thunderbolt 500

[fuzzyzuk]

ive recently picked up a 14 ft fiberform and it has a merc thunderbolt 500 on the back not sure of year has red decals?
anyways im wondering if anybody knows the order in which the spark pllug wire should be on the distributor, i replaced the number 4 plug with the number 3 and can now get her to run a bit when there in the right order nothing but a backfire every now and then
i also belive the fuel pump is shot I undid the line and cranked the motor nothing pumped am i on the right track? thanks guys!

 

[fuzzyzuk]

Re: thunderbolt 500

ive recently picked up a 14 ft fiberform and it has a merc thunderbolt 500 on the back not sure of year has red decals?
anyways im wondering if anybody knows the order in which the spark pllug wire should be on the distributor, i replaced the number 4 plug with the number 3 and can now get her to run a bit when there in the right order nothing but a backfire every now and then
i also belive the fuel pump is shot I undid the line and cranked the motor nothing pumped am i on the right track? thanks guys!

also forgot to mention i did a compression check
cyl#1 130
cyl#2 132
cyl#3 130
cyl#4 136

 

[fuzzyzuk]

Re: thunderbolt 500

Bump anyone?

 

[Chris1956]

Re: thunderbolt 500

A lot of the distributor caps had cast in numbers. The firing order is not 1-2-3-4, so that really cuts down on the possibilities. Why not use a screwdriver thru the plug holes to figure it out. 1-3-4-2 is likely

 

[fuzzyzuk]

Re: thunderbolt 500

I'll give that a try, but I still won't know which order the plug wires go on the distributor

 

[spamn]

Re: thunderbolt 500

Pleas provide a serial number so that I can verify the year. I have a Merc 500 and my Seloc manual says 1-3-2-4 order for almost all 500s. Again, I can confirm this with a serial number.

 

[Chris1956]

Re: thunderbolt 500

Hey Fuzzy, Once you figure out which way the distributor rotates, you know the order the wires need to be installed. With the top cylinder at top dead center, you know which wire is for the top cylinder.

 

[Maxz695]

Re: thunderbolt 500

#1 on the distributor will be where the rotor is pointing at top dead center of the cylinder on the power stroke when you find that then put the 3 2 4 in the rotation of the rotor

 

[Gomer50]

Re: thunderbolt 500

On the distributor cap there are numbers stamped on it 1,2,3,4. Top cylinder is 1 next one down is 2 and 3 and 4. Cant go wrong.Distributor Cap goes on only one way.

 

[fuzzyzuk]

Re: thunderbolt 500

Thanks guys good info I will grab the serial number in about an hour

 

[Moxie]

Re: thunderbolt 500

I have a 1968 500 I have the wires labeled. Not sure if it's the same year or not, but let me know if you want a photo.

 

[Moxie]

Re: thunderbolt 500

Here is the order from my 1968 500 (See photo).
Side:

Rear:

 

[fuzzyzuk]

Re: thunderbolt 500

My sn is 2630467 if that helps also what year is my motor

 

[spamn]

Re: thunderbolt 500

My sn is 2630467 if that helps also what year is my motor

Appears to be a 1969. Someone please correct me if I'm wrong.

For 1969 the firing order is still 1-3-2-4 on the Merc 500

 

[fuzzyzuk]

Re: thunderbolt 500

Does anybody know if the spark plug wire order is the same as the 68? Pictured above,on the distributor

 

[fuzzyzuk]

Re: thunderbolt 500

doesnt seem to be the same wont run that way

 

[Chris1956]

Re: thunderbolt 500

OK, Check the pistons with a screwdriver thru the plug holes. Start with #1 and turn the flywheel 1/4 turn and see which piston is highest. That is next to fire. Turn another 1/4 turn and see which one is highest and therefore next to fire. etc....

 

[fuzzyzuk]

Re: thunderbolt 500

OK, Check the pistons with a screwdriver thru the plug holes. Start with #1 and turn the flywheel 1/4 turn and see which piston is highest. That is next to fire. Turn another 1/4 turn and see which one is highest and therefore next to fire. etc....

i think i figured it out im pretty sure my timing belt has skipped
does anybody know the procedure to replace the timing belt! thanks