Jammed my engine.

[mmaddix]

So I made a big mistake today that I'm pretty sure jammed my engine. My #2 spark plug hole threads were a little stripped so I went to fix them with a spark plug thread repair kit. I had to tap the hole blew what I thought was all the shavings out then put the new threads in there. Put everything back together and went to crank it. The engine barely moved and then it just wouldn't move anymore. I tried the kick starter and the engine still wouldn't move. I'm thinking there is some metal it there between the piston and cylinder wall

What can I do? I'm probably going to put another engine in my bike if this is going to require disassembly of the engine like I'm thinking.

Please help.

[GLoweVA]

At a minimum, the head may have to come off to look into that cylinder.
Something you could try, at the timing plate, rotate the engine in the reverse direction, that may at least free up that 'debris' that may be stopping that piston. Then you could at least look thru the spark plug hole and maybe spot something. JAT. Hope your piston/cylinder wall isn't too bad off.

[GRom4232]

Once, I was doing a valve adjustment without the tool, which had me taking off the cam shafts to get at the shims. When I was done, after putting everything back together, I tried to fire up the engine, and it wouldn't crank. I thought I buggered the reassembly, ending up with a head-full of bent valves. Long story short, it turned out to be a drained battery. My advice--before taking out the engine, check for battery juice.

[BA80]

You would have to have something fairly large and hard to stop the piston from going up. A few shavings from an aluminum head would be a non issue.

[GLoweVA]

Try pulling all the plugs out and seeing if it'll move then.
Maybe your starter and kickstarter can't overcome the compression.
JAT.

[LoHo]

It would take more than shavings...I had a screw from the stop switch assembly find its way into #3 and the bike ran great, except for the ticking sound in...#3.

[mack]

What else

were you doing to the bike before it got hard to turn over? Not to be too simplistic but are you sure it's not in gear. Pull the plugs and it should turn over if you have a green light.

[mmaddix]

If it was the battery I could use the kick starter to turn the engine over. Before this problem happened I started the bike and let it warm up. I used the colortune spark plug on #1 cylinder and started the bike again. Adjusted the fuel air mixture. Then moved on to. #2. I know the threads were messed up and I already had the repair kit. So I fixed it. I put the spark plug in just to try to start it before I used there colortune spark plug and that's when the problem happened. I'm about to remover all the spark plugs and try to turn it over. I will keep you posted.

Yes its in neutral and I tried it in gear with the clutch pulled in.

[mmaddix]

I moved the engine backwards with the timing cover thing in the left cover and it moves extreamly easy then stops again. Pretty sure i bent a valve with the tap. I should of made sure the valves were closed before i started. Here are pictures. The front of the bike is on the left back on the right.

This picture is of the valve stopping the piston from going all the way up.



Here is one from where the engine stops rotating when i make it go backwards.



Here is one from the half way point of when the engine stops rotating forward and rotating back.

[mack]

.Valve

yes that valve is in the wrong spot. You'll need to pull the head now and replace that one. Pulling the head is very easy and quick if you follow the book to the letter. Somebody on your base will have a compression tool so you can remove the valve. Finding a valve may be a problem though. Best check them all when you have the head off.

[mmaddix]

I have 2 other engines. I could use one of those valves. Our even heads. But I've been wanting to put this 1980 special engine in this bike anyways so now I an just going to do that. Can I run the 80 special engine with the 79 carbs. I know I should change the jets but I'm not going to unless I have to. What's different besides the carbs? Will a everything else match up or will I need to replace some connectors.

[DGXSER]

Good news is that the 79 carbs will work just fine on the 80 engine. No need to rejet carbs, they should be jetted for the year of the carbs, not the engine anyway. May need some adjustments, definitely a synch.

The 79 and 80 both used the 2H7 TCI with mech timing advance and 1.5 ohm coils. So no need to change any of the timing setup.

You may loose the kickstart using the 80 engine, some of the 80 engines have the internals for the kickstart, just not the shaft that goes through the clutch cover. If you want to keep that, you could pull both clutch covers and swap the parts from your 79 to the 80.

Otherwise, it should be pretty cut and dry swap.

[mmaddix]

Thanks. I already got the old engine out and am changing the kick starter over to the new engine. I'm going to be rebuilding the old engine soon. Thanks for all the great info

[BA80]

That 80 engine won't run as strong as the 79. Also, if your not familiar with the engine your putting in it would be a good idea to go ahead and do the fix on the gears while you have it out. It's a lot easier on the bench than in the bike.


Just sayin'

BTW.....I prefer the older carbs and have run them with great success on both engines.

[crazy steve]

Also, if your not familiar with the engine your putting in it would be a good idea to go ahead and do the fix on the gears while you have it out. It's a lot easier on the bench than in the bike..

Check the valve adjustment while it's out too....