merc500 1973

[speete1011]

Re: merc500 1973

Alex: Have you removed the idle tube from the carburetor and if so this tube we as a rule never remove unless extremely nessesary. If you have removed it and there is a crack in the brass tube then you should replace it, and saying that it maybe very difficult in getting this part it could very well be NLA and if so may aquired possibly through Tillitson Carburetors in Northern Ireland,GB which is a long way to go to find the part! The Model is stamped on the carburetor if you let me know I may be able to locate the correct part and send it to you, or check with Mercury Marine Ltd. I think they are located on 2395 Meadowpine Blvd. Mississauga, Ontario L5N 7W6 ask for "Leon" in Service/Warranty Department at 1-905-816-4751 this should be his direct line in! You can ask him if the part is still available and if not could you use an alternetive part!<br /><br />Help is here,help me help you!<br /><br />Read & Believe!!<br /><br />Merc!!!

 

[crem1]

Re: merc500 1973

Hi Mercmaster!<br />"I noticed that I have a hairline crack in the IDLE TUBE from bottom to about 3/4 up. Is that tolerable?" <br />The above statement is from my earlier submission on another website. Maybe I did not make myself clear. I solved the problem by getting an IDLE TUBE from a dealer who took it out from an old motor. The other website which I no longer deal with suggested that I take out the IDLE TUBE out of the carburator for proper cleaning. When I took it out I noticed a hairline crack on the tube.<br />The carburators are back in the engine and appear to be functioning OK. <br />Thanks for being patient<br /><br />Alex

 

[timmathis]

Re: merc500 1973

Alex, I guess your next step is set the timing right?

 

[speete1011]

Re: merc500 1973

Alex: Did you check to make sure the actuator cam on the distributor is contacting the carburetor throttle shaft properly and they open and close completely! Do you have a dial gauge to set timming and a timming light, I'll give you everything you need in the way of specifications as you need them!<br /><br />Help is here,help "Tim" and I help you!<br /><br />Read & Believe!!<br /><br />Merc!!!

 

[crem1]

Re: merc500 1973

No dial gauge but the two white lines on the flywheel when aligned to TDC on the scale and the line on the pulley automatically sets the piston to TDC. As I said earlier I hooked up the timer and in forward gear, tied to the dock, I got a reading of 8-9 deg BTDC running at 800 RPM's. It coughed or sneezed a couple of times before conking out when I gave it more gas<br />Thanks Guys<br />Alex

 

[timmathis]

Re: merc500 1973

^

 

[crem1]

Re: merc500 1973

Timing is my next step. I adjusted the Idle stop screw (all the way in) and now I can start the engine with the warm up lever up and after a warm-up period I can lower it without conking out the engine. The reading in my previous submission is the result. i.e 8-9 deg BTDC at 800-900 RPM's<br />Thanks<br /><br />Alex

 

[timmathis]

Re: merc500 1973

Will it rev up to 1500-1800 RPM with the warm up lever?<br />If so check the timing then. What do you have? You want it at 34 degrees max. Tim

 

[crem1]

Re: merc500 1973

I'm going up north today and I'll give it a shot.<br />I'm assuming this is when I'm in neutral? The warm up lever does not move when in gear, right?<br />Thanks Tim<br /><br />Alex

 

[timmathis]

Re: merc500 1973

Right,in neutral.

 

[crem1]

Re: merc500 1973

Another question. If I can rev it up to 1500-1800 RPM's without the warm up lever is that OK?<br /><br />Alex

 

[timmathis]

Re: merc500 1973

I'm not sure about that. What you want is to check it at max spark advance. It should be 34 degrees. Do you know what I mean when I say max spark advance ?

 

[crem1]

Re: merc500 1973

No!!!!<br /><br />Alex

 

[timmathis]

Re: merc500 1973

Alex, If you put the timing light on #1 start the motor With the timing light on the timing marks. When you rev the motor the timing will increase at one point it will stop going up any more. That is max spark advance (usually adout 1500-1800 rpm's) That is why you can't set it at 34 degrees at a idle.

 

[timmathis]

Re: merc500 1973

Did that help you understand. What and when max advance occurs?

 

[crem1]

Re: merc500 1973

Hi Tim!<br />Timing light connected to cylinder #1 the following observations were made:<br />At 1800 RPM's it's 10-11 BTDC this was in neutral and the warm up lever up.<br />Another reading with the boat in forward gear and tied to the dock was 850 RPM's at 9-10 BTDC.<br />I'm still a little woozy about your explanation of Max Advance.<br />Right now I can actually give gas without the engine conking out while in forward and not tied to the dock. The forward gear all the way in gives 4100 RPM and I'm not travelling that fast.<br />I believe we are very close. Yes?<br />Thanks<br />Alex

 

[crem1]

Re: merc500 1973

Hi Tim!<br /><br />You must be on your long weekend!!<br /><br />Alex

 

[timmathis]

Re: merc500 1973

I have been a little busy. What you want is for the timing to max out at 34 degrees. Like when you said at 1800 rpm's you had 10-11 you should have turned the timing screw to raise it untill it was 34 degrees at 1800 r's./ and then if you could check it at 2500 rpm's it should still be at 34 degrees.<br />You never want it to go over 34 degrees. Tim

 

[crem1]

Re: merc500 1973

Thanks Tim<br /><br />Alex

 

[speete1011]

Re: merc500 1973

Alex: The outboard must be in forward gear when checking the Timming to 34 degrees spark advance<br />this could be quite Dangerous for a Novice!! 5800 RPM's @ WOT is what your looking for "Alex"<br /><br />Merc!!!