Some sad news today 350F

silentsvn

silentsvn

Been Around the Block
This past weekend was out on my CB350F and felt the warming sensation of oil on my left leg this time not like the previous where my left leg got covered in oil due to a blown head gasket. The bike also has a nice plume of white smoke now at high RPMS.

Took the bike home cleaned it all up, ran it and couldn't find the leak, until I noticed the top of the carbs were wet with oil - from the breather is what i'm thinking. There was a small UNI filter I put on it to filter the gasses and critters. I have just also rebuilt the top end which included honing the cylinders, decking the block and surfacing the head, new rings, no valve job since leak test was done prior to the gasket blowing

I just did a compression test - I would have also done a leak down but I don't have a working compressor at the moment.

Here's my numbers:

Dry Test
[list type=decimal]
[*]120
[*]120
[*]120
[*]100
[/list]

Wet Test
[list type=decimal]
[*]145
[*]135
[*]140
[*]100
[/list]

Here are the plugs as well.

GSJLqob.jpg


So.... Is it the valves or rings?
 
I'd say 1-3 are rings, and 4 is either a valve or a demolished ring.
 
How did you do the compression test?
Carbs off? (preferably) or throttle wide open?
How many cycles?

120 isn't really a bad number if its cold.
adjust the valves for cyl 4 and try again
 
Just reread...
Whats your oil level?
If you overfill it can shoot oil out the breather tube.
 
Oil level is good 3/4 up the stick. I was thinking it might be a valve due to the smoking. I have a 4 into 1 so it makes it a bit harder to isolate.

Compression test was WOT with 8 kicks per cylinder. I double checked the #4 and did a dry twice and wet once on it.

I let the bike run for about 10 minutes then ran it up to about 6-7K for a few more before shutting it off.
 
I'm having a fuck of a time adjusting the valves on a CB400F. Damned tiny adjusters. I am going to have to make a specialized tool. I have done it twice, and the tappets still clatter like a skeleton jerking off in a tin cup.
 
Re: Re: Some sad news today 350F

AlphaDogChoppers said:
I'm having a fuck of a time adjusting the valves on a CB400F. Damned tiny adjusters. I am going to have to make a specialized tool. I have done it twice, and the tappets still clatter like a skeleton jerking off in a tin cup.
Click to expand...

Haha I feel your pain - I swear my neighbors think I have Touretes, nope just synching carbs and adjusting valves.
 
AlphaDogChoppers said:
I'm having a fuck of a time adjusting the valves on a CB400F. Damned tiny adjusters. I am going to have to make a specialized tool. I have done it twice, and the tappets still clatter like a skeleton jerking off in a tin cup.
Click to expand...

There is a tool made for this, that allows you loosen the nut, then to turn the screw and keep the nut in the same place, then tighten the nut and keep the screw in the same place. It was at my local shop, but I didn't buy it when I saw it and now wish I had. I'm going back to PHX in 2 weeks or so, and stopping by the shop, and I'll get it and take a photo when I do. Or, of course, you could just make your own... it was basically a flathead screwdriver inside a hollow socket too. It was relatively cheap, though, $20 or so.
 
Yeah, I am gonna have to make a special tool. The adjusters on this bike don't have a slot in them. Just a 3 mm square head. I was using a small tap wrench, but it was a little too clunky. I am going to make such a tool from a socket, and a square head screw.
 
AlphaDogChoppers said:
Yeah, I am gonna have to make a special tool. The adjusters on this bike don't have a slot in them. Just a 3 mm square head. I was using a small tap wrench, but it was a little too clunky. I am going to make such a tool from a socket, and a square head screw.
Click to expand...

Ahh, right. I've got a weird little square shaped wrench that I think came with an old Honda tool kit that fits, but of course does nothing to hold the tightening nut in place. If you do make something, please post a photo. And think about selling 'em!
 
By wet I assume you mean you put oil in the cylinder and rechecked the compression?
If so what does the reading on #4 tell you?
The oil in the cylinder is to see if it is the rings, since no change that tells you it is the valves that are bad.
 
Doesn't everyone have a set of these in their kit?

$(KGrHqV,!n8E8VUzgleUBPJyMjzn+w~~60_12.JPG


http://www.ebay.com/itm/Motion-Pro-Motorcycle-ATV-Tappet-Valve-Adjust-Adjuster-Tool-Set-08-0073-/270904306880
 
I use a craftsman through socket set and a flat head.
Damn things are so tiny though it takes me about 3 tries per valve to get it right
 
surffly said:
By wet I assume you mean you put oil in the cylinder and rechecked the compression?
If so what does the reading on #4 tell you?
Click to expand...

Yes - I first ran the bike to get it warm then, did a compression test which is the "dry" the wet is with 1 teaspoon-ish of oil added to the cylinders to check the rings.

I just re adjusted the valves #4 was super tight both intake and exhaust.

New compression numbers - This is a cold motor with the oil still in from the previous wet test.

[list type=decimal]
[*]130
[*]130
[*]130
[*]120
[/list]

I put her back together and started it up - she still has some white smoke out the exhaust but Im hoping thats just from the new rings, as I was saying before there are less than 150miles on the bike after the top end rebuild. Also oil is good, clean - plugs have been cleaned and re-gapped to .030 and timing rechecked.
 
teazer said:
Doesn't everyone have a set of these in their kit?

$(KGrHqV,!n8E8VUzgleUBPJyMjzn+w~~60_12.JPG


http://www.ebay.com/itm/Motion-Pro-Motorcycle-ATV-Tappet-Valve-Adjust-Adjuster-Tool-Set-08-0073-/270904306880
Click to expand...

Annnnnddddd...... "Buy it now" has been clicked.
 
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