Volvo Penta 250 Poor Starting

[PaulJ6152]

I am having a problem with my twin 250's. They will start but will often just die even from high revs when cold. Once the engines are warm and we are underway they run fine and start easily. The boat is used on the river so operating at low revs most of time. Normal things checked, timing, points, plugs. What I have noticed is plugs soot up (black coating) so wonder if slow running is too rich, carbs are solex without chokes. Seems odd both have same problem. They are fed from one tank via seperate filters.

 

[alb40]

A little black is normal, anything more, then maybe you are burning a little oil? A hotter plug may help.

A friends 260 vp behaves the same, hes on the non tidal medway. A good run down and to the esturary helps clear things out, and combats possible glazing of the bores from running slowly. Maybe this is why you could be burning a little oil if that is the cause of the plugs dirtying?

Id suggest nothing major is wrong, just try a good run at higher revs under load to get the engines nice and hot for a few hours before it warrants investigating further.

 

[PaulJ6152]

Thanks, you could well be right the only problem is opening the engines up is a bit difficult on the Thames!!

Hotter plugs could be worth a try.

 

[alb40]

Why not plan a trip downriver sometime? After all, if you got a boat, might as well use it and explore the waters a bit!

 

[PaulJ6152]

Absolutely, but only got our boat last November - Princess 266, so are starting with exploring the non tidal Thames.

We have used it a fair bit already even with iot being out for a couple of months. However with many locks closed over winter it has restricted us.

My wife is into the cruising mode whereas I would love to get down to the coast so will work up to it.

This is one of the reasons for wanting to sort the poor starting out as she wants to take it out wiith her friends and is used to modern cars that start first time!

I also need to get the hang of this thing that doesnt have a footbrake and at times a mind of its own. I am sure it would happier going faster than 5mph.

But I have to say its great fun (probably more so for my neighbouring berthholders watching me)

 

[alb40]

A fast hull like the princess on outdrives wil always be a pit of a pig at slow speed, but practice will make perfect so you can moor up without any dings!

Old engines will never work as well as new. I have a small freeman in addition to a liveaboard, which has a small ford petrol engine. That always takes a little coaxing into life when you first start it, but its happy as a pig in s**t once is warmed up.

The princesses are nice boats, once you have the confinence to venture to the tidal, you'll be able to bring her into her own, shes probably quite a nippy boat with those powerful engines.

As ive said, you've got yourself a nice boat there, i hope it behaves and you enjoy yourself with her /forums/images/graemlins/smile.gif

And welcome to the forum as well!, its a useful wealth of knoledge to behold! There will also be plenty of people along the way that will help you en route to coastal cruising!

 

[spannerman]

They are notorious for being pigs to start not having a choke, you have to find the 'sweet spot' to get them warmed up, usually about 1300-1600 rpm, any faster and they fade out, any slower and they fade out. Once you find the right rpm range just let them run for about 5 mins so that they will then idle.
Then soot is indicative of a rich mixture, but I would give them a good hard run to blow the cobwebs out before you go further. Then once they are good and hot you can play around with mixture and idle settings.
Also check that the accelerator pump is working, I have had many that were seized up from water in the fuel, the easy way is to remove the aircleaner and get someone to pump the throttle you should see a jet of fuel from a small nozzle near the top of the venturi if not check the small arm on the throttle linkage that depresses a plunger on a square shaped housing, check that the plunger returns after pumping the throttle, often the plunger sticks fully in so you have no mixture enrichening.

 

[PaulJ6152]

Thanks for your ideas. I was hoping to find some people with similar experiences.

I had a feeling there was a knack to starting them as they have started and run OK but then the next time same old problem.

 

[Loupe]

As always great information from your members. Thanks