I think carb problems on 83 Volvo AQ125A

[wapitiguide]

I have a 1983 Bayliner Capri with Volvo 125a/270 Stern drive. I have been trying to get this boat to run. I have rebuilt the carb, replaced the plugs, points, cap, rotor, wires. I have set the points to about 62 degrees. When I try to time it I can't get it to the 10 degrees. When I do it will run but very crappy. When there I have adjusted the idle mixture both ways and the idle screw but still don't help. So when I get it to run decent it is set at about 40 degrees. When there it will idle great but I can't get it rev to higher RPM's. I also checked the coil with a digital multimeter. resistance on the small connections is 3.2. Resistance from the small to the coil wire plug in is about 9.62. I am at my wits end and my wife is tired of me putting money into a sinking ship. Any help tp get it running would be great, if not I might be forced to sell the thing and not really wanting to do that. THANKS IN ADVANCE FOR ANY SUPPORT.

 

[wapitiguide]

Re: I think carb problems on 83 Volvo AQ125A

I was just checking the cost of converting to the electronic ingition as well. Is this worth the expense? I really don't want to convert to this unless I can figure out how to fix the problems that I have right now.

 

[Mullin]

Re: I think carb problems on 83 Volvo AQ125A

What are your rpms when at 40degrees?

I would reset the carb screws to stock position. Adjust later when you have it running and warmed up.
You set the gap and dwell on the points?
Did you check the timing marks on the cam and crank? The belt can just a tooth pretty easy if the tension gets a little loose.


Check out this thread, this guy had a similar problem: http://forums.iboats.com/showthread.php?t=534317

I copied this from Don, thanks Don!

Here's a link to the REAL service manual.
http://www.4shared.com/file/89797330...ce_Manual.html

AQ125A timing specs, page60:
10? BTDC 0?12.5 r/s (0?750 r/m)
36? BTD 70 r/s (4200 r/m)

carb screws are on p.19
idle crew, make contact and then another 1.25 turns
mixture screw, screw all the way in till just snug, then screw back out 1 turn.

I installed a hot-spark kit, I really like it.

Once you get it running and timed at idle, the "I punch the gas and it died" thing is usually the adjustment on the accelerator pump (in conjunction with the timing and mixture).

 

[wapitiguide]

Re: I think carb problems on 83 Volvo AQ125A

Tried going to the link for the REAL service manual and it said that it is not a valid link.

 

[Maclin]

Re: I think carb problems on 83 Volvo AQ125A

62 degrees or 70% dwell is correct. Set that then set timing, sounds like you did all that.

Check the mechanical advance in the distributor, you should be able to turn the rotor in the direction of the distributor rotation slightly and have it spring back when let go. If the rotor does not do this then the mechanical advance is stuck and you will not be able to get good power, revving will be slow and limited.

Wondering also if your plug wires on the cap are in correct order and also that #1 is about where it should be.

Be sure you are looking at the correct timing marks also, not a false line on the hub or something!

 

[Maclin]

Re: I think carb problems on 83 Volvo AQ125A

Regarding the electronic ignition conversion, I would get it running in top shape in stock form first then when you convert it will just get better and not be a bandaid and mask other problems.

 

[Mullin]

Re: I think carb problems on 83 Volvo AQ125A

Weird, don't know why that link isn't working now. But I just uploaded the manual here: http://www.scribd.com/doc/94969381/Volvo-AQ125-145-a-B-Service-Manual

I don't know what problems an electronic conversion kit could mask, but if you have new points and condenser already (and know how to set them properly) the conversion kit won't do anything for you. The benefit would be the points won't move around, corrode, or need adjusting again in the future. For me, I don't have a dwell meter and wouldn't know how to use it if I did. So buying the $50 kit instead of new points and a meter was an easy choice for myself. Here's a tip, if you buy the hot spark kit, you need thermal paste (TIM) that is not included in the kit. Just a heads up.

If you can get it to stay running as is. Then fist check the dist is pointing at cyl #1 when at tdc. Then double check the firing order, 1342. Then start it up and wait until it is warm, 180degrees. Adjust the idle screw to get your rpms at 750. Check the timing with a light. If your crank pulley looks like mine, you might "highlight' the actual timing mark with a sharpie or a grease pencil. At 750rpm, timing should be at 10 degrees. Once you get that good, check the centrifugal advance by running it up to 4200rpm and checking the timing again to be at 36degrees now.

You know, if it wasn't for having to take off the heat exchanger and sea water pump, because something always ends up leaking, I would just say start over. Line up the pulleys yourself, put on the timing belt, re-install the dist., fire it up and adjust the ignition timing. It should be that easy.

 

[wapitiguide]

Re: I think carb problems on 83 Volvo AQ125A

Replaced the points...again an dput on a new coil. Runs like a champ. Now it overheats but think that is the impellar. Gonna replace that tomorrow and see. Runs perfect at 3000 rpm but once i go faster it starts to overheat.

 

[leakywire]

Re: I think carb problems on 83 Volvo AQ125A

Replaced the points...again an dput on a new coil. Runs like a champ. Now it overheats but think that is the impellar. Gonna replace that tomorrow and see. Runs perfect at 3000 rpm but once i go faster it starts to overheat.

A common issue of overheating during higher rpm is the water inlet hose connector under the tilt bellows, this hose fits to a curved outlet looking much like an auto thermostat cover - this is underwater during slow motion but once on plane this lifts out and when correoded allows air to enter the inlet and the water flow is reduced drastically resulting in overheating. It is located in an akward spot but isn't everything in marine mechanics? To gain access you have to remove the helmut pivot and turn the drive to loosen the clamp - slide the hose into the transom exposing the area of corrosion concealed by the hose itself.
The seawater pump is fairly easy to service, while withdrawing the pump be careful to catch the rubber blocks and drive key - at assembly time each of these must be back in place exactly the same or you will be talking like a sailor.