1970 mercury thunderbolt 650

[Lennyb5641]

How can I tell if my reeds are bad without breaking down the motor? The motor is a 1970 mercury thunderbolt 650, 4 cylinder, 65 hp

 

[Faztbullet]

Re: 1970 mercury thunderbolt 650

Reeds rarely go bad but when they do they cause a spit back or pffting noise thru carb. Whats you engine doing?

 

[Lennyb5641]

Re: 1970 mercury thunderbolt 650

It's making the sound you described through the exhaust not the carb and it won't start, the guy at the marina said he thinks it might be the reeds. I don't have a gauge to check compression but it has really good spark and is getting fuel.

 

[mr 88]

Re: 1970 mercury thunderbolt 650

Was the motor running OK ? Did you buy it like this ? Did you do carb rebuild and this is the end result ? Have you done a link n sync ? Coming out the exhaust leads me more to your timing. As noted reeds rarely go so I would be looking else where. Need more history on when the issue started and what lead up to it.

 

[Lennyb5641]

Re: 1970 mercury thunderbolt 650

The motor was running really good, then a couple days later we were going out and it wouldn't start, the only thing I have done to this motor was change the plugs and I was very careful not to cross the wires, I did just change the diaphragms in the two fuel pumps thinking that was the problem. Other people told me it sounds like its out of time but I haven't messed with any of that. I have had this motor for about two months

 

[Faztbullet]

Re: 1970 mercury thunderbolt 650

Check the carbon tip in distributor cap as if worn out the carbon debris will make it pop out of time..like a wet cap on a auto.

 

[Lennyb5641]

Re: 1970 mercury thunderbolt 650

If that's not the problem then what's another cause?