AQ170 Keeps creating sooty plugs, any ideas please?

[boatingmark]

Hi all

Please can someone give advice on how to correct this problem, after short use the plugs are sooty meaning its a nightmare to start.

Perhaps the carbs need overhauling?

Thanks in advance!

 

[Bondo]

Ayuh,.... Usually, soot comes from runnin' way to rich, so, Ya, it's more than likely a Carb Problem,.....

 

[boatingmark]

Ayuh,.... Usually, soot comes from runnin' way to rich, so, Ya, it's more than likely a Carb Problem,.....

Thank you Bondo, you can still get carb repair kits for these engines although i think all their made up of are new gaskets and washers.

Do you know the most likely cause of it running too lean, a possible air leak?

It can be a pain to start sometimes on cold and often need to adjust the idle screws.

The engines old but still seems good, theres good compression but needs tlc and the carbs need tuning.

 

[jerryjerry05]

You need to include a year or if it's a A B C model.
They used 7 different carbs.
​Any tags or #s on the carbs?

It sounds like you need to adjust the air screws.
Start with clean plugs and turn the screws out 1 turn to begin.
Then turn them in or out until it runs smooth at idle.
Needs to be warm and if possible in the water.

 

[boatingmark]

You need to include a year or if it's a A B C model.
They used 7 different carbs.
​Any tags or #s on the carbs?

It sounds like you need to adjust the air screws.
Start with clean plugs and turn the screws out 1 turn to begin.
Then turn them in or out until it runs smooth at idle.
Needs to be warm and if possible in the water.

Thanks Jerry

It is a AQ170C, i will look at the carbs next time im at the boat, I know their Solex possibly 44pa1?

Struggling to start the engine at the moment and unclear why, its still pretty cold here in the UK which probably doesnt help matters. Ive had to prime the carbs with fuel manually in the past.

Silly question but just to be clear you turn the idle screw anti clockwise to increase idle right?

Do you think stripping, cleaning and rebuilding the carbs would help improve things if the sooty plugs continue?

thanks

 

[PiratePast40]

If those are the Solex PAI carbs, the mixture screws only adjust idle mixture. Sounds like the carbs could stand to be thoroughly cleaned and resealed. I have the 4 cylinder version of your engine with 2 carbs and that's what I've done with mine. It's a bit of a pain to get the carb flanges bolted to the manifold properly so it takes a bit of patience. Most rebuild kits come with the gaskets, idle jet, float bowl check valve, diaphram and spring, and some of the crush washers.

As far as hard starting when cold, they don't have chokes so they're pretty cold blooded. Keeping everything in properly tune is your best bet for easiest starting.

 

[boatingmark]

Thank you piratepast40

It really is hard to know where to start but i guess one thing at a time, its certainly a learning curve!

I think thats the route ill go down and buy repair kits if i have no joy with adjustment alone, do these look like all i need to do the job?

http://www.ebay.co.uk/itm/231600060167?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

Im also going to buy a tool to check the air flow into each carb.

 

[jerryjerry05]

The idle is adjusted with the linkage.
​Not the air screws.
Pics of the carbs and linkage.
Volvos are notorious for cold starting.
IF??? the fuel system is ok.
The fuel can flow back into the tank and sometimes they need to be primed??
I turn the key all the time pushing the throttle back and forward until it starts or coughs.
If you push the throttle forward it's supposed to hit the accelerator pump and squirt a shot of fuel into the throat of the carb.
Sometimes it might help using starting fluid??

 

[boatingmark]

The idle is adjusted with the linkage.
​Not the air screws.
Pics of the carbs and linkage.
Volvos are notorious for cold starting.
IF??? the fuel system is ok.
The fuel can flow back into the tank and sometimes they need to be primed??
I turn the key all the time pushing the throttle back and forward until it starts or coughs.
If you push the throttle forward it's supposed to hit the accelerator pump and squirt a shot of fuel into the throat of the carb.
Sometimes it might help using starting fluid??

Thanks Jerry

Because there are 2 screws on each carb I assumed one was idle and one was air/fuel mixture, looks like ive been adjusting the air and fuel rather than the idle then when struggling to start the beast!

I tend to remove the carb cover and watch to see if there is fuel reaching each carb when priming, sometimes it can take ages pumping the throttle, sometimes I tip fuel in manually then crank over which helps.

Ive just brought new points and a vac-syc tool, hope to fit the points this weekend! Does anyone how the gap for them please???

 

[HorizonblueDK]

Here is a manual on the Solex 44PA1. It describes how to set and synchronize the triple setup. It's not really necessary to use a vac tool. I have followed the procedure for my AQ170 and it works fine.

http://c10300039.r39.cf2.rackcdn.com/44pa1.pdf

But off course, now that you have the tool, you can use it for checking. Be aware that the carburetors each have a J-tube, that is in the way, for using an ordinary vac gauge. An adaptor must be used.

 

[boatingmark]

Thank you horizon, very handy to have this info!