Motor spun fine on bench, now in frame won't kick

That's how it was when I put the cam in the first time on the bench. TDC was lined in the rotor and cam perfect I've done that before I'm familiar with it. However now I can't get the rotor to TDC because it's at the "frozen" state. Is my cam chain stretched to bad? It's damn tight with the adjuster. Not to loose without it. Still hard to pull the chain off with both side cam bearings out lol.
 
xjwmx said:
In your very first picture...I've never seen a rotor like that but the timing mark on the stator is lined up with a part number on the rotor, not the rotors timing mark. So -- line up TDC mark on rotor with TDC mark on stator. Then make the cam sprocket so the mark is as straight up as can be, and without letting the rotor move. Then you should be good..
Click to expand...
I did that the first time. Set the marks up perfect. The only way to spin the rotor is if I take the cam bearings off and have someone hold the end of the cam And then I spin. Once the cam bearings go on and the chain gets tighter it freezes. Old chain but doesn't seem loose
 
I had an engine that would slip timing. Set it up correctly, kick it a couple of times and then she'd seize. Reset it, kick a couple of times and seize. I pulled the sump plate and saw there were some teeth ground down on the crank cam gear. Not saying that's what you have, but something to check.

If the engine was working fine before the front guide was put in it .............is it possible to put the guide in upside down? lol
 
Last edited:
It is possible to put the guide on the head upside down, but then the guide hangs too far diwn, and no way can you get the head to seat that way. Are you sure its straight in the chain tunnel?
 
Jake, nice pics. Let's look closer.

So, it looks like the crank is jammed at about 20°-30° BTDC. The cam is about 10°-15° BTDC. At half rotational speed, that looks right. 20° at the crank equals one tooth of the cam sprocket. So, I'd say the cam timing is right.
JakeV-01.jpg


Now we're entering the 'twilight zone'.

At 20° BTDC, the pistons still have about 2.5mm - 3mm of upward travel before they reach the top. With the camcover off, and the camchain loose enuff, the head/cylinder group can be nudged upward, possibly without being noticed.

Looking into the left cylinder's plug hole, you can see the piston top, and its direction arrow.
JakeV-Lcyl.jpg


Looking into the right cylinder's plug hole, .....well, I'm not sure what's going on in there. Some sorta markings?
JakeV-Rcyl.jpg


So, I'm thinking along the lines of some sort of foreign object in one of the cylinders, randomly bouncing around, then suddenly getting into just the right position to jam between a piston's crown and combustion chamber. Loosening the camchain allows the head/cyl to nudge upward slightly, giving the impression of being freed.

Maybe you could peek into the plug holes, see whut's in there, maybe pluck something out.

Better if the head is pulled, the piston tops examined, and the valves checked for seating/sealing and/or bent...
 
TwoManyXS1Bs said:
Jake, nice pics. Let's look closer.

So, it looks like the crank is jammed at about 20°-30° BTDC. The cam is about 10°-15° BTDC. At half rotational speed, that looks right. 20° at the crank equals one tooth of the cam sprocket. So, I'd say the cam timing is right.
View attachment 99507

Now we're entering the 'twilight zone'.

At 20° BTDC, the pistons still have about 2.5mm - 3mm of upward travel before they reach the top. With the camcover off, and the camchain loose enuff, the head/cylinder group can be nudged upward, possibly without being noticed.

Looking into the left cylinder's plug hole, you can see the piston top, and its direction arrow.
View attachment 99508

Looking into the right cylinder's plug hole, .....well, I'm not sure what's going on in there. Some sorta markings?View attachment 99509

So, I'm thinking along the lines of some sort of foreign object in one of the cylinders, randomly bouncing around, then suddenly getting into just the right position to jam between a piston's crown and combustion chamber. Loosening the camchain allows the head/cyl to nudge upward slightly, giving the impression of being freed.

Maybe you could peek into the plug holes, see whut's in there, maybe pluck something out.

Better if the head is pulled, the piston tops examined, and the valves checked for seating/sealing and/or bent...
Click to expand...
I'll check it out as soon as I get time. Thanks. And those markings on the pistons, the first pic is an arrow on it. The second, that's carbon , they're not brand new pistons.
 
Looking again at those piston tops in the plug holes. They'd have to come up another 2.5mm - 3mm to get to TDC. They already look high enuff to be at TDC. If so, maybe the rotor is mispositioned on the crank (missing woodruff key?), and the cam is indeed retarded, and valve strike is happening...
 
TwoManyXS1Bs said:
Looking again at those piston tops in the plug holes. They'd have to come up another 2.5mm - 3mm to get to TDC. They already look high enuff to be at TDC. If so, maybe the rotor is mispositioned on the crank (missing woodruff key?), and the cam is indeed retarded, and valve strike is happening...
Click to expand...

Problem is the way he is reporting this the "locking up" happens with the rocker arms not even on the head. So valves and cam timing would not have any bearing on it.

I'm thinking there is something real wrong either with the way the engine is assembled or the way the problem is being described.
 
Jake have you tried turning the engine over with the cam chain tensioner removed, and all bearings on the cam shaft? Similar to what 2M said.
I'm thinking your cam chain tension is set WAY to tight, or like 2M said, there is something inside of the combustion chamber preventing the pistons from reach in TDC.
Slow down and listen to the guys on the web here.
Take the cam chain tensioner out and turn the motor over, bet it turns over all the way.
Report back.
 
B Burdine97 said:
Jake have you tried turning the engine over with the cam chain tensioner removed, and all bearings on the cam shaft? Similar to what 2M said.
I'm thinking your cam chain tension is set WAY to tight, or like 2M said, there is something inside of the combustion chamber preventing the pistons from reach in TDC.
Slow down and listen to the guys on the web here.
Take the cam chain tensioner out and turn the motor over, bet it turns over all the way.
Report back.
Click to expand...
Sadly with it out it does the same thing. The pistons are going up to the exact line inside as they were before I took the motor apart
 
Jake Violando said:
Nothing ever goes right for me. Now o can't get the head off to inspect the valves. No matter how much I beat it. Maybe I used to much gasket adhesive
Click to expand...

You have removed all the bolts? Bolts near spark plug?
If you can't get the head off, make sure all the bolts are out, nuts off, cam out and lift the cylinder/head off as one piece.
Something is wrong.
 
don't forget that tiny bolt in the head back by the cam chain adjuster ! and the ones by the spark plug....
a light pry with a screwdriver between the head and the cylinder fins may be needed to break the bond of the gasket goop... notice I said LIGHT PRY as the fins can and will snap off !!!! if you start ronching on it with a crow bar to pry the head and cylinder apart you will break something !!!!!
good luck.....
bob............
 

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