Motor transplant in Craftsman lawn tractor 18.5 HP B/S motor to an B/S 20 HP motor.....

[mrbreezeet1]

Will it fit? My buddy can get a good 20 HP B/S motor to replace his 18.5 HP motor, Is the mounting footprint the same?
Sorry don't know the craftsman's lawn tractors model numbers ATM, l can't get ahold of him ATM!

ETA His is a Craftsman model # DLT 3000 he's supposed to let me know what the other Craftsman model is when he gets ahold of the guy selling the motor.

 

[fantastic]

You have to check the motor shaft length and width. It has to match.

 

[ripcord]

Briggs has extensive info online for their motors. Just get the tag numbers and search for them on their site.

 

[mrbreezeet1]

You have to check the motor shaft length and width. It has to match.

He's up in Pittsburgh PA in near Wheeling WV so l can't go right over and help him measure.
If the motor shaft diameter of the new motor is say, larger than his, ls it possible to get a different pulley or bore his out.
I have a metal lathe?

 

[mrbreezeet1]

Briggs has extensive info online for their motors. Just get the tag numbers and search for them on their site.

OK, is that like a tag riveted on to the motors?

 

[Elkins45]

The bolt footprint is the same but you need to make sure that shaft length and diameter match. You also need to make sure the alternator outputs match. Some mowers with electric blade clutches need a higher output in order to function. Older motors for mowers with manual blade engagements have a dual output circuit with DC for charging the battery and AC to run the headlights. It’s possible to swap the stators on many of them, so it might not be a dealbreaker if they don‘t match.

 

[Elkins45]

OK, is that like a tag riveted on to the motors?

On most of the OHV units from the last 20 years it’s stamped into one of the valve covers.

 

[ripcord]

Pretty sure that Craftsman model has a mechanically engaged blade belt.

 

[mrbreezeet1]

The bolt footprint is the same but you need to make sure that shaft length and diameter match. You also need to make sure the alternator outputs match. Some mowers with electric blade clutches need a higher output in order to function. Older motors for mowers with manual blade engagements have a dual output circuit with DC for charging the battery and AC to run the headlights. It’s possible to swap the stators on many of them, so it might not be a dealbreaker if they don‘t match.

I'm pretty sure his is manual blade engagement. He's not "worried" about the headlights, so does it sound like the alternator outputs would still matter?

If the motor shaft diameter of the new motor is say, larger than his, ls it possible to get a different pulley or bore his out.
I have a metal lathe?

Again ^^^^^^^^^^^^^^^^^^^^^^^^^?

 

[mrbreezeet1]

Pretty sure that Craftsman model has a mechanically engaged blade belt.

l think it does too! Yes it does! on phone with him now!

 

[Elkins45]

I'm pretty sure his is manual blade engagement. He's not "worried" about the headlights, so does it sound like the alternator outputs would still matter?

Again ^^^^^^^^^^^^^^^^^^^^^^^^^?

You might have to rewire or replace the electrical connector if they are different. Briggs includes info on how to do this in their manuals. As far as the pulley goes you could probably walk into a good mower shop with the pulley and ask for a similar pulley for a different shaft size and them find one for you. I don’t know if those pulleys have enough extra meat to be bored out.

 

[mrbreezeet1]

He's at the guys house now! He is going to try to get more information regarding Tag numbers and shaft diameter and diameter!

 

[mrbreezeet1]

You might have to rewire or replace the electrical connector if they are different. Briggs includes info on how to do this in their manuals. As far as the pulley goes you could probably walk into a good mower shop with the pulley and ask for a similar pulley for a different shaft size and them find one for you. I don’t know if those pulleys have enough extra meat to be bored out.

OK, I'm sure I can do that!
Sounds Great if we could use a different pulley if needed! He's there now, we will try to get more information.
Thanks guys!

 

[mk378]

In general the shaft is a lot different between electric blade clutch and mechanical.

 

[oldcodger]

The choke\throttle linkage needs to be compatible. That has been the problem area when I have done an engine swap.

 

[mrbreezeet1]

Well he went to look at it, but really couldn't measure the motor shaft, as it was still in the tractor. He is going to take a chance and get it though, and l will update when we {hopefully} get it installed.

 

[mrbreezeet1]

He went and got it, and actually got the motor installed. BUT the only issue he ls having now is the new motor doesn't have a port to on the oil fill tube to hook to his fuel pump that gives the pulse to operate the fuel pump. The guy said his tractor was gravity feed to the carb. ls it possible maybe to switch the oil fill tube from his old motor to the new motor, so he can use his old fuel pump? lt does try to start when he put a little starting fluid in the carb. 0r is there an electric pump on some of these, we could adapt somehow?

 

[Rand]

He went and got it, and actually got the motor installed. BUT the only issue he ls having now is the new motor doesn't have a port to on the oil fill tube to hook to his fuel pump that gives the pulse to operate the fuel pump. The guy said his tractor was gravity feed to the carb. ls it possible maybe to switch the oil fill tube from his old motor to the new motor, so he can use his old fuel pump? lt does try to start when he put a little starting fluid in the carb. 0r is there an electric pump on some of these, we could adapt somehow?

Convert it to electric fuel pump?

although I'm not sure if you would have issues with a gravity fed carb now on an electric.


The converted was onan and we went from the vacuum pulse type to electric.

not gravity fed to electric.

 

[mrbreezeet1]

Convert it to electric fuel pump?

although I'm not sure if you would have issues with a gravity fed carb now on an electric.


The converted was onan and we went from the vacuum pulse type to electric.

not gravity fed to electric.

Well his old motor was the vacuum pulse fuel pump set-up. l hope l made that clear?

 

[Rand]

Well his old motor was the vacuum pulse fuel pump set-up. l hope l made that clear?

To reword what I said:
You arent using the old motor.. or old carb??

if you were you could convert to electric fuel pump no problem.

with the new motor/carb that was setup as gravity fed I am uncertain.
but plenty more people here that know more than I ever will about these types of things..