Topic: cb750 cam chain guide Q?

[Don R]

 I got a new one and noticed the ridge in the middle. I always wondered on used ones how much of that was wear.
  I do seem to have a totally smooth one with no wear or ridge, I'm wondering if that was a PO modification or if there were some made with no center ridge? 

[PeWe]

Here photos of 3.
2 later taller with ridge. One in unopened Honda bag, 14611-300-000

And an earlier shorter rattling in cylinder model with no ridge.
Only some chain marks. But it look like as it might have had a ridge that has been worn flat. Or chain scuff marks only.

When using the taller one. Verify it will fully enter the heads tunnel.
I had to grind on the left side where it stopped. Not all the way up needed.
Irritating when assembly the head.

The shorter has thinner pin that sit loose in cylinder grooves. Can cause a rattling sound. Nothing I have heard, a friend noticed me about it.

[Don R]

 I've come across the early one with the shorter bottom. I appreciate the pictures, when I am out there next I'll compare what I have.

[HondaMan]

There were a bunch of aftermarket ones made (I think by Tourmaster) that lacked the center ridge. They keep showing up, sometimes in Honda-like bags. Those are leftovers from the spate of counterfeit Honda parts we experienced in about 2008-1010 or so. They also have some confused partnumbers: the K0 and Old Factory K1 engines had the short one, which came back in the K7/8 engines (and is sometimes found in F2/3 engines that had it changed by someone, due to an error in the Honda Parts Fiche circa 1990s). In the K7/8 heads the head casting has an obstruction against the tip of the longer one, which I have (on several occasions) filed away (with a large cold drink and a fan on summer days...) in order to use the longer guide. It makes the chain last longer and run quieter if you install it in those later engines.

I have also seen the short ones installed upside down in K1-K6 and F0/1 engines (and they will fit)! I guess the one they took out was the full-length version and the new one wasn't, and the owner wanted the lower length to guide the chain at its bottom end? Or something? It worked, though.

Today, in Honda's abbreviated parts fiche, they show only the short one. I prefer to use the full-length one as it makes the cam chain run quieter: I get them at PartsNmore.

[BenelliSEI]

Gentlemen.... Very timely discussion! I just placed an order with Honda Canada for cam tensioner, roller wheel, and the knock pins I need for my S/C project. They don’t have the cam chain guide 14611-312-000. Vintage cb750.com shows one (see picture) but it might be the one Mark is referring to? What do you suggest I order and from where? Thanks! John D.

[denward17]

I recently got a cam chain guide from Kelowna powersports:
https://www.kelownapowersports.com/
In BC...

[BenelliSEI]

I recently got a cam chain guide from Kelowna powersports:
https://www.kelownapowersports.com/
In BC...

Thanks! Is it smooth or ribbed?

[denward17]

ribbed...

[Don R]

 I pulled the cylinder off the stroker motor and it had a short one in it. The Hot Rod 836 didn't have one at all, the one with the part number bag is a new one from JT Marks daughter.  It was $30.10 delivered.
 It seems the smooth ones are the short ones at least in my collection.
 The stroker motor is F1 based.

[Don R]

Gentlemen.... Very timely discussion! I just placed an order with Honda Canada for cam tensioner, roller wheel, and the knock pins I need for my S/C project. They don’t have the cam chain guide 14611-312-000. Vintage cb750.com shows one (see picture) but it might be the one Mark is referring to? What do you suggest I order and from where? Thanks! John D.

You need the one that doesn't have a tail below the pin area, the early cases don't have room for the tail. It appears it's the short-smooth one.

[BenelliSEI]

Thanks all. Don’s right, my original is very short. Vintagecb750.com indicate theirs is for early motors. I’ll order one to compare......

[Don R]

 I see they have both types and their shorty is also smooth.

[BenelliSEI]

I see they have both types and their shorty is also smooth.

Right. I’ll get the shorty and compare to what I pulled out. It actually has a crack, half way through the boss portion, for the lower pin.

[newday777]

David Silver shows they have 10 in stock

https://www.davidsilverspares.com/parts/by-part-number/partnumber_25687/

[Don R]

 For anyone missing the slide out pin I noticed vintage cb750 also has those. 

[HondaMan]

For anyone missing the slide out pin I noticed vintage cb750 also has those. 

I also have a couple of those pins, if they are out of stock.

[PeWe]

That pin can be a std size of "steering pin" lock things in correct place when bolted together ?