by hand until all the valves are closed. Pretty easy to remove the spark plug tube as well to feel the chain and make certain.

Hopefully this will get the bike back in running condition again. I'm sure the rear jug is in good shape, and based on my descriptions, both Mac and I think that there is a high likelihood that there is no damage to the front jug as the bike idled fine even though the timing was off. Just wouldn't run past about 2500 RPM when the timing started to advance. Also, there was no problem turning the engine over by hand. Anyway, we're not planning on pulling the head or doing anything with the rear cylinder.

[Netnorske]

This is good news! That photo of your bike is a little disturbing......but it sounds like you guys will have that thing back in good running order sooner rather than later. Best of luck with the rest of the project....

[macmac]

YUP! I have never seen a cam chain set up like this before. It is very similar to most any other chain set up, but for one fact, and that is the chain can be pinched in fingers and pulled right off the cam gear, when the tension is slacked off.

In this case the cam by chance was set at a point where the valve springs were able to over come the cam lobes and turn the cam, closing the valves 'probably'.

Since the engine had been run before I could see the problem, the above is my best guess.

From this day on, any time I do extenders, I will have the left side engine cover OFF the engine,and turn the engine by hand, so I can see the crank mark.

Leaving the right side plugs IN, with a finger in the left side plug hole for which ever cly you want to do, the compression can be felt, and 'we' would want to.

The crank markings come up correct and incorrect, meaning the cam will not be relaxed off the compression stroke. And 'we' want the cam down, away, off the rockers anytime the tensioner is removed.

[ringadingh]

That sounds positive, if the pistons didn't get hit you should be away to the races.

[macmac]

Ring I hope not, and saw no sign. but the rockers are still off for lack of gaskets.

Also I FUBARED the tensioner spring for my first time and don't understand how...

For the time being the spring was trimmed (shorter) to fit and the tensioner is semi installed. I have in stalled tensioners before and never mashed the cap end of the spring.

[clayton]

Well this makes me nervous :( I am getting close in adding the extenders and I have an 08....
By reading this post it seems this was a freakish event???
Mac, other than dismantling the left engine cover is there any other options that us "not so mechanically inclined" mechanics can do to keep us out of this situation?
I know I might be over worried and for the most part I do my own work on the bike but I certainly do not have a "Mac Mac" around me :) though I wish I did.
Good Job guys

[ponch]

Originally Posted by clayton

Well this makes me nervous :( I am getting close in adding the extenders and I have an 08....
By reading this post it seems this was a freakish event???
Mac, other than dismantling the left engine cover is there any other options that us "not so mechanically inclined" mechanics can do to keep us out of this situation?
I know I might be over worried and for the most part I do my own work on the bike but I certainly do not have a "Mac Mac" around me :) though I wish I did.
Good Job guys

This is one case where the $360 for the GTPP would have paid off.