cb 175 cam chain adjustment

Joined: 22 Jul 2006 Posts: 2 Location: indiana

whats the best way to adjust the cam chain on a 72 cb 175? thanks for any help. flathead1

Joined: 13 Jul 2006 Posts: 20 Location: flagstaff

I have a 72 cb175 too. I tried adjusting my cam chain by getting the engine up to running temp and then I loosened the lock nut and then unscrewed the adjusting screw way out. I believe the chain is supposed to self adjust at that point. Then I screwed the adjusting screw back down. That's when I ran into a confusing point because the adjusting screw never tightened, it just got to a point where it kept spinning and not going down anymore. Maybe someone can tell me if I did it wrong, but all the research I found said to do it this way.

Joined: 26 Jul 2004 Posts: 428 Location: Shelton, CT

It sounds like your cam chain adjuster housing has stripped. It's not all that hard to replace but I definitely wouldn't run the engine without an intact adjuster.

Joined: 13 Jul 2006 Posts: 20 Location: flagstaff

Cool, another part to look for! These old bikes are regular money pits. I bet I can score an adjuster housing for pretty cheap though.

Joined: 13 Jul 2006 Posts: 20 Location: flagstaff

Hey ElectroKen,
Do you think I could get away with running a thread chaser through the adjusting hole threads?

Joined: 22 Jul 2006 Posts: 2 Location: indiana

so is this the right way to adjust it with the motor running? thanks flathead1

Joined: 26 Jul 2004 Posts: 428 Location: Shelton, CT

yield27 wrote:

Hey ElectroKen,
Do you think I could get away with running a thread chaser through the adjusting hole threads?

The threads are gone, so there's little left to chase. The housing is aluminum and partial threads just won't cut it. Over-torqueing the old one killed it - easy does it with the new one!

Joined: 26 Jul 2004 Posts: 428 Location: Shelton, CT

flathead1 wrote:

so is this the right way to adjust it with the motor running? thanks flathead1

I don't remember the official Honda procedure for the 175 but if it's similar to the 350 (and it should be) then it's like this:

1) On a COLD engine, remove the four tappet adjuster caps and the stator cover.

2) Turn the crank counterclockwise by the bolt in the middle of the alternator rotor while wiggling each rocker arm to find a spot where all 4 are free (all valves closed). If I remember right for the 175 this will be just after TDC for the left cylinder.

3) Loosen the cam chain adjuster lock nut and then the adjuster. An internal spring does the actual adjusting. Now tighten the adjuster and then the lock nut.

Button 'er up and ride.

Joined: 26 Nov 2005 Posts: 186 Location: Grants Pass, OR

The procedure for my CAM chain adjustment 79 CM185T is slightly different.

Shop manual doesn't mention cold or hot just says stop the engine.

1. Remove the left (stator) cover and turn the cranshaft bolt CCW with a wrench until the T1 mark are lined up with the timing pointer. Note the T1 mark is not the same as the (F1) mark used for engine timing.
2. Loosen the lock nut on the adjuster rod (screw). The internal spring will automatically adjust the chain tension.
3. Hold the rod to prevent it from turning and tighten the locking nut back down.

Kevin

Joined: 13 Jul 2006 Posts: 20 Location: flagstaff

I found an adjustment housing for pretty cheap. When I install it am I going to have to remove the cam chain? Or is there away around that?

Joined: 26 Jul 2004 Posts: 428 Location: Shelton, CT

It just unbolts and comes off the back of the cylinders. It's gasketed, so you'll need to get a new gasket. Don't lose the plunger or spring that comes off with it. The hardest part of the job will be getting any remaining gasket off of the cylinders.

Joined: 13 Jul 2006 Posts: 20 Location: flagstaff

A lot of the threads were still ok so I just got a new longer bolt with more threads and it tightened right up.