aq170 w/ 3 solex carb question??

[billgabbert1]

My problem is when my boat is in gear at about 3000 rpm?s after a couple of minutes I can feel a lost of power then it will pop through carb. I can let it idle for a min or so then give it more throttle and it will do the same again after a couple min. When have it at 2300 rpm?s then It will almost stop but still will lose power and pop once in a while? My thinking is that it is starving for fuel and when it is idling it can fill up the fuel bowl ? maybe a improper adjusted float ? Or fuel pump isn?t pumping enough fuel? Also I don?t think that the carb are synchronized properly can this make this happen? It is a AQ170A with 3 Solex 44 pai carbs

Thanks for the help

 

[captmello]

Re: aq170 w/ 3 solex carb question??

I think you're on the right track with fuel. I'm not sure where to start, but I'd go through the entire fuel sytem and check all the usual parts. Filters, pickup tube, fuel water, carbs,...

The OEM manual has some info on the carb syncing. You can download it in the volvo penta info, from the adults only sticky. Thanks to Don S.

I would try these one at a time until you find the problem.

Let us know how it goes.

 

[PiratePast40]

Re: aq170 w/ 3 solex carb question??

Sounds like the carbs need a good cleaning. They don't seem to like varnish and gunk.

You can go a long way towards syncing the carbs by matching all the throttle plates and accel pumps to see that they all actuate the same amount with throttle advance. I'm getting the impression that true syncing is as much a secret art as anything else. Unisyn tool on top of a coffee can seems to be the most popular method to do it the right way.

You've got all of the other suspicious actors to rule out as well. Points, rotor, cap, wires, and plugs all in good shape? Timing advancing as it should? Compression on a 35+ years old engine is allways something to check out. Dragging around a couple of bad cylinders can also keep you from getting up to full rpm.

Just noticed you were in Eureka. I was down there last week. Was thinking I was escaping the Oregon wet weather but it doesn't look like Humbolt Bay is much different that our coast up here .

 

[billgabbert1]

Re: aq170 w/ 3 solex carb question??

Ok so today I decided to check the timing because I just got my hot spark in to change it from points to electric ignition so I seen that the timing was at 50deg. Advanced so I timed it at 2000 rpm at 29 deg advance and it was a lot better but still would lose power and pop not as often. So one time when I felt it starting lose power I tried to give it more throttle and it did nothing at all it was like I didn?t do anything ? I think that it still might be fuel or maybe needs to be retarded a little but I have a book says that 28-30 at 2000 rpm?s?

After doing this I pulled new spark plug that I installed yesterday all looked good but #1 had burnt off electrode all the way? Maybe from being too advanced ?

Yea pirate last week was not the best weather here on Humboldt bay today is nice about 60 or so fairly calm ocean yester was nasty. Crazy weather great fishing salmon season opens on sat hope to go please help me I want to fish!!!

 

[PiratePast40]

Re: aq170 w/ 3 solex carb question??

You don't set it at 2000 rpm, you set it at idle and the weights advance it that far. Without a Sun machine, the best you can do is observe that the timing does in fact advance as rpm increases.

The Hot Spark module needs a coil with at least 1.5 ohms internal resistance. If you didn't buy a coil from Hot Spark, and stil need one, a decent auto parts guy can hook you up. Read the troubleshooting section on their web site to see what specs you should be looking for. I believe your engine had a starting resister in the system - it talks about it in the manual. You may not need that with the new coil with internal resistance but I believe that may be a key to your issue of a burnt electrode on a spark plug..

The problem with an older boat and engine is that you just don't know for sure about anything until you actually check it out. You might have an old fuel hose that is deteriorating from ethanol, might have a rusty anti-syphon valve, might have junk in the tank clogging the fuel pickup or, might have a clogged fuel tank vent. Could be that your spark arrestors are dirty and plugged, etc., etc. I think you know where I'm headed - you have to verify everything. Just remember not to cross the wires on the Hot Spark. Only takes a second and you'll be ordering a new module. :redface:


We had supper at the Marina in Humbolt Bay - great food. Saw one of the local "swimming fishermen" around the commercial boats. Up on the upper Willamette and on the Columbia, more than a few people would be greeting them with a 30.06. Even the Marine Board is hazing them with firecrackers to keep them away from the dams. Hope you guys have a commercial salmon season this year.

 

[billgabbert1]

Re: aq170 w/ 3 solex carb question??

That?s funny just got home from dinner at the marina. I checked the coil out I got 3.5 Ohms resistance they said i needs at least 1.5 so thats ok. i'll check the timing at idle like you said.

 

[billgabbert1]

Re: aq170 w/ 3 solex carb question??

well i got it going just got home it was pouring rain but the boat ran awesome !!! i put a colder plug in it ngk bp8hs and put timing at 12 deg advanced and synced the carbs.

thanks for all the help!!!!!!

 

[billgabbert1]

Re: aq170 w/ 3 solex carb question??

oh yea and cleaned the spark arrestors

 

[PiratePast40]

Re: aq170 w/ 3 solex carb question??

Glad to hear it's running right. Weather is supposed to be good this weekend - good luck with the salmon fishing!