Over heat/distributor cap melting?

[ancomcabs]

Running the 630 today, not too long probably half an hour or so and I noticed it seemed to start running pretty rough, stopped working and lowered throttle to take a look, the distributor cap started melting, one wire was melted off completely and the others were getting soft. The inside of the distributor seems ok. Please take a look at the pictures, can the exhaust manifold get hot enough to do this during normal operation? What would cause the engine to get so hot that this happens? Engine light never came on so I'm not sure if it was close to overheating or not? Any ideas? Pictures: http://screencast.com/t/cHCkiOd0 http://screencast.com/t/eIWJMdTudY

 

[OldMachinist]

If the fuel mixture is too lean the exhaust manifold might get red hot and radiate enough heat to do that. I'd also clean out the cooling fins on the heads and cylinders. With a air cooled engine I think the only idiot light is low engine oil pressure.

 

[ancomcabs]

If the fuel mixture is too lean the exhaust manifold might get red hot and radiate enough heat to do that. I'd also clean out the cooling fins on the heads and cylinders. With a air cooled engine I think the only idiot light is low engine oil pressure.

It was warm back there but certainly not red hot. I can take the covers off the heads and check the cooling fins tomorrow. The engine seems to run smooth both at idle and under load so I'm not sure how to tell if it is too lean or not, any suggestions?

 

[OldMachinist]

It was warm back there but certainly not red hot. I can take the covers off the heads and check the cooling fins tomorrow. The engine seems to run smooth both at idle and under load so I'm not sure how to tell if it is too lean or not, any suggestions?

If I remember correctly there's no high speed adjustment needle on the Wisconsin carbs. So for it to be lean the main jet would have some crud in it. The ignition timing can also affect the running temp. You may want verify it.Timing has to be set with the engine running at 1800 rpms.

 

[ancomcabs]

If I remember correctly there's no high speed adjustment needle on the Wisconsin carbs. So for it to be lean the main jet would have some crud in it. The ignition timing can also affect the running temp. You may want verify it.Timing has to be set with the engine running at 1800 rpms.

So Checked the cooling fins, some crud but not too bad, checked timing it was OK, old plugs were kind of black so it's probably running too rich rather than lean, new plugs, distributor cap and wires, pretty much starts right up but a little louder than I remember check the muffler and there is about a 1 inch hole rusted thru right above the distributor-blowing hot air out like a furnace! Patched the hole temporarily with sheet metal and wire and ran it for a while, no problems. Moral of the story for me Check the obvious first! Now on to the next thread, where can I find a muffler for the VH4D/Bobcat 630? Any after market source? Thanks

 

[Tazza]

So Checked the cooling fins, some crud but not too bad, checked timing it was OK, old plugs were kind of black so it's probably running too rich rather than lean, new plugs, distributor cap and wires, pretty much starts right up but a little louder than I remember check the muffler and there is about a 1 inch hole rusted thru right above the distributor-blowing hot air out like a furnace! Patched the hole temporarily with sheet metal and wire and ran it for a while, no problems. Moral of the story for me Check the obvious first! Now on to the next thread, where can I find a muffler for the VH4D/Bobcat 630? Any after market source? Thanks

That would do it. Glad it was so simple.

 

[ancomcabs]

That would do it. Glad it was so simple.

Yeah that part is simple, finding a muffler for reasonable cost probably won't be so easy!

 

[Tigerhaze]

Yeah that part is simple, finding a muffler for reasonable cost probably won't be so easy!

I had a similar heating issue on my 630 due to a rusted muffler- melted the air filter indicator.
I am in the same boat as you on the muffler- dealer wants $380 before tax. I am probably going to see if a local muffler shop can custom make one.

 

[ancomcabs]

I had a similar heating issue on my 630 due to a rusted muffler- melted the air filter indicator.
I am in the same boat as you on the muffler- dealer wants $380 before tax. I am probably going to see if a local muffler shop can custom make one.

I'm going to give the Napa one a try, especially since the spark arrestor feature is not important to me. I did get a price from my local dealer at 242.97. Can't imagine why one would be so much higher (380) The part number they gave me was: 6560339

 

[Tigerhaze]

I'm going to give the Napa one a try, especially since the spark arrestor feature is not important to me. I did get a price from my local dealer at 242.97. Can't imagine why one would be so much higher (380) The part number they gave me was: 6560339

The part number I have for the muffler is 6560582- that number came from the parts manual for a later S/N (there is a serial number break). I'll have to look at home to see if your part number corresponds to the early S/N or something else.