B7100 hard to start

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Sandpoint, ID
i understand what you are saying, my current head gasket is 1.6mm… once I remove it and install the factory head gasket I was unsure if I would have the proper clearance 0.6mm or if I would need a shim to get enough clearance. Because both the cylinder head and block surface were machined.
per the book factory gasket is 1.05-1.15 after torqued.
Your not understanding what I'm saying.
QUIT GUESSING... Pull the head and measure it to get an exact answer.
The distance from the top of the piston to the top of the block will give you an exact answer.

And if the machinist took material off the top of the block without taking off any material where the Injection pump is (which will be the first time I've ever heard of any one doing this), then you will see a step and know how much he took off, and if that amount is .20' then bob's your uncle get the shim.
 

Brandonallen

Member

Equipment
1991 B7100 hst 4x4
Dec 4, 2021
39
3
8
Ohio
Your not understanding what I'm saying.
QUIT GUESSING... Pull the head and measure it to get an exact answer.
The distance from the top of the piston to the top of the block will give you an exact answer.

And if the machinist took material off the top of the block without taking off any material where the Injection pump is (which will be the first time I've ever heard of any one doing this), then you will see a step and know how much he took off, and if that amount is .20' then bob's your uncle get the shim.
I know he did not machine where the injection pump mounts because it was not shiny and clean. The deck surface was clean but possibly he cleaned another way without taking off material. I know he said he didn’t take any off the pump surface. I am just the middle man as it is a family members tractor I am volunteering my time and labor to fix for them. I did not see a lip between the ip mounting surface and head surface.
I will be taking head off to measure piston to deck clearance
 

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
31,421
7,244
113
Sandpoint, ID
I know he did not machine where the injection pump mounts because it was not shiny and clean. The deck surface was clean but possibly he cleaned another way without taking off material. I know he said he didn’t take any off the pump surface. I am just the middle man as it is a family members tractor I am volunteering my time and labor to fix for them. I did not see a lip between the ip mounting surface and head surface.
I will be taking head off to measure piston to deck clearance
If there is no visible step, he took off so little it won't matter, then you can safely just put a OEM gasket on it and it will be right.
NO SEALER on the head gasket or injection pump shims as that too will change it.
And do not oil the head bolts as that will change the squash too.

But a measurement or two will make everyone breath easier.
One other advantage of doing a good measure you can confirm the pistons are right and the rods are not bent.
 
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Brandonallen

Member

Equipment
1991 B7100 hst 4x4
Dec 4, 2021
39
3
8
Ohio
If there is no visible step, he took off so little it won't matter, then you can safely just put a OEM gasket on it and it will be right.
NO SEALER on the head gasket or injection pump shims as that too will change it.
And do not oil the head bolts as that will change the squash too.

But a measurement or two will make everyone breath easier.
One other advantage of doing a good measure you can confirm the pistons are right and the rods are not bent.
New oem head gasket is on, all the measurements checked out. Compression is now 350 while cranking. Starts and runs great. But now have a pinging/knock sound right beside the injection pump. The injectors are also brand new from Oregon. No noticeable smoke from the exhaust and runs very smooth. Oil pressure is good. It never had any noises before, does not sound like bottom end, I even double checked the valve lash. Any ideas what could cause a noise over there?
 
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North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
31,421
7,244
113
Sandpoint, ID
New oem head gasket is on, all the measurements checked out. Compression is now 350 while cranking. Starts and runs great. But now have a pinging/knock sound right beside the injection pump. The injectors are also brand new from Oregon. No noticeable smoke from the exhaust and runs very smooth. Oil pressure is good. Any ideas what could cause a noise over there?
Lift pump, Injection pump, or Hydraulic pump.

Noises are really hard to hear in a text. 🤫

Make a video of it and post it on youtube and give us a link to See / Hear it.
 

Brandonallen

Member

Equipment
1991 B7100 hst 4x4
Dec 4, 2021
39
3
8
Ohio
Got back out there tonight. Finished bolting up the radiator, replaced the stripped clamps at the hydraulic cooler, reverified oil pressure 45 psi while cranking cold, also added some anti gel for good measure. So then I rebled the fuel line at the injection pump, and bled each injector individually again while cranking.
Started it up and the hammering noise was there, revved it up and it cleared up. Let it run for a few minutes and then returned to idle and the noise was gone. It ran for probably 15 minutes, no smoke out of exhaust, no blow by, very smooth. Once again brought back to idle and the hammering noise was still gone.
I am unsure if it was the hydraulic pump sucking in air at those stripped clamps, possibly air In the injection pump or injectors, or possibly partially gelled fuel(doubtful). I will follow up in a day or so with the owner when they start it again to make sure the noise is still gone. It’s been single digits here so probably won’t be using it much for a while. I appreciate all of the advice and information. Would be up a creek without a paddle without you all
 

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
31,421
7,244
113
Sandpoint, ID
Got back out there tonight. Finished bolting up the radiator, replaced the stripped clamps at the hydraulic cooler, reverified oil pressure 45 psi while cranking cold, also added some anti gel for good measure. So then I rebled the fuel line at the injection pump, and bled each injector individually again while cranking.
Started it up and the hammering noise was there, revved it up and it cleared up. Let it run for a few minutes and then returned to idle and the noise was gone. It ran for probably 15 minutes, no smoke out of exhaust, no blow by, very smooth. Once again brought back to idle and the hammering noise was still gone.
I am unsure if it was the hydraulic pump sucking in air at those stripped clamps, possibly air In the injection pump or injectors, or possibly partially gelled fuel(doubtful). I will follow up in a day or so with the owner when they start it again to make sure the noise is still gone. It’s been single digits here so probably won’t be using it much for a while. I appreciate all of the advice and information. Would be up a creek without a paddle without you all
Bet it was air in the hydraulic pump.
Glad to here you got it going.
 
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