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Craftman 5000 Watt Generator hard Starting when Hot

#1

J

jono252525

Craftsman 5000 Watt Generator, hard Starting when Hot. Engine Tecumseh model HM100
Start in 2 pull when cold and Run Perfect even at 6500 watt ( Peak time) ,but if you stop it to refuel , it take about 10 pull before it start.
The Carburator is all clean and adjusted (ultrasonic) , the valve are good .008 intake .012 ex , new head gasket, Governor
adjusted, air filter clean, the spark plug look like new J17 LM.
I need your help.


#2

F

Forest#2

Does it have the electric starter also??
Them 10 HP Tecumsehs are not user friendly to rope crank is why I ask.


#3

J

jono252525

Forest#2 said:
Does it have the electric starter also??
Them 10 HP Tecumsehs are not user friendly to rope crank is why I ask.
Click to expand...
No


#4

A

Auto Doc's

If it has a low oil switch at the bottom, on the side of the block, unplug it and see if it will start when hot. These switches were problematic on many engines.


#5

F

Forest#2

Also replace the spark plug and gap it per specs. (and fresh fuel)

You can download a free Tecumseh L-head manual on-line also.

I've purposely converted those HH100 Tecumsehs to electric start due to hard cranking/starting with the pull rope after killing the engine in cold weather when they are really needed. I found the used parts for such at a reasonable price on flea bay. Most of those HH100's have the starter holes already drilled and tapped on the block.
I just used a 2 amp 120v battery charger that kept the battery charged when the generator was running and I did not have to add a charging system to the engine.


#6

J

jono252525

Auto Doc's said:
If it has a low oil switch at the bottom, on the side of the block, unplug it and see if it will start when hot. These switches were problematic on many engines.
Click to expand...
I did that but no difference


#7

J

jono252525

Forest#2 said:
Also replace the spark plug and gap it per specs. (and fresh fuel)

You can download a free Tecumseh L-head manual on-line also.

I've purposely converted those HH100 Tecumsehs to electric start due to hard cranking/starting with the pull rope after killing the engine in cold weather when they are really needed. I found the used parts for such at a reasonable price on flea bay. Most of those HH100's have the starter holes already drilled and tapped on the block.
I just used a 2 amp 120v battery charger that kept the battery charged when the generator was running and I did not have to add a charging system to the engine.
Click to expand...
The fly weel dont have the gear


#8

J

jono252525

Forest#2 said:
Also replace the spark plug and gap it per specs. (and fresh fuel)

You can download a free Tecumseh L-head manual on-line also.

I've purposely converted those HH100 Tecumsehs to electric start due to hard cranking/starting with the pull rope after killing the engine in cold weather when they are really needed. I found the used parts for such at a reasonable price on flea bay. Most of those HH100's have the starter holes already drilled and tapped on the block.
I just used a 2 amp 120v battery charger that kept the battery charged when the generator was running and I did not have to add a charging system to the engine.
Click to expand...
I have the manual but no answer for the problem I have and the Spark plug is new and at .030 gap but I wil try a other one.
By the way The part list is not showing a gasket for the muffler so I did not put one, could that help to add one?


#9

A

Auto Doc's

jono252525 said:
Craftsman 5000 Watt Generator, hard Starting when Hot. Engine Tecumseh model HM100
Start in 2 pull when cold and Run Perfect even at 6500 watt ( Peak time) ,but if you stop it to refuel , it take about 10 pull before it start.
The Carburator is all clean and adjusted (ultrasonic) , the valve are good .008 intake .012 ex , new head gasket, Governor
adjusted, air filter clean, the spark plug look like new J17 LM.
I need your help.
Click to expand...
I suspect the rings are worn or the oil is too light. Most of these early engines uses straight SAE30 engine oil.

Are you also trying to use the choke when starting hot. Some engines with a lot of wear need the choke even when hot.


#10

J

jono252525

Auto Doc's said:
I suspect the rings are worn or the oil is too light. Most of these early engines uses straight SAE30 engine oil.

Are you also trying to use the choke when starting hot. Some engines with a lot of wear need the choke even when hot.
Click to expand...
I try with and with out the choke. and The compression is good 70 psi because of decompression system and no smoke.
I will try new oil 10W30 I like Castrol brand. Ho, the Coil module is new also.


#11

A

Auto Doc's

70 PSI is barely enough to support combustion, but it has a compression relief so that should really not be an issue.

New coil? As in Amazon? I avoid Amazon due to the many problems I've had over the years.


#12

A

Auto Doc's

One thing that comes to mind is fuel percolation in the fuel bowl after shutdown. All that post-shutdown engine heat directly effects the carburetor.

Years ago, we had to look around at similar models to find an insulator/ heat shield that mounted with the muffler, but extended down to protect the carburetor from heat absorption,

This heat shield greatly reduced the percolation problems and improved the hard start when hot problems.

I looked on Ebay and they show a couple of different used ones for the Tecumseh HM100. Maybe one will be a good fit for your engine.

Hope this info helps you,


#13

J

jono252525

Auto Doc's said:
One thing that comes to mind is fuel percolation in the fuel bowl after shutdown. All that post-shutdown engine heat directly effects the carburetor.

Years ago, we had to look around at similar models to find an insulator/ heat shield that mounted with the muffler, but extended down to protect the carburetor from heat absorption,

This heat shield greatly reduced the percolation problems and improved the hard start when hot problems.

I looked on Ebay and they show a couple of different used ones for the Tecumseh HM100. Maybe one will be a good fit for your engine.

Hope this info helps you,
Click to expand...
I will check that,
Thank youi


#14

A

Auto Doc's

Here is one example, not sure if it is correct:

www.ebay.com

Genuine Tecumseh 37148 Baffle Shield Heat (#2087) | eBay

Genuine Tecumseh 37148 Baffle Shield Heat (#2086). Condition is used. Shipped with USPS First Class.
www.ebay.com

I guess I should ask if all other tin heat shields are in place because many people often make the mistake of removing them thinking that it improves cooling. It does just the opposite. The heat shield tins are in place to ensure the cooling air from the flywheel fins is forced in the proper directions. That is vital for any air-cooled engine.


#15

J

jono252525

Auto Doc's said:
Here is one example, not sure if it is correct:

www.ebay.com

Genuine Tecumseh 37148 Baffle Shield Heat (#2087) | eBay

Genuine Tecumseh 37148 Baffle Shield Heat (#2086). Condition is used. Shipped with USPS First Class.
www.ebay.com

I guess I should ask if all other tin heat shields are in place because many people often make the mistake of removing them thinking that it improves cooling. It does just the opposite. The heat shield tins are in place to ensure the cooling air from the flywheel fins is forced in the proper directions. That is vital for any air-cooled engine.
Click to expand...
Thank you for the information, The problem for me is the price in CA for me $7.00 US= $10.00 and the shipping is $22.00 CA so, I will use a metal plate and make my self one and I will copy on the add you send me.
Thank you again.


#16

A

Auto Doc's

Sounds like a sensible plan. Hope it works for you.

As a temporary idea to test the theory use a wad of fiberglass house insulation and wrap it in heavy tin foil or tin foil tape, then shoved in between the side of the block and the carburetor, especially at the carb bowl area.


#17

S

slomo

jono252525 said:
I will try new oil 10W30
Click to expand...
10w-30 will shear down awful fast in an air cooled engine. Briggs, Kawisaki, Kohler and so on state multi-grade oils will be consumed more compared to a straight 30W. Meaning you will need to check it at every use. I do that anyway with all oils.

Use the oil your engine manual says to.


#18

sgkent

sgkent

for giggles. Next time you are in this place, pull the spark plugs, blow compressed air into each cylinder, and blow the plugs off too. Then put them back and see if it starts. If it does then it will prove that the engine is flooded. Another possibility is that the choke system is closing and that makes it too rich. Another issue is spark. Some inferior brands have been reported to cause issues like this - torch or ngk counterfeits. Put in some genuine plugs you got at your local auto parts store and see if it helps. I will say that when I read someone wants to make things themselves instead of spending $20 to solve a problem, I typically run from that person because someone unwilling to buy quality parts ends up with unsolvable problems.


#19

J

jono252525

Auto Doc's said:
Sounds like a sensible plan. Hope it works for you.

As a temporary idea to test the theory use a wad of fiberglass house insulation and wrap it in heavy tin foil or tin foil tape, then shoved in between the side of the block and the carburetor, especially at the carb bowl area.
Click to expand...
OK I will try that ferst.


#20

J

jono252525

sgkent said:
for giggles. Next time you are in this place, pull the spark plugs, blow compressed air into each cylinder, and blow the plugs off too. Then put them back and see if it starts. If it does then it will prove that the engine is flooded. Another possibility is that the choke system is closing and that makes it too rich. Another issue is spark. Some inferior brands have been reported to cause issues like this - torch or ngk counterfeits. Put in some genuine plugs you got at your local auto parts store and see if it helps. I will say that when I read someone wants to make things themselves instead of spending $20 to solve a problem, I typically run from that person because someone unwilling to buy quality parts ends up with unsolvable problems.
Click to expand...
Read me right: not $20. But $32. CA for a peace of metal, COMME ON !
For the rest, I will check the other things you said.


#21

J

jono252525

slomo said:
10w-30 will shear down awful fast in an air cooled engine. Briggs, Kawisaki, Kohler and so on state multi-grade oils will be consumed more compared to a straight 30W. Meaning you will need to check it at every use. I do that anyway with all oils.

Use the oil your engine manual says to.
Click to expand...
Your Right but I check the oil each time I use it.


#22

F

Forest#2

Couple thing you might try.
First remove all loads on the gen when first starting. (and before killing the gen)

Start it up cold and then kill it before it gets warmed up and go for a re-start. Only let it run for 60-90 seconds) You are mainly checking to see if maybe the hard re-start is not all heat/hot related.

On gens engines when they are not running the governor has the throttle held at wide open. Tie the governor/carb at idle and try a re-start)
Also see if the engine idles good. This is to see if the low jet area on the carb is OK. (It's possible that it runs ok at 3600 rpm but won't idle smooth. (low jet carb issue adding to the hard start issue when hot)

You say the compression is 70. That seems low to me is concerning.
I've never checked the compression on a HM100 but I do know that normally they are very hard to pull through using a rope crank and they also want to kick back if they are not brought up on compression slowly and then pull through. I never could sense that they had a compression release.
(and even harder to hand crank in cold weather for a re-start) Hard manual cranking is main reason why I was doing converts to electric start.

Even with electric start I had to use a very good lawn tractor battery rated for around 250CCA due to the compression.


#23

J

jono252525

Forest#2 said:
Couple thing you might try.
First remove all loads on the gen when first starting. (and before killing the gen)

Start it up cold and then kill it before it gets warmed up and go for a re-start. Only let it run for 60-90 seconds) You are mainly checking to see if maybe the hard re-start is not all heat/hot related.

On gens engines when they are not running the governor has the throttle held at wide open. Tie the governor/carb at idle and try a re-start)
Also see if the engine idles good. This is to see if the low jet area on the carb is OK. (It's possible that it runs ok at 3600 rpm but won't idle smooth. (low jet carb issue adding to the hard start issue when hot)

You say the compression is 70. That seems low to me is concerning.
I've never checked the compression on a HM100 but I do know that normally they are very hard to pull through using a rope crank and they also want to kick back if they are not brought up on compression slowly and then pull through. I never could sense that they had a compression release.
(and even harder to hand crank in cold weather for a re-start) Hard manual cranking is main reason why I was doing converts to electric start.

Even with electric start I had to use a very good lawn tractor battery rated for around 250CCA due to the compression.
Click to expand...
I look at the Cam and on mine there is a release system.
Also
I did like you said adjust the pilot at ideal and the main on I speed.
The engine restart good with no choke if it is not to warm.


#24

Ozcub

Ozcub

Heat sink into carburettor place a heat resistant barrier to shield carb from heat


#25

J

jono252525

I will keep you posted, when I have made the modification.
Thank you.


#26

S

slomo

Do you have a solid flow of fuel AT the carb inlet? Can you drain the fuel tank from/at this same location? Any reductions in flow rate while doing this? Possible tank cap vent?? Trash in the tank and lines. Fuel lines internally deteriorating, clogged filter????

I've never seen a mower engine percolate. They don't run as hot externally as say old GM land cruisers under the hood. Fuel tanks are in free air. Simple rubber hose to the carb.


#27

F

Forest#2

You say it has electronic ign and you replaced the module with a generic???

If so what specs did you set the air gap?

Are you sending fresh fuel to the carb or old fuel with additives?


#28

J

jono252525

slomo said:
Do you have a solid flow of fuel AT the carb inlet? Can you drain the fuel tank from/at this same location? Any reductions in flow rate while doing this? Possible tank cap vent?? Trash in the tank and lines. Fuel lines internally deteriorating, clogged filter????

I've never seen a mower engine percolate. They don't run as hot externally as say old GM land cruisers under the hood. Fuel tanks are in free air. Simple rubber hose to the carb.
Click to expand...
I use an external tank right now


#29

J

jono252525

Forest#2 said:
You say it has electronic ign and you replaced the module with a generic???

If so what specs did you set the air gap?

Are you sending fresh fuel to the carb or old fuel with additives?
Click to expand...
New fuel and .010 inches gap


#30

J

jono252525

I found the problem, the engine front cover on that unit as a big square old at the bottom and the
engine is suppose to have a shield that attache to the 2 engine supports and close the hole when the cover is in place. In my case the shield was missing and the cooling system was loosing all the air under the engine.

Attachments





#31

A

Auto Doc's

That will cause problems for sure. Someone left it off not thinking it was important probably.


#32

G

gregjo1948

jono252525 said:
I try with and with out the choke. and The compression is good 70 psi because of decompression system and no smoke.
I will try new oil 10W30 I like Castrol brand. Ho, the Coil module is new also.
Click to expand...
Get rid of the "decompression system". The oil viscosity has nothing to do with your problem.


#33

F

Forest#2

So the engine was overheating?
Not a good thing.
Good find.
Would be interesting to check the difference in temperature with and without the shield with a IR theromometer.
I use one quite often on equipment, chainsaws, comparing exhaust cylinder temps, detecting dead cylinders when the engine is running.

I see guys quite often operate a engine too long with air cowlings removed when working on a engine allowing the heads to overheat causing more problems.


#34

R

RevB

Auto Doc's said:
70 PSI is barely enough to support combustion, but it has a compression relief so that should really not be an issue.

New coil? As in Amazon? I avoid Amazon due to the many problems I've had over the years.
Click to expand...
Well, that's crap....Continental aircraft engines minimum equates to 40 psi by differential test. 70 is fine for a decompression released engine.


#35

R

RevB

Auto Doc's said:
One thing that comes to mind is fuel percolation in the fuel bowl after shutdown. All that post-shutdown engine heat directly effects the carburetor.

Years ago, we had to look around at similar models to find an insulator/ heat shield that mounted with the muffler, but extended down to protect the carburetor from heat absorption,

This heat shield greatly reduced the percolation problems and improved the hard start when hot problems.

I looked on Ebay and they show a couple of different used ones for the Tecumseh HM100. Maybe one will be a good fit for your engine.

Hope this info helps you,
Click to expand...
Vapor lock....


#36

R

RevB

jono252525 said:
I try with and with out the choke. and The compression is good 70 psi because of decompression system and no smoke.
I will try new oil 10W30 I like Castrol brand. Ho, the Coil module is new also.
Click to expand...
Oil is not the problem....


#37

A

Auto Doc's

RevB said:
Well, that's crap....Continental aircraft engines minimum equates to 40 psi by differential test. 70 is fine for a decompression released engine.
Click to expand...
How can you compare a Continental aircraft engine to this design? They are totally different.


#38

R

RevB

Auto Doc's said:
How can you compare a Continental aircraft engine to this design? They are totally different.
Click to expand...
I can and I did. Multi cylinder vs single is not such a stretch. Both will be down on power and the single more so but it will run at 70. Saying it won't isn't true.


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