camshaft JD B

[nutsoverJD]

If you have been following my threads. I'm still having a valve timing problem after trying and making adjustments that all of you have offered. One of my original ? was. Is the camshaft for an all fuel engine the same as a gas engine. I verified the timing marks to crankshaft several times. Just can't understand why My engine is backfiring through the intake. Is it possible that my intake/exhaust manifold gasket leaks. I'm just dumb founded by what should be an easy solution. The compression is 110 in both cylinders. Governor and mag position have been checked several times. If I switch the plug wires in pops (some)through both exhaust and intake.

 

[Mark-Ia]

B217R to ser# 200999, B2284R ser# 201000 to the end of production. The manifolds are known to rust out internally.

 

[buickanddeere]

If you do eventually go into the cam. Instead of another worn out cam , have the existing came and followers re-ground to modern specs. I agree that leaking manifolds are a strong possibility. Sticking valves and weak valve springs do occur on occasion. Has somebody else taken this tractor apart and botched the timing upon assembly .

 

[nutsoverJD]

B217R to ser# 200999, B2284R ser# 201000 to the end of production. The manifolds are known to rust out internally.

So I need to verify that I have the correct cam for this 201000 and up model. Do you know how to identify the differance?

 

[nutsoverJD]

If you do eventually go into the cam. Instead of another worn out cam , have the existing came and followers re-ground to modern specs. I agree that leaking manifolds are a strong possibility. Sticking valves and weak valve springs do occur on occasion. Has somebody else taken this tractor apart and botched the timing upon assembly .

I bought this B non running and definitely someone has messed with it. I have checked the timing on the crank and cam, it is correct. I will look into the manifold to see if that is my problem.

 

[Fixingfarmer]

All fuel and gas should be the same cam the manifold however is different it gets hotter and both can crack a lot of people replace an all fuel manifold with a gas since not a whole lot of kerosene is used any more. Or even build their own. New manifolds of both types are sold I’ve seen a lot of those ears broken off that hold them on. My A was one had a bunch of soft bolts in it too instead of studs you could see the problem in that case

I 3rd the Manifold suggestion they can crack internally as well and cause a lean condition or even carb problem are significantly more likely than a cam issue

The other thing to check is any air leaking in between carb and manifold at that gasket

If you have the correct valve opening at the mark on the flywheel, and spark at the other correct mark, and they both the push rods move the same amount, and you have compression, AND you have the correct valve lash everything should be good down there time to move up.

 

[used red MN]

Has this tractor never ran while in your possession? If you go that far as to pull the manifold there should be a way to fill it with water on the intake side to see if it passes into the exhaust side.

Edit: I see you said bought as a non-runner in reply 5.

 

[nutsoverJD]

All fuel and gas should be the same cam the manifold however is different it gets hotter and both can crack a lot of people replace an all fuel manifold with a gas since not a whole lot of kerosene is used any more. Or even build their own. New manifolds of both types are sold I’ve seen a lot of those ears broken off that hold them on. My A was one had a bunch of soft bolts in it too instead of studs you could see the problem in that case

I 3rd the Manifold suggestion they can crack internally as well and cause a lean condition or even carb problem are significantly more likely than a cam issue

The other thing to check is any air leaking in between carb and manifold at that gasket

If you have the correct valve opening at the mark on the flywheel, and spark at the other correct mark, and they both the push rods move the same amount, and you have compression, AND you have the correct valve lash everything should be good down there time to move up.

I still need to check the manifold. I'm sure my carb gasket is good. These pics are from my manual. I know my exhaust valve is off accordingly to my LHEO mark. Read pic one first

 

[Fixingfarmer]

I believe it was already asked if the v marks inside the tractor on the crank, cam idler and cam gear all are timed correctly by opening the top cover and looking down inside? Should be some internal v marks

the v mark on the outside will just tell position of crank if someone moved something that won’t tell you much I had someone attempting to replace a crankshaft got it miss timed and I ended up lifting governor housing up a hair to line everything crank, idler and cam back up

 

[used red MN]

I believe it was already asked if the v marks inside the tractor on the crank, cam idler and cam gear all are timed correctly by opening the top cover and looking down inside? Should be some internal v marks

the v mark on the outside will just tell position of crank if someone moved something that won’t tell you much I had someone attempting to replace a crankshaft got it miss timed and I ended up lifting governor housing up a hair to line everything crank, idler and cam back up

In one of his other threads he said he has done this.

 

[Fixingfarmer]

If that’s checked spark at the impulse mark would be the last thing to check and then move on to air and fuel issues

They can backfire with a lean condition
(Struggle struggle smoke a bit POP!)

Trying a bit of ether does it do the same backfire or does it pickup for a second and try to go.

 

[used red MN]

If that’s checked spark at the impulse mark would be the last thing to check and then move on to air and fuel issues

They can backfire with a lean condition
(Struggle struggle smoke a bit POP!)

Trying a bit of ether does it do the same backfire or does it pickup for a second and try to go.

I am not sure how close you follow these types of threads, this one seems to be a stumper. He has 3 or 4 other threads on this, his first in late February in the Restoration Processes form which you replied to. Another under the same title “no start JD B” here on the JD forum.
Not sure if you know this but you can easily see a member’s past posts by hovering over his username by his post, then you will see “Messages” at the lower left with a number below it. Clicking that number brings up his posts. Just incase you use a phone they require you to click the username to open it.

 

[nutsoverJD]

If that’s checked spark at the impulse mark would be the last thing to check and then move on to air and fuel issues

They can backfire with a lean condition
(Struggle struggle smoke a bit POP!)

Trying a bit of ether does it do the same backfire or does it pickup for a second and try to go.

This is a 1950ish machine with electric start. My fly wheel is faintly marked with no impuls markings. I had to verify TDC and go from there. It has some TDC timing degree marks and LHEO but not even in the ball park of either position. I have verified the weight position on both the flywheel and clutch they are correct. The valves are out of time to the Manual specs of opening and closing position slightly. It seem that the cam is from a pre 2001000 motor. The intake should still be close at TDC but it seems to be slightly open on both spark/waste spark of the mag.

 

[Mike(NEOhio)]

Your posts are a bit confusing to me. You say you have "checked" all the timing. Are your rocker arm clearances correct? That can affect the valve opening. Missing marks on the flywheel? Post some pictures of the flywheel, in detail, of all markings you can find on it and the crankshaft end. Are you sure it has the correct flywheel. You should find a cast-in part number, may be on the inner side. Not trying to be critical here but you're new to these things and we all have to go through a learning curve. So I have to question your checking. Do you have any sort of manual? I get by fine with the I&T. I think it's unlikely the camshaft has been changed but it would have a part number on it. Trouble is you can't see it. Please don't take offense at my comments, I'm trying to help.

 

[Fixingfarmer]

I have hopefully attached the 2 marks to use to adjust the valves this morning as I had to get the mower setup for spring on the A but the setup is the same

The cover picture you show in the previous picture should work for l.h. Impulse

If you would rather use the side of the transmission cover it is 120 degrees counterclockwise from the LHEO that you should have to the lh impulse mark (or 2 flats of the crankshaft nut make your own mark by putting crank in that position and silver sharpie it and the side of trans mark so you could use a timing light)

 

[Fixingfarmer]

I suppose measuring push rod length might be something else good to check you are right SM 2004 spends a lot of time on the earlier styled tractors I’ve always been told on my 52 A that a 60 manual would be better in your case maybe a 50.

 

[buickanddeere]

I have hopefully attached the 2 marks to use to adjust the valves this morning as I had to get the mower setup for spring on the A but the setup is the same

The cover picture you show in the previous picture should work for l.h. Impulse

If you would rather use the side of the transmission cover it is 120 degrees from the LHEO that you should have to the lh impulse mark (or 2 flats of the crankshaft nut make your own mark by putting crank in that position and silver sharpie it and the side of trans mark so you could use a timing light)

Is the flywheel mark lined up with the flywheel mark ?

 

[buickanddeere]

Stick a dowel into the spark plug hole . Rock the flywheel back and forth . Mark rack limit then measure to the half way point . To find true TDC .

 

[Mike(NEOhio)]

Stick a dowel into the spark plug hole . Rock the flywheel back and forth . Mark rack limit then measure to the half way point . To find true TDC .

That won't work on a 2-cyl. Plugs are in the cylinder wall and pistons don't come up that far.

 

[nutsoverJD]

I suppose measuring push rod length might be something else good to check you are right SM 2004 spends a lot of time on the earlier styled tractors I’ve always been told on my 52 A that a 60 manual would be better in your case maybe a 50.

I do have a copy of the factory manual for the B