holy you know what..dodged a bullet

[Iahawk]

Have planned on replacing the cam chain tensioner spring on my 84 Nighthawk 650 since I bought it almost 3 years ago.. It's a common issue where the spring gets weak with age and the cam chain starts slapping around at lower rpm.

Started yesterday with the disassembly...side panels, seat and tank. Then off came the coils, plug wires and finally the cam cover.

Today I pulled the oil tubes, cam holders, cams and the cam chain tensioner.

[Iahawk]

I took my time, thought about every move before I acted...read and re-read the service manual.

 The biggest thing to watch out for was dropping the little cotter type pin (?) when separating the chain guide from the chain tensioner. I put shop towels completely around the tensioner and guide...there was nowhere for a dropped pin to go...I thought.

The ONE place I didn't cover was the little gap between the chain and the guide. I carefully removed the first pin and boom...it flipped up and disappeared between the chain and guide. I stared in disbelief. My stomach sank. I thought crap, I just ruined this motor.

Luckily I had been squeezing the chain and guide together below where I was removing the pin from, just to keep a solid hold on it. I looked down there with a flashlight and could barely see the top of the pin..held there tenuously between chain and guide. Had I let go of the pliers the pin would have dropped down into the engine. I tried to grab it with a magnetic pickup tool but it is not magnetic!

I yelled for my daughter for help but she couldn't hear me...my phone was just out of reach. (note to self, always keep phone within reach when working in garage). I finally was able to finally pull my phone close, called my daughter and she came to lend a hand.

She held the light and I was able to squeeze lower on where I was squeezing the chain and guide together..exposing the top of the pin. I used a scratch awl to stab at it and pull it out after about 10 tries.

I was much more careful removing the 2nd, lower pin. This let me remove the tensioner to replace with the new spring. That's as far as I got. Gotta know when to walk away.  I will start reassembly tomorrow. I experienced both full on panic and complete relief today.

pics of the cams, etc., the chain and guide (between these is where I dropped the pin) and finally, the offending damn, little pin. Can't think of the correct name for the stupid little aluminum cotter or holder pin.

[randyo]

coulda been worse, a circlip

[Ruffus]

.hawk, I'm with you feeling panic crawling up the spine seeing the pin taking off.

For such delicate snippets I use a small "needlenose fix grip" plier. Ask me WHY.

I rather destroy or pinch a cent piece than to dive into engine bowels for such reason.
A bunch of cable ties is always close by too.

[Iahawk]

thought I'd follow up on this post with what happened after...

Had a heck of a time getting the sprockets with their timing marks , cams, chain, etc. lined up correctly to put the motor back together.  First try didn't go well...pulled it all back apart to start again...which also meant pulling lifters to bleed them each time the cams are removed.

2nd time was bad...I thought it was correct but motor had loud ticking, which I lied to myself saying it was just a lifter that needed to pump back up. Went for a very short ride and bike wouldn't rev over 4500 or 5000 rpm and had no power. Return to garage and pull everything back apart for the 3rd time.

I was off a tooth or 2 on the sprocket. Ugh.

3rd time starting over...followed service manual exactly (except for a major error in the Clymer manual which had to do with initial rotational direction of motor to line up cam sprocket bolts..) Got TDC on the crank bolt and cam sprocket marks lined up with head, chain on and success!

Put motor back together for 3rd time, overcame a bad spark plug hole thread....and finally took bike out for first ride on Wednesday. Nice 20 mile ride with no cam chain slapping noise like I'd lived with for the past 3 years.

Rode again yesterday for another hour covering about 20 miles in town. Only 3rd (?) ride on the nighthawk this entire season. I'll try to make up for lost time this Fall.

I will say that my Nighthawk is my all time favorite bike. The combination of comfortable ride, riding position, power, handling and looks is a winner in my book.   Will attach a few pics of the process as it seems pics from earlier this summer are lost in the forum.

[Ruffus]

Congrats, looks good??My marking method is kind of similar, with different colored cable clips to disguish certain construction groups.
Anyway, it runs like new and it was for sure worth the effort.

[Stig / Major Tom]

Glad it worked out for you Hawk.
Regarding your previous photos - I do not know what happened during the forum rebuild.
I've learned that some forums can capture the photo in a manner where it is not lost in the future - (the Vespa forum) by that I mean that I've lost a great many older photos when the photo hosting I was using changed something major, and / or closed entirely.


Stig