Honda CX 500 Forum banner
1 - 14 of 14 Posts

·
Registered
Joined
·
390 Posts
Discussion Starter · #1 · (Edited)
Hello--

So I'm one of those dummys that ordered all the parts for a 650 swap without seeing if the motor is any good lol. Decided to look at the motor today.

I got two GL650 motors for super cheap at an estate sale. One has a broken cam, most likely due to PO trying to get the cover off to do a cam chain replacement. PO then bought the second GL650 motor and never opened it.

I decided to use the second gl650 motor for my swap. Looks good on the outside, must be good on the inside, right?

Popped the oil filter cover off and there was about 1 teaspoons worth of what appeared to be aluminum sludge sitting at the bottom of the filter housing. I had the motor stored leaning on the filter housing, which is why the sludge prolly ended up in there.

Filter looked fine, and I didnt see anything gold in the sludge.

Took the "oil pan" off and it was clean, minus a tiny tiny bit of dirty oil.

Theres still cross hatching in the cylinders when using an endoscope.

Timing chain in this second motor is also shot.

Would the guides from the cx500 work in the GL650? I replaced the chain on my cx500 about 5000 miles ago, and it too has to get opened up to get the output shaft. Prolly going to reuse the 500 chain if I can....#cringe

Would you be concerned about the metallic sludge? I would assume its probably from the chain / chain guides.

One of the pics kinda barely shows the metallic stuff in the oil.
 

Attachments

·
Premium Member
1978 CX500 "The Grub", 1983 GL650I "Nimbus"
Joined
·
12,263 Posts
The 500 and 650 use the same chain. They have different tensioning systems.
The automatic tensioner in the 650 can be replaced by a 500's manual tensioner. It requires a few parts from the 500, plus a specific thread adapter. The manual tensioner will allow you a few more miles on a timing chain before it needs to be replaced.
If the auto tensioner is unbroken, your lightly used 500 chain will work with it.
Be sure to maintain the same orientation when you refit the chain.
 

·
Registered
Joined
·
390 Posts
Discussion Starter · #3 ·
The 500 and 650 use the same chain. They have different tensioning systems.
The automatic tensioner in the 650 can be replaced by a 500's manual tensioner. It requires a few parts from the 500, plus a specific thread adapter. The manual tensioner will allow you a few more miles on a timing chain before it needs to be replaced.
If the auto tensioner is unbroken, your lightly used 500 chain will work with it.
Be sure to maintain the same orientation when you refit the chain.
Will the 500 rear cover work with the 650's ignition system?

I know i need the m6x1-m8x1 threadsert...what other hardware from the 500 do i need to reuse?

Murray mentioned that he thinks the metallic sludge is from the clutch. Seeing as I dont know the mileage of this motor (somewhere between 20-30k since the chain is shot) I am thinking the sludge I saw is normal wear and tear
 

·
Premium Member
1978 CX500 "The Grub", 1983 GL650I "Nimbus"
Joined
·
12,263 Posts
Will the 500 rear cover work with the 650's ignition system?
Good catch. I missed the big item.
It requires a GL500 rear cover, as well.
 

·
Premium Member
1978 CX500 "The Grub", 1983 GL650I "Nimbus"
Joined
·
12,263 Posts
You'll need the tensioner blade and adjustment bolt from the 500. I left the opposite guide in place.
 

·
Registered
Joined
·
24,578 Posts
when you do the swap to the gl500 rear cover you do have to check that the 650 waterpump impeller fits as it is taller and moves a bit more fl;uid around it fit in some of the cover with proper clearance
some it scrapes I always put the rear cover on then fit the impeller and put the water pump cover on with some magic marker on the inner cone of the cover
torque the water pump cover on and then rotate the engine through a few turns
take the cover off and check for any scoring in the cone
some time I use a bit of modeling clay then just press the cover on take it off and measure the clearance
 

·
Super Moderator
'84 CX650E that is evolving into a GL500
Joined
·
18,698 Posts
That was the correct cover (did you buy it or did you miss it?)

Re the water pump, if you use the GL650 impeller make sure you use the 650 water pump cover too.
 

·
Premium Member
1978 CX500 "The Grub", 1983 GL650I "Nimbus"
Joined
·
12,263 Posts
when you do the swap to the gl500 rear cover you do have to check that the 650 waterpump impeller fits as it is taller and moves a bit more fl;uid ...
I used the 650 pump cover with the 500 rear cover and had no issues.
 

·
Registered
Joined
·
390 Posts
Discussion Starter · #11 ·
That was the correct cover (did you buy it or did you miss it?)

Re the water pump, if you use the GL650 impeller make sure you use the 650 water pump cover too.
i bought it lol. it appeared to be in great shape compared to others on ebay, good price, and free shipping. cant beat that!

welp, i guess the build is pushed back until i get that cover and the thread adapter. amazon said for the adapters estimated delivery april 4-14 x_x if it does take that long i may call around and see if i can find one locally.
 

·
Premium Member
1978 CX500 "The Grub", 1983 GL650I "Nimbus"
Joined
·
12,263 Posts
I only found it from that one vendor. Send me a pm. I might have a spare.
 

·
Premium Member
1978 CX500 "The Grub", 1983 GL650I "Nimbus"
Joined
·
12,263 Posts
There's another step I forgot.
The 650 engine has a non-extended tensioner brace, like the pre-recall CX500. Assuming you will be using the 650's chain guide on the left side, you'll need to either cut the extension off a 500 brace, or add a hole to the 650 brace to anchor the tensioner spring. I'm not sure if the spring would interfere with the flywheel using the 650 brace, as I modified the 500 part. Compare the two braces, and you'll see what I mean.
 
  • Like
Reactions: SirFoxx
1 - 14 of 14 Posts
Top