'71 cb175 take 3!

Re: '75 cb550 and '71 cb175 double build!

As for the condensation, this is the general rule for eliminating it......

If short trips are absolutely necessary and not avoidable, then the oil should be changed on a more regular basis. No, the water will never mix with the oil, they should have taught you that in middle school. ;)

The preferred method is to simply let the bike run longer. Take the "long way" to the store, let it warm up for longer in the driveway, or quit being a bitch and go for a ride! JK on the last one, I realize you can't always get out and ride. But the important part is to make sure the engine gets hot enough for long enough that the condensation evaporates out of the engine. During summer, this takes about 20 minutes of riding. In colder months it takes 30-45 minutes to get hot enough to evaporate the condensation. No matter what, find a way to control, it will rust your engine from the inside out.

If you are shaking down the motor in the shop, then either don't run it long enough for condensation to start (less than 3 minutes about) or let it run for longer. Tho, keep in mind, if it is a fresh rebuild with new piston rings, the absolute LAST thing you want to do is leave the engine idling in the driveway. This promotes cylinder glazing and prevents the rings from seating properly, and can ruin your motor before you even go for an actual ride.
 
Re: '75 cb550 and '71 cb175 double build!

High On Octane said:
As for the condensation, this is the general rule for eliminating it......

If short trips are absolutely necessary and not avoidable, then the oil should be changed on a more regular basis. No, the water will never mix with the oil, they should have taught you that in middle school. ;)

The preferred method is to simply let the bike run longer. Take the "long way" to the store, let it warm up for longer in the driveway, or quit being a bitch and go for a ride! JK on the last one, I realize you can't always get out and ride. But the important part is to make sure the engine gets hot enough for long enough that the condensation evaporates out of the engine. During summer, this takes about 20 minutes of riding. In colder months it takes 30-45 minutes to get hot enough to evaporate the condensation. No matter what, find a way to control, it will rust your engine from the inside out.

If you are shaking down the motor in the shop, then either don't run it long enough for condensation to start (less than 3 minutes about) or let it run for longer. Tho, keep in mind, if it is a fresh rebuild with new piston rings, the absolute LAST thing you want to do is leave the engine idling in the driveway. This promotes cylinder glazing and prevents the rings from seating properly, and can ruin your motor before you even go for an actual ride.
Click to expand...

Thank you for the input. I have been doing exactly what you said not to do. that being said. I will remedy today. I already drained the oil, have to replace the stator side gasket, then will change with fresh. Question, is there a minimum temperature for Permatex #2 to seal properly? its cold and shit here and I think that may have been a reason why it didnt seal in the first place. That and there may have been a little oil left on the surface. will clean with carb cleaner before i apply it this time.
 
'75 cb550 and '71 cb175 double build!

High On Octane said:
As for the condensation, this is the general rule for eliminating it......

If short trips are absolutely necessary and not avoidable, then the oil should be changed on a more regular basis. No, the water will never mix with the oil, they should have taught you that in middle school. ;)

The preferred method is to simply let the bike run longer. Take the "long way" to the store, let it warm up for longer in the driveway, or quit being a bitch and go for a ride! JK on the last one, I realize you can't always get out and ride. But the important part is to make sure the engine gets hot enough for long enough that the condensation evaporates out of the engine. During summer, this takes about 20 minutes of riding. In colder months it takes 30-45 minutes to get hot enough to evaporate the condensation. No matter what, find a way to control, it will rust your engine from the inside out.

If you are shaking down the motor in the shop, then either don't run it long enough for condensation to start (less than 3 minutes about) or let it run for longer. Tho, keep in mind, if it is a fresh rebuild with new piston rings, the absolute LAST thing you want to do is leave the engine idling in the driveway. This promotes cylinder glazing and prevents the rings from seating properly, and can ruin your motor before you even go for an actual ride.
Click to expand...

Sorry dude but the motion of the oil in your engine is a little different than the oil and vinegar mixed together sitting on your kitchen table. Get enough friction and movement, and they will mix. Albeit for a period of time. Hence my question.

The better way to phrase it is that oil and water won't immediately mix.

If you want to get into the chemistry of it (which they also taught me in middle school), water is a polar molecule which means it can form hydrogen bonds with other polar molecules. Oil is not. However if you create an emulsion through vigorous molecular interaction they will intermingle for a much longer period of time, creating your swirled white fluid in your oil, if we are assuming that it is water.

So you've created a phase change somehow. You've done your own form of titration and out comes a gloopy white solid from your condensation. Seems to me like you just mixed oil and water, High On Octane.

I digress.

Jag, your copper is amazing!
 
Re: '75 cb550 and '71 cb175 double build!


High On Octane said:
As for the condensation, this is the general rule for eliminating it......

If short trips are absolutely necessary and not avoidable, then the oil should be changed on a more regular basis. No, the water will never mix with the oil, they should have taught you that in middle school. ;)

The preferred method is to simply let the bike run longer. Take the "long way" to the store, let it warm up for longer in the driveway, or quit being a bitch and go for a ride! JK on the last one, I realize you can't always get out and ride. But the important part is to make sure the engine gets hot enough for long enough that the condensation evaporates out of the engine. During summer, this takes about 20 minutes of riding. In colder months it takes 30-45 minutes to get hot enough to evaporate the condensation. No matter what, find a way to control, it will rust your engine from the inside out.

If you are shaking down the motor in the shop, then either don't run it long enough for condensation to start (less than 3 minutes about) or let it run for longer. Tho, keep in mind, if it is a fresh rebuild with new piston rings, the absolute LAST thing you want to do is leave the engine idling in the driveway. This promotes cylinder glazing and prevents the rings from seating properly, and can ruin your motor before you even go for an actual ride.
Click to expand...

Good note that it's seasonal. I'm sure it's geographic too. Freaking humidity.
 
Re: '75 cb550 and '71 cb175 double build!

I wasn't trying to get into chemistry debates, I was just simply trying to say that once condensation is in your oil, the only way to remove it is to change the oil or get the engine hot enough to evaporate it. Basically, if you have foamy white/greenish shit in your oil on a regular basis, you need to change your riding style. Plain and simple.

As far as seasonal and geographical, yes, I had much bigger problems with condensation in Wisconsin than I do here in Colorado. With low humidity and warmer temps (for the most part) I hardly ever get condensation now.

Something else you can try, that I do on every ride, is gear down a gear until the motor has come up to temp. This will warm the engine up faster and speed up cooking out the moisture. You sacrifice a couple mpgs, but it's worth it in the long run.
 
Re: '75 cb550 and '71 cb175 double build!


High On Octane said:
I wasn't trying to get into chemistry debates, I was just simply trying to say that once condensation is in your oil, the only way to remove it is to change the oil or get the engine hot enough to evaporate it. Basically, if you have foamy white/greenish shit in your oil on a regular basis, you need to change your riding style. Plain and simple.

As far as seasonal and geographical, yes, I had much bigger problems with condensation in Wisconsin than I do here in Colorado. With low humidity and warmer temps (for the most part) I hardly ever get condensation now.

Something else you can try, that I do on every ride, is gear down a gear until the motor has come up to temp. This will warm the engine up faster and speed up cooking out the moisture. You sacrifice a couple mpgs, but it's worth it in the long run.
Click to expand...

Also a good call. It's tough during break in and first rides if you're a weekend warrior I suppose as well.
 
Re: '75 cb550 and '71 cb175 double build!

Thanks guys. The guy that plated it really did a shitty job, a ton of greyish black crud i had to scotch brite then sand off, then buff the shit outta it.

It's hard to tell in the picture but that's a whole new tail section. should be cool when its done.

I'm looking for a motor to build a frame around also, open to suggestions. I'm looking to do something extreme. i was actually looking into getting a radial 2 stroke engine and doing something crazy.
 
Re: '75 cb550 and '71 cb175 double build!

I was just looking at those pics again and thought "Oh the days of pushing a bike up and down stairs!" Fuck I'm glad I haven't had to do that lately. I think the last time was when I was in my 20's and I had to push my 1980 XR80 up frozen wood steps to get it into my apartment for a top end and carb rebuild. Still not sure how I didn't die, as getting back down I just hopped on and rode it while working the rear brake! ;D These days I don't think my back would even let me try.
 
Re: '75 cb550 and '71 cb175 double build!

High On Octane said:
I was just looking at those pics again and thought "Oh the days of pushing a bike up and down stairs!" Fuck I'm glad I haven't had to do that lately. I think the last time was when I was in my 20's and I had to push my 1980 XR80 up frozen wood steps to get it into my apartment for a top end and carb rebuild. Still not sure how I didn't die, as getting back down I just hopped on and rode it while working the rear brake! ;D These days I don't think my back would even let me try.
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Haha yeah we are in a basement for the time being. Not sure its exactly safe with all the metal work but oh well!
 
Re: '75 cb550 and '71 cb175 double build!

Alright, after some slow paced rebuilding the stator side is completely Re assembled. With any luck it's my only problem, but I will get some riding in next week drop the oil and find out
 
Re: '75 cb550 and '71 cb175 double build!

Question, what would change between cold and warm idle? Bike idles perfect cold, but warm it floats a 700 rpm range. Also while riding when I come to a stop it'll sometimes go to stall on me unless I give a little throttle. Only happens on a warm engine it's just fine cold. Perhaps a carb adjustment or timing issue? I'm far from proficient at tuning just yet.
 
Re: '75 cb550 and '71 cb175 double build!

jag767 said:
Question, what would change between cold and warm idle? Bike idles perfect cold, but warm it floats a 700 rpm range. Also while riding when I come to a stop it'll sometimes go to stall on me unless I give a little throttle. Only happens on a warm engine it's just fine cold. Perhaps a carb adjustment or timing issue? I'm far from proficient at tuning just yet.
Click to expand...

I have a similar situation but exactly reversed - higher idle when warm. I'd like to know that answer as well.
 
Re: '75 cb550 and '71 cb175 double build!

1sttimer said:
I have a similar situation but exactly reversed - higher idle when warm. I'd like to know that answer as well.
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Yes its higher when warm as well. cold I am at 1500 on the dot. warm it will go to 22-2500 down to 1700 and bounce. I think its the same issue. Your's stall at all also?

Im glad you responded since I know you have the probe unit also.
 
Re: '75 cb550 and '71 cb175 double build!

Sounds like your pilot circuit is too rich. RPM should increase when warm, but only about 500 RPMs. Also, 1500 for cold idle sounds a little too high to me.
 
Re: '75 cb550 and '71 cb175 double build!

Went for a nice ride today around 30-40 miles. Other than needing to tune that idle a little the ride was awesome. Suspension felt good, motor functioned well, didn't really go over 60 but hey its a 175 I wasn't planning on it anyways.
 
Re: '75 cb550 and '71 cb175 double build!


jag767 said:
Went for a nice ride today around 30-40 miles. Other than needing to tune that idle a little the ride was awesome. Suspension felt good, motor functioned well, didn't really go over 60 but hey its a 175 I wasn't planning on it anyways.
Click to expand...

Sweet!!!

Are to charging?
 
Re: '75 cb550 and '71 cb175 double build!

Alright, adjusted the air screw setting which greatly improved throttle response, but I still have this Damn idle issue. The only thing I haven't played with are the needle settings. Is it even worth it? I have read that it really doesn't change idle, but I am at a loss. It's not like I can't get a good idle at all. Cold it's awesome, so I do think it's something that can be resolved in the carbs. Any ideas?
 
Re: '75 cb550 and '71 cb175 double build!

Well here's an strange update.

So out of curiosity I rechecked the compression. 130. And there's my issue. So last night the engine came out, and I tore into it. Now I was told the motor had never been messed with. HA! What a lump of crap. First thing I notice is all the gaksets, no adhesive on them. They literally were just kind of there, and we're so hardened I thought they were metal for a second. Next thing to jump out was the big Ole .25 on both pistons. So my conclusion is someone in the past rebuilt at least the top end of the motor.

Here's my question, can poorly sealing gaskets, including the head gasket, cause that low of compression and a shitty idle?

I know it can cause issues, but we're talking like -50 psi compression and a motor that's hard to kick over, with an erratic idle, that stalls within a minute. The pistons and rings look like maybe there's 500 miles on them, so the only thing I haven't measured up is the valves, which if I can avoid taking apart I'd like to.

I'm taking it to have helicoils put in for the spark plugs today, and was going to do a 1 mm overbore as well as have it decked. Now I'm thinking just do the helicoils and put it back together properly.

Thoughts?
 
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