Since it can't be a bent crank (never got touched). It's gotta be the hub or the bolt not on right.

Strange the bolt or hub isn't straight anymore. This engine never had any real impact except for a broken prop almost a year ago.

Here's the video of the clicking sound: http://tweakshop.net/dl50-click/

It would seem your initial, and hurried assessment of the problem was incomplete, thoroughness and patience are virtuous Padawan.

Well it ran great 2 days ago. Only the last flight I noticed the shaft being out of line and now that clicking sound I did a tedious job putting everything together, cleaning, new header nuts etc. I'll take the prop hub apart and if that doesn't reveal a solution the engine is all yours You have all the parts within reach...

Don't feel to bad, I'm sure you did a good job on what you did, just missed something in the original assessment that wasn't obvious to you. The clicking is most likely a rod bearing. The wrist pin bearing is new so that just leaves the big end. Its possible (likely) that a small piece of the wrist pin bearing cage was missed and left in the engine when repairs were made and has caused damage to the other bearing. Removing the propeller hub without planning a complete disassembly won't tell you much at all.

Thanks for the advise. Then I'll take it apart again. I don't mind the time but I don't have any spare gaskets and there's a chance I won't get the cylinder gasket off in one piece. I'll get some tools now to also disassemble the prop hub. I believe it's 1/2" that I need, 2" in length.

talking about clicking noise...i hear that sound on mine and others gassers....most of the time when the engine is at idle...what part produce that sound?. As i said just at idle.

It's 13mm and a 2" length will work fine. Your biggest obstacle will be to get one with a large enough hole through it to reach the hex and that doesn't need to be turned down to fit between the hex and the hub. Most of the deep sockets have an ID to small for the 10mm propshaft and they won't reach the hex without modification.

The most common reason for the clicking sound is clearance in the wrist pin bearing, it's usually relatively quiet, benign, and normal. The sound that Martin's is making is loud, came on suddenly after a repair, and is a accompanied by a nearly thrown off spinner and an engine suddenly askew in it's mounting. None of these things are good signs on their own but all together at the same time is cause for some.....investigation.

Got the tools. The usual clicking is also related to the piston ring which has some play (that you can feel from the tip of the prop). The clicking of my engine is somewhat loud

A 1/2" (12.7mm) socket seems to fit a little better. OK, here we go again

Martin, on the positive side at least you are learning how to fix these engines. I kind of wish I knew how myself. It certainly makes the repair go faster if I can do it (RIGHT of course) myself. Maybe I should buy a used one that needs work and start learnen !!!!

It sure makes sense that the wrist pin bearing failure could cause more damage in other places....broken pieces all over the engine. Could you have actually broken a crank and hence the wobbly hub?

mstam1971,
Do you own or have access to a dial indicator? After you pull the propdriver you can check the crank for run out. .002 should be the max. The original propdriver on my DL was .0075.[X(]

thanks Jody...i asked for curious cause nobody on the club didnt know why gasser engines makes that click noise when you move the propeller and also at idle.

hey mstam,also ,when you go to remove to prop stud,after you find a deep thin wall socket,,you can move the piston to allmost tdc,the put some oil in the cylinder replace the plug and the piston wont move ,it will be hydraulic ally locked ,this way the load is spread across the piston as opposed to using a piston stop or a piece of plastic in the exhaust,,,if the stud comes off easily ,it may give you an indicator that things were not properly tightened at first,and as you allready know,,if that prop hub has been wiggling ,it need to be replaced.

No I don't.
Got myself a strap wrench but it's not holding up so I'm gonna need to make a metal tool to hold the prop hub. See if I can get a dial indicator. Strange that this issue seems to be new or else I would have had noticed earlier.

The clicking sound is a mystery. There are no metal parts left, bearings look fine, no play and no grinding.

if the strap slips use my method with oil ,but the cylinder needs to be on.

Couldn't the connecting rod be bent using this method?

Greg

yes if its cheap and flimsy,but this is the method used by many enginge repair shops ,you risk bending it if you use a piston stop,or even denting the piston ,or if you put hard plastic in the exhaust ,one could damage even more ,if the bolt dosent give,,a heat gun usually will allow the loctite to let go if it,(the bolt)dosent move easily

Yeah, I don't want to take that risk. I have a bent gear I'll drill some holes in and mount that on the prop hub
Advance Auto Parts didn't have a dial indicator unfortunately. They did have some gasket material so I can cut a new cylinder gasket that I just ripped into pieces.

And I think the clicking sound is coming from the piston hitting the cylinder head. I have a little spot on the piston w/o carbon.

every bodys different,but about this time i would be looking for a box and packing material,to send it in ,but i also understand your desire to fix it yourself for the satisfaction and the time for waiting for shipping,usually a two week turn around for a half hour repair.but in reality ,like youve said ,,they have parts on hand and probably can rule out whats not broken quickly.

Martin, the piston cannot hit the top of the head, it's probably hitting the piece of bearing cage or roller that got left in the engine after the initial repair. You should be able to feel this as you turn the engine over with out the spark plug installed, as the piston comes to TDC you will feel slight resistance then with a little more pressure it will go over TDC. If the crankshaft bearings feel tight, there is no end play in the crankshaft, and there is nothing leaking from the main bearings, you should not need to remove the prop hub or crankshaft. I would carefuly inspect the bearing on the big end of the rod by using some magnification and turning the bearing around the crank throw with a small screw driver through the oil slot in the rod. If anything looks marginal continue with the disassembly.

Get a couple of cheap 5mm bolts and thread them into the prop driver. wedge a screwdriver in there around the socket and break it free or use the strap wrench on the bolts. Again,the reason for removing the propbolt and driver is to see where the wobble is coming from.

Thanks. I still have the prop hub assembly not running in the center so I'll disassemble it.

Will take the plug out and see if it blocks anywhere. What I noticed is that one half of the cylinder head is completely clear from carbon and I have a blank spot on the piston, see image.

I checked the cage roller really well by turning the crank slowly and couldn't find any irregularities. Also the front and rear bearing seem to be in perfect shape.

TBC...

And unit53, yes I could send it in but Jody would have to go through the same procedure and the last missing tool is the piece of metal to hold the prop hub. I always mount my hardware to outlast the frame of the plane and I can do this repair w/o taking the engine from the stands, and taking off the choke and throttle linkages, and I still have the header in place on the cylinder. Messing w/ the header too much can eventually cause it to start leaking, stripped threads etc. Now I only need to replace the cylinder gasket. And I think something is wrong with the prop bolt. I'll find out soon.

Just got myself 4 5x16mm bolts from ACE See if I can manage w/o the metal tool.

This must look familiar to Joe