Loose cam?

[jrwox]

Hey everyone! Sure enjoy reading about these wonderful motorcycles here!!
I bought a '82 GW in very good shape for $500 last fall. The guy I bought it from said he was going to install new timing belts but they were too long and now it wouldn't start.(oh boy...)But, for $500, I thought it was still a good deal so I bought it. I'm finally getting to it as we had a VERY long spring here in Minnesota(matched a record number of days before reaching first 60 degree day). It's finally riding time!!! I got the parts all together, timing belts, new idlers, thermostat, and radiator hoses, so I took took it apart. When I got in there and put it on TDC, I noticed the left timing mark was right on but the right was 3 notches off(!!!). When I took the belts off the left was tight without play but the right had a lot of play. I can turn it about a 1/4 turn with no drag whatsoever. I timed everything just the same and, after turning the engine over a few times with a wrench and having no resistance, tried it out. It started right up but had a popping sound on occasion from the right side. It sounds, to me, like I have bent valves as it can't be normal to have that much free play with the timing gear. One thing about GW, the heads sure don't look like they're too much of a problem to take off! I'm wondering what my next step should be. Should I have Honda replace the valves? Is there a head gasket kit for one bank with head gasket and seals? Should I replace the head bolts with new due to stretch? The timing consuming part is removing all the stuff just to get there! Thanks for any advice in advance!!

 

[joedrum]

it could very well be free play in the cams on one side and then the other at different positions im not convinced any thing broke yet or bent .....I woulnt run it till I knew ....compression test could be done ....leak down test on intakes with plugs out ...lots of things ....if valves bent its most likely intake valves

 

[dan filipi]

1/4 rotation on the cam does seem to indicate bent valve to me.

Have you adjusted the valves?
A very loose one will answer the question.

 

[jrwox]

I need to buy a compression tester today to see what's going on. No, I haven't adjust the valves yet.

 

[dan filipi]

I need to buy a compression tester today to see what's going on. No, I haven't adjust the valves yet.

I would save the bucks on the compression tester til after adjusting the valves.
You'll know right away if a tappet is real loose and has to be turned way in if that valve is bent.

 

[jrwox]

I just went out and took a better look. The cam gear turns only about an eighth, not a quarter, of a turn but there's about 1/16" of clearance between the front most intake valve and the rocker. Not a good sign. The adjusting screw and lock nut are tight so it didn't back off. I'm going to pull the head and find a good used one to put on. I wish people would not attempt something unless they know what they're doing! Are there any head gaskets that are junk or are they all pretty good on ebay. I know on Subarus it's very important to get a good gasket because there's lots that are junk. Also, should I buy new head bolts or are they okay to reuse? I really appreciate the help!!

 

[mcgovern61]

There are junk head gaskets out there. I would only use OEM. The bolts should be fine.

 

[dan filipi]

Agreed.

Some of us here are up for trying the aftermarket head gaskets and taking a chance on them but for the long haul your best bet is OEM.

 

[joedrum]

yeap bent ...that's conformation ....head gaskets ? ....just make sure there not 1000 gaskets ...they will blow in 1100s ....ive seen this a lot ...1100s with blown 1000 head gaskets ....pistons in 1000 are smaller enough for failure big time

 

[jrwox]

I took the head off and found both intakes bent. I searched the forum on here and found partsandmore.com which has intake valves for $10 each, not bad! I'm going to buy the valve seals for it also. The bike only has 40,000 miles so I didn't plan on replacing the exhaust as they didn't take a hit. I'm going to buy a OEM head gasket also. I don't have a valve spring compressor or I'd take the valves out myself. I need to clean up the surfaces for the new gasket and hope they get here quickly!

 

[joedrum]

don't look bad at all ...sould clean up nice ....take your time cleaning gaskets and don't dig in the head ....use lots of touch ...its a heck of a lot more important than Honda gaskets to do this right

 

[flash2002]

This is what I made to take the valves out. Just cut a slot in a pipe to fit the top of the spring, then I use a C clamp to compress the spring and tweeser to take the clips out.

 

[dan filipi]

Hey there ya go :good:

 

[slabghost]

Looks like this is handled already. Bent valves or not I'd be checking the cam pulley key is in place and undamaged.

 

[jrwox]

Thanks for the cheap valve spring compressor idea! I think I'll weld a washer on the top for the c-clamp to set on. I'll just have to make one today and get those valves out.
I'm hoping that the valve guides are okay. That has to be a lot of pressure on them when something like this happens. I'll check for bell mouthing and cracks. Otherwise, I think I'll be okay once the parts start coming in and will be on the road in the not too distant future.

 

[jrwox]

I am having problems with timing. I bought all the parts to repair the bent intake valves and installed new seals. I put a new head gasket in, the head on and torqued. Everything was going good until I re installed the timing belt and attempted to turn over the motor by hand. I went half a turn until TDC came up again and the intake on the number 1 cylinder starts to open right before the piston reaches TDC and the intake valve hits the piston! I adjusted the valve clearance .004 beforehand on 1 and 3. I checked the key way because of the pressure it took to bend two valves and it's good. I just don't understand it! The flywheel is on "T", the left side is right on it's timing mark, and the right side that I repaired is right on it's mark too. Both camshaft gears are in the "Up" position as stamped on them. There is no problem turning over the left side when I have the timing belt off the right side and all valves seated. Any advice would be very much appreciated. I must be missing something!

 

[mcgovern61]

The one thing you are missing is the camshaft takes two turns for every single turn on the crank. Rotate the crank again to T1 and see if that helps.

 

[joedrum]

okay ...hmmmm ...these dang pullies have a lot of mark on them ....sounds like your doing it right ..check to make sure your using right mark there is video of all the pullies and marks ....cant be anything to big ...if I were you id sink all the rocker adjusters in the rockers and snug lock nut to keep them from falling ou this will make it easier to get belt timed right ....see if that helps a post back

 

[dan filipi]

mcgovern61 » Tue May 21, 2013 11:55 am[/url]":24gq542q]The one thing you are missing is the camshaft takes two turns for every single turn on the crank. Rotate the crank again to T1 and see if that helps.

I've never found which revolution to T to make a difference since T is one complete rotation of the crankshaft, each time it comes around.
It's the cams that rotate 1/2 speed but as long as "UP" is UP and flywheel is on T then the cams and crank will be synced.

Now if the flywheel were gear or chain driven at 1/2 speed then it would make a difference but the flywheel is solidly attached to the crankshaft, running at a 1 to 1 ratio.

As for the interference your feeling, I made a video of the cam gear marks.
It shows the correct and incorrect markings. https://classicgoldwings.com/forum/cgwin ... ming_belts
I'd start there to verify and loosen the valve adjusters completely and try rotating. Maybe something else is interfering?
A guy not too long ago found a small washer had dropped in through a spark plug hole so consider the unusual as possibilities.

 

[jrwox]

Thanks for the replies! I took a look at the videos. I'll go over it tomorrow as I need to get to work. I agree, it can't be anything too bad. I'll write when I know more.