[charte]

Hi!

Putting some miles on my 69 now, and more and more, it's getting very hard to start.

Some notes:

*  I don't need to hit the decompression button anymore to turn it over....seems there is lack of compression when it's cold.
*  I have to throttle it to get it started, and catch it just right.  I then crank up the idle screw to keep it running.  As it warms, the idle speeds up and I back down the screw.
*  There is now a loud tapping sound from the engine.
*  When it's on the road, it runs strong.  This has me confused on my compression theory.
*  Checked the ignition, seems ok, plug has no oil buildup.

Going on a trip down Skyline drive in a month, and I'm getting nervous.

I'm hoping for some advice.  Does this series of symptoms indicate something specifically wrong?

Really appreciate any help!!!!

[t120rbullet]

One of your pushrods adjusted  too tight maybe?

[charte]

Interesting, and thus a valve stuck open?

[ace.cafe]

I'd agree to check all the adjustments.

Also it might be a good idea to do a compression test.

[Ice]

 I concur with all of the above.

 A pushrod to tight could hold a valve open enough to lose some compression while cranking.

 In a situation like that ,once running combustion pressure may be forceing a valve close and flex the push rod in the process.

 Higher dynamic compression would make the motor run strong. Too strong and the floating bush takes a beating.

[charte]

Ok guys, thank you very much.  I'll break out my manual and see how to do that.

That seems to fit the symptoms.  Will keep you updated!

[charte]

Hey guys, I don't want to abuse my privelage here, but I can't find my book....how do I go about checking if I have a sticking valve/pushrod?

Is this listed somewhere and I can get a link?

Sorry to expose such ignorance....I've grown accustomed to it ;-)

[Ice]

Checking adjustment id straight forward

Roll your motor over to TDC if there is not enough compression just keep an eye on the ammeter for deflection. ( You could also remove the petrol tank and rocker covers observing the rockers and valves. )

 Remove the tappet cover on the side of the motor. Push rods should spin with thumb pressure but have no up down movement.

 

[charte]

Hi Ice, Ace, T120, and team,

Sorry for the time lag..........been traveling way too much for work.

I followed the procedure you outline above.  I also took the tank off and the valve covers to inspect things.

Sure enough, the intake push rod DOES NOT spin as you describe, and the exhaust does.  Must be nice to have your experience ;-)

I've attached 2 pics....one is the tappets at TDC (defined as when the ammeter pegs left), and the other is on the intake stroke.  It does appear that the intake tappet does not fall as far as the exhaust, so perhaps it is stuck up.

I also can hear air forced through the carb during the compression stroke.

So I think all you guys nailed it.

I'll start playing with adjustments, but frankly I don't know what I'm doing.  Any thoughts are, as always, welcome.

[charte]

Holy you know what Batman!

I found some nice posts about this adjustment, fiddled with it for a while, and wow, I think it solved the problem!

Started up so fast it surprised me.  It actually tried to kickover when I was just fooling with the kickstart.

Let's hope this is it!  I'll put some miles on it and see how it goes.

Thanks y'all!

[baird4444]

    You've done well, Grasshopper....

[charte]

Thanks!  And in the process of this stuff I went from Scooter to Bulleteer ;-)

Just went out to start it.  Fired up on the first kick.  I put the wrenches I used in the toolbox!!!!

[charte]

Hey guys, I thought this was over and done, but it seems there's more going on than I realized.

To recap:  Once again the Enfield community to the rescue......indeed the tappets were out of adjustment and making it hard to start.  The key was adjusting the intake.  As soon as I got that one right, it is fine and easy to start.  Also, the valve tap was coming from the exhause tappet....I tightened that a bit (still spins)  and the tapping went down to what it did originally. 

So, thanks again team!

The problem now is that it still just doesn't have the compression I'd expect.  When kick starting, there is no appreciable difference from using the decompression lever or not.  However, you can certainly hear the difference.  No decompressoin lever = wheezing throught the carb.  Compression lever = wheezing through the exhaust.

But, if it was leaking through the carb, I'd expect a back fire, and not having it start.  Yet it starts and there is no backfiring.

Finally, it does idle roughly, and I notice a significant loss of hp.  Torque seems fine when accelerating and going up hills, but I can't get her past 55mph pegged.......she used to do well over that, probably 70+ (which was scary with tube bias ply tires and drum brakes.

I hope I haven't broken a ring or put a hole in the piston.

Can anyone piece these symptoms together and come up with a theory or have a similiar problem?

[ace.cafe]

If you can verify for a fact that compression is leaking out thru the carb when the decompressor is closed, then you have a bad intake valve/seat.
It needs a valve grind.

If you can verify that it wheezes out the engine breather when the piston goes over TDC on the compression stroke, then you have bad rings. I seriously doubt that you have a hole in the piston if the bike is  running.

Sometimes these sounds can be tricky to identify exactly where they are coming from.
But if you have wheezing out the intake during compression, then the only thing that could be is a bad intake valve or seat or both.

[charte]

Thanks Ace!  Of course took your direction.

I think I have bad news for me.

I assume the breather is the duckbill tube on the left side of the block.  I just held it while kicking it over, and sure enough, air is coming out.  I assume nothing should come out when the engine is cold and I'm just kicking it over.

Is this the kiss of death?  I need new rings?

[ace.cafe]

Thanks Ace!  Of course took your direction.

I think I have bad news for me.

I assume the breather is the duckbill tube on the left side of the block.  I just held it while kicking it over, and sure enough, air is coming out.  I assume nothing should come out when the engine is cold and I'm just kicking it over.

Is this the kiss of death?  I need new rings?

You have to be very careful when assessing that symptom.
Air is going to come out of the breather when the piston is going down, and that is normal.
The thing to listen for is air being pushed OUT the breather when the piston is coming UP on the compression stroke ONLY.
It can fool you because it's tricky if you don't listen to it just right.

Here's something easy to do.
Squirt about 5cc of oil into the cylinder thru the spark plug hole.
Give it a couple minutes to seep down around the rings.
Then kick it over.
If the compression seems to come back  to normal when you do this, then you probably have bad rings.
If it has no effect, then you probably need a valve job.
Either way, the head has to come off, and if you take the head off, you should also pull off the barrel and check the piston and rings anyway.

That's the bottom line.

[charte]

Thanks Ace!  Will do.

I have my 63 Bullet out and getting it ready for Rolling Thunder.  I wanted to use teh 69, but my Dad advised me that if it is a ring, running it will score the cylinder.  Makes sense.

It will take me some time to get to that project.  Will post the results when I do in case others can learn from the findings.

Cheers Ace, thanks for always being there. 

[charte]

Hi!  Sorry all, took a long time to get to this project.  Thought I'd post an update for posterity, and ask a question.

First, the update.........I took the head off.  Before I did that, I measured the compression.....60 psi.  I think that is off by half.

There is a lot of carbon buildup in the chamber.  Incredibly, I have a neighbor who is a motorcycle magician, and I took it to him for advice.  He squirted brake fluid into the intake from the carb side, and it immediately flowed right through the valve.  He did the same from the exhaust side, and it stayed dry.  Bingo, intake valve is not closing tightly. 

He removed the valve, and you can see the carbon buildup on the face and the head surface.

So, we have the culprit. 

My neighbor is going to take care of grinding the valve.  I owe him moy cervesa.

Now the question;  what is the valve guide clearance, and what is the measurement of teh valve stem?

Bullet 500 iron.

Thanks everyone!!!!  Hope you don't have to do this too!!

[ace.cafe]

Valve stems are 11/32" diameter.
Intake guide clearance should  be about .001".
Exhaust guide clearance should be .0025"-.003".

[charte]

Thanks ACE!  Tempting to put in a Fireball while I have this thing cracked open.  However, my drum brakes barely stop me as it is! ;-)

Really appreciate this.

[charte]

Hi all!

Another update for posterity..........want to tie this up for the record in case it helps anyone.

Ace, thanks for the measurements, worked great.

I de-carbonized the piston and area, put the head back on, cranked it all back together per the specs in the manual with a new gasket, changed the oil, filter, and plug.

Compression completely back at 105!!

I started her up.

However, she ran horribly.  I first went through the carb because she'd been laid up for 9 months.  Seemed ok.  We checked the points, and there was some arching.  Changed 'em out.  Still ran rough, though slight improvement.

We scractched our heads for a while, then went for timing.  I read some solid posts here, so I used the tips.  I retarded the timing, and sure enough, it helped a bit.  I retarded it more, and got it to run!  It still kicks every now and then when I decelerate, so I'll probably play with timing more.

So, somehow, fixing the valves and restoring compression no longer worked with the timing setting.

She's back on the road, and I'm a happy guy.

FYI, the thump now is incredible, and back sounding like it should.  Solid compression is a good thing ;-)  Special thanks to my neighbor Tim who did the valve job for a 12 pack (I gave him a case of his fav beer to up the ante), and to my Dad for coaching me through the whole job.

[cochi]

Charte, glad your Bullet is up and running. I had the same problem about two years ago. The guys on this forum were incredible . They diagnosed the problem and also advised  to use a little Sea Foam in the gas. It decreases the carbon build up. It seems to work. I was able to look inside the cylinder through the spark plug hole with a bore light and after 3000 miles  there doesn't seem to be much carbon build up. cochi

[charte]

-Interesting!  Do you use it with every fill up, or or some semi regular basis?

[barenekd]

son't make the assumption that your rings are bad, yet. You will get some air blowing out the duck bill when the position is coming down. Be sure to just push the piston up to TDC while you're listening. Another way to judge ring health is to squirt a little oil in the cylinder and see if the compression rises significantly. If it does you have a ring problem. Do you have a compression gauge? That would help your troubleshooting abilities significantly, too. You apparently do have in intake leak that was caused by the tight valve letting hot gases slip by the valve eroding the edges. Did you do the decoke? If so, then you know the tear down procedure. It takes very little more to pull the jug to check the rings. You can take the rings off the piston and stick them in the cylinder and measure the gap. The service limit gap is about .035". The minimum (new) is about .009"
The max gap between the ring groove and rings .011 for the top ring .015 forthe second ring and .021 for the oil ring. If these are exceeded with new rings, you need a new piston.
Bare

[charte]

Bare, agree, the culprit turned out to be my intake valve/seat.

I think it was never really seated perfectly, we suspect, and as I put on the miles, carbon started to build up in the gaps, and slowly widened the leak.

The valve job and port polishing my friend did put me right back to where the compression should be.

She sounds like a Bullet again ;-)

[barenekd]

You were talking timing problems and you mentioned arcing of the points. Did you change the condensor? If it's bad, your timing will literally jump all over the place. That was a nice thing when the BSA and Triumphs went to timing light timing, you could tell real quick if the condensors were bad. The arcing of the points is about the only clue that the condensor has gone south without the light. If you didn't do so, change it and reset yor timing.
Bare

[charte]

Hey Bare!

Yes, I did the shot gun approach and replaced condensor and points.  So good point, I don't know if the condensor or points change made the difference and got rid of the arching.  I was taught by my Dad always to replace both at the same time as a general practice, so I don't know which part fixed it.

Hey, if you're game, do you have a scientific way to get the timing right?  I"m just doing it by sight and sound.........look for slightly before TDC, set the points, and spin the wheel till it runs well.

On my old cars and my boat, of course I have timing marks, and I can use a timing light, etc.  Is there a method like that to get more precise?

[neil]

Hi Chart:

Just to re-inforce what others have said, I had similar symptoms 3 years ago and it was caused by carbon build-up top side and wear on the valves. I pulled the head, cleaned the carbon and ground the valves and that cured the no compression problem. It had persisted for some amount of time because I was using E-start at the time and starting was ok.. When I pulled everything E-start, the lackof, - - or low compression made it hard to start. After the top side work, all was well.

As an aside, getting the head off was a problem but persistence got it off. Best of luck with your bullet.

Neil and Buzzy.

[charte]

Neil and Buzzy, thanks for the words of encouragement.  I'm not glad you guys had the same problem, but misery loves company ;-) and I know my situation is not unique.

[cochi]

Charte, sorry I took so long in getting back to you regarding the Sea Foam. I use an ounce per gallon every other tank full. It also affords some upper cylinder lubrication. A lot of folks here swear by it and they have made a believer out of me. cochi 

[Ice]

Hi CHarte,

 Another vote for Sea Foam here.  

 First time I did the Sea Foam de-carbon treatment the huge black cloud of carbon coming out the tail pipe scared the daylight out of me !  The improvement in running was immediately apparent afterward.

 Adding it to the fuel tank every other fill up keeps the carbon down.

 About the front brakes.
Higher performance brake shoes are available but costly.
A properly done Hitchcock mod does improve the braking quite a bit.

http://www.hitchcocksmotorcycles.com/pictures/content19/front_brake_overhaul.pdf

[charte]

Cochi and Ice, thanks again for the tip.

Got Sea Foam today and put it in with a new tank of gas.

I just de-carbonized and cleaned the carb, so I might not see dramatic smoke coming out, but from what you describe, it will help prevent build up.

Thanks guys!