Topic: PROJECT "JUnK" ISN'T SMOKING ANYMORE !!!

[ProTeal55]

Hey ,

My scoot has always smoked alittle out the right side pipe (when I had the 4 into 2 exhaust), and never really thought anything of it. Now since I put the 4 into 1 on their, the thing is chugging pretty good 

Only does it at idle, and never smokes a bit while under throttle (riding).
Thing runs like a champ, and I can feel the compression when I kick it over.
And when I mean the thing burns oil, I mean the entire inside of my exhaust is covered in it.

So , where do I start ?
I don't wanna pull the head/motor, as if that is needed I will let the bastard smoke all day long.
Anything I can do/check/look at that might solve/fix the issue ? Could it be some wacky carb issue, since I have yet to re-jet/tune/sync them ? I also get wicked blow-by/steam outta my crankcase breather (thought I always have) from day one..
A bottle of motor honey and some 20w-50 oil didn't do the trick, so now I am stumped...

As usuall , all help is very much appreciated.....

[DammitDan]

Valve stem seals.  If it smokes at idle and doesn't get considerably worse under load, your stem seals are going/gone bad.

Be careful how much oil it's drinking...  The stem seals have gone bad on my CB650 and it's taking up about a quart every few hundred miles.

[ProTeal55]

Be careful how much oil it's drinking... The stem seals have gone bad on my CB650 and it's taking up about a quart every few hundred miles.

I always do alittle top-off before and after I ride the thing now, as the last thing I need is a oil starvation issue.

Valve stem seals. If it smokes at idle and doesn't get considerably worse under load, your stem seals are going/gone bad.

This might be a stupid question but how do I go about changing/replacing these seals you speak of ? Is it a motor come outta bike thing ?  Or something I can do in a hour and be on my way ?

[Tim.]

Motor comes out, head comes off.

Don't neglect it.  Last spring I rebuilt my engine (rather, I paid to have it done).  I had the head reconditioned, and I gave them new seals to install.  A while later, the bike started smoking, and it got worse.

Compression check showed lower compression than I should have with new .5mm over pistons etc.  Leakdown test showed I was losing it at the rings.

Pulled the engine apart, and sure enough - valve seals are shot, as are two exhaust guides.  The constant burning of oil causes the cylinders to glaze, reducing the seal for the rings = lower compression.  The compression/leakdown tests of course don't test for valve seal health.

If your seals are gone, pull the engine and replace them.  I'm into an entire rebuild again.  I could likely have simply honed the cylinders again, but then I should use new rings, which are as much / more than a new piston kit which includes rings.  Honing increases clearances, so I'm just starting all over with new pistons/rings/pins and a fresh stock set of cylinders that I'm having bored.  Boring/honing isn't much more than just honing anyhow.

All of this because the idiot who did my valve job didn't put the new seals on a year ago. 

[Ernie]

you need to pull the cylinder head and remove the valve springs then seals, on the 550k it can be done w/engine on the bike ,but i donno about the 750....i think i read you gotta pull it to remove the head

[dusterdude]

can the cam be removed in the bike?if so,you can make a rig to put air in the cylinders and then find a spring compressor that will allow you to remove the springs while in the bike.

[Tim.]

Nope - you can't even remove the valve cover on the 750 without pulling the engine.  Only thing you can do in-frame is adjust tappets through the access holes.

That's what I like about my 550   I had the pistons out of the bike in 2 hours and it was my first time doing it.

[ProTeal55]

Not good news gentelman - not good at all....

[Tim.]

You should be fine for the rest of this season, unless you live in the tropics    Do it this winter.  Take the entire bike apart - you're itching to do it, aren't you    Just think about a freshly powdercoated frame...

[mwohlenhaus]

even checking valve clearance is a #$%* on a 750, with the motor in.  I broke my angle and straight feeler gauges trying to check them.  I don't have alot more riding to do before it is gonna get the big teardown for the winter.  I've got an 836 kit, a big cam, and hopefully if money permits, a little porting and polishing.  but for sure a valve job.

[ProTeal55]

Due to other financial responsibilities (bills-food-women) , I doubt anything will be happening to my bike this winter besides it being put away with a cover on it. Just gonna have to run a thicker oil and see how long it goes before it gets real bad - even though it is pretty bad now..

Just cant afford to tear down, nor do I want to pull the motor outta that bike.
If anyone wants to do it for me cheap (Elcheapo), let me know...

[hcritz]

Hey Teal...
Something to try if it's valve stem seals...
I'm not really big on liquid fixit stuff...but the new "High Milage" oils have a chemical in them that helps soften old rubber parts and is "Supposed" to help older valve stem seals...
I use it in my Volvo...with 239,000 miles...but it never used oil anyway.
I'd make sure that it doesn't have any of the friction modifiers that will cause the clutch to slip...but I don't think that the Castrol 20-50 does.
Won't hurt to give it a try! Only cost a bit more than the regular oil. I'm sure it takes a little while for it to do it's thing, so give it some time.

[putnaja1]

Due to other financial responsibilities (bills-food-women) , I doubt anything will be happening to my bike this winter besides it being put away with a cover on it. Just gonna have to run a thicker oil and see how long it goes before it gets real bad - even though it is pretty bad now..

Just cant afford to tear down, nor do I want to pull the motor outta that bike.
If anyone wants to do it for me cheap (Elcheapo), let me know...

Dude look at the bright side- at least with all the oil going through your exhaust, your don't have to worry about it rusting out!  

[ProTeal55]

Dude look at the bright side- at least with all the oil going through your exhaust, your don't have to worry about it rusting out! 

Funny guy 
I have allready heard this one from my buddies.
As well as :
"Ride in front front of me to kill the bugs before they hit my bike"
"Is that a 2-stroke ?"

 

[MRieck]

All of this because the idiot who did my valve job didn't put the new seals on a year ago. 

Yikes He used the old seals??

[Sam Green Racing]

When we first ran the CR750 It was Smoking on all cylinders and breathing heavy from the cam box and crankcase breathers.
As it wasn't doing it when we bought it as a runner, I asked Chris how much oil had he put in 
Problem solved.

Mike, looks like a head job is needed in Mn

Sam.

[ProTeal55]

When we first ran the CR750 It was Smoking on all cylinders and breathing heavy from the cam box and crankcase breathers.As it wasn't doing it when we bought it as a runner, I asked Chris how much oil had he put in

I dont get it.
Did it have too much oil in it, or none at all ?

[Sam Green Racing]

Too much

[ProTeal55]

So you are saying that if the oiltank is overfilled the bike will puke oil outta the exhaust ?
I thought it would just pump it out the overflow ?

[seaweb11]

"Just cant afford to tear down, nor do I want to pull the motor outta that bike"

Don't cost nothin to take it a part and have a boo inside

Someone else here who has done this repair give him the cost of supplies needed to do it.

[ProTeal55]

And who would this be you speak of ?

[Tim.]

All of this because the idiot who did my valve job didn't put the new seals on a year ago. 

Yikes He used the old seals??

Yep - when the shop that is currently working on the head (www.conceptsonwheels.com) took off the springs, apparantly some of the valves were ready to just drop out under their own weight - nothing 'sealing' at all - seals were falling apart.

I had given the last guy all 8 seals out of my gasket kit to use.  He sure didn't use them.  I should have taken a closer look upon receiving the head back.  Lessons learned.

I'm waiting on my new Honda A & B gasket kits from Western Hills to arrive.  Will be using the seals from the kit, as well as the new Honda guides I've got on order.

Royal pisser this.  So I have my 550F and 750F both sitting in my garage, unable to move.  I'm going to pop the battery into the 750 to see what lights up right/wrong.  Believe it or not, it has what appears to be the original Stanley headlight on it.

[Tim.]

The costs of pulling the engine and taking off the head would be the valve seals being replaced and a new head gasket.  Some say you should replace the base gasket under the cylinders because you've relieved the pressure on it - no opinion on that other than I'd guess 90% of head gaskets get replaced without replacing the base.

You'd also want to replace all the o-rings and other rubber bits you have access too when the head is off / engine out.  Possibly cam chain guides/slippers, cam chain itself, cam chain sprocket...

It can add up.

[ProTeal55]

It can add up.

I know how things add up , thus why I am not pulling the motor.
I am gonna ride the bike the way it is, and if it blows it blows.
Then I will get a 836 crate motor kit from Cycle X in Cheeseland (WI) and call it a day.....

[Tim.]

It can add up.

I know how things add up , thus why I am not pulling the motor.
I am gonna ride the bike the way it is, and if it blows it blows.
Then I will get a 836 crate motor kit from Cycle X in Cheeseland (WI) and call it a day.....

Damn straight.  Mosquitoes be warned!  (from one fogger to another)