77' JD 300 Rough 2nd Start

Technical topics related to machines powered by Kioritz/CCW & Kohler motors.
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no1deerepower

77' JD 300 Rough 2nd Start

Post by no1deerepower »

I recently was riding my 77 John Deere 300 a couple miles out in our bean fields. While it was running it ran excellent and had power throughout the power band. I stopped to take a break and I could not get it restarted again. Turning it over it sounded different than normal; sort of a weird "muffle". The spark was excellent and gas was getting to the engine. What could be the problem?
I have had this happen before and when I let it cool down completely, It runs just fine.

Thank You
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400brian
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77' JD 300 Rough 2nd Start

Post by 400brian »

Has anything been done to the engine? Re-build, re-seal ?

'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
no1deerepower

77' JD 300 Rough 2nd Start

Post by no1deerepower »

I recently completely rebuilt the engine. I put new seals and gaskets in. Could I have put it back together incorrectly?
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400brian
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77' JD 300 Rough 2nd Start

Post by 400brian »

From your description of the problem, it's really hard to say.

Might you be getting a vapor lock issue? Were the plugs wet?

'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
ICCSF 108
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77' JD 300 Rough 2nd Start

Post by ICCSF 108 »

Brian, what if after running a while & getting hot, a old rusted muffler fell apart & the debris is blocking the outlet??

Kenny
AKA: Kenny, Grumpy, Mr. Richard Head
"I Hunt For it, Purchase it, Haul it, Sometimes Repair it, Sometimes Break it, Then Fix it Again, Label it, Warehouse it, Talk About it, So NOW, HOW Can I Take Any Less $$ For It?"
"God I love the smell of KLOTZ in the morning, That smell, you know that Gasoline/Oil Smell, MAKES the whole place SMELL like.. LIKE VICTORY. You know someday the 2 strokers are gonna end..."
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JDT
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77' JD 300 Rough 2nd Start

Post by JDT »

I like that idea Kenny.

Pull the exhaust off and try and start it. Of course you wont want to drive it that way.
Todd Schrupp

Milbank SD
no1deerepower

77' JD 300 Rough 2nd Start

Post by no1deerepower »

I will try looking at the exhaust this afternoon.

What should I do if it is a vapor lock problem? I don't quite understand what a vapor lock entails also.

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400brian
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77' JD 300 Rough 2nd Start

Post by 400brian »

What should I do if it is a vapor lock problem? I don't quite understand what a vapor lock entails also.
Take a look at the routing of your fuel lines, keeping them away from heat sources like the exhaust.
Originally, the '73s on up had insulation on the aluminum firewall. On all my sleds, this material is all gone. I appear to be having some issues on my '74 X8 ( re-starting after warmed up ) so I'm thinking of replacing that insulation to see if that helps.

If the fuel becomes warm enough to vaporize in the lines or carb, the fuel pump won't pull fuel, as the vapor can be compressed, and the Walbro carb won't function properly because it is designed to meter liquid.

We had a situation on Troy Miley's 400 last Feb at the HOF, where it died while idling, and refused to re-start. Troy had a squeeze bulb in the supply line, so we could pump fuel around the system, but it still refused to start, and the plugs remained bone dry.
I remain mystified by that one. It started right up when he got home.

'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
ICCSF 108
Posts: 4369
Joined: Sun Jul 17, 2005 12:00 am
Real Name: Kenny Heins, AKA Grumpy
Location: Blue Springs Mo.
Contact:

77' JD 300 Rough 2nd Start

Post by ICCSF 108 »

When I worked at the University as the Transportation Supervisor the Dodge squad cars always vapor locked in the hot summer days, what we found with them was the fuel tanks weren't vented or the venting got clogged somewhere so all we did is drilled a small hole in the gas caps to vent the tank, so from then on we had summer fuel caps & didn't completely fill the tanks, & winter fuel caps where we could fill the tanks up..
I wouldn't drill the cap on a snowmobile & I'm not sure if your sled has a OEM vented cap?? but what I would do next time you warm the sled up good & the stop it & if it won't start again then I would loosen the cap & then try starting it, if it starts then it definitely is a vapor lock problem where it's not drawing fuel from the tank..


Kenny
AKA: Kenny, Grumpy, Mr. Richard Head
"I Hunt For it, Purchase it, Haul it, Sometimes Repair it, Sometimes Break it, Then Fix it Again, Label it, Warehouse it, Talk About it, So NOW, HOW Can I Take Any Less $$ For It?"
"God I love the smell of KLOTZ in the morning, That smell, you know that Gasoline/Oil Smell, MAKES the whole place SMELL like.. LIKE VICTORY. You know someday the 2 strokers are gonna end..."
Do Anti-War Protesters have reunions? If so what do they TALK about?
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