2.1L Volvo- Carb "restrictor" plate?? Other questions too- Deiselling!

[Danwec]

I have a 1984 18.5ft Bayliner Capri Cuddy w/ the 2.1L Volvo engine.
It runs decent. It's been very well taken care of (Grandpa has had it since new, we are the only owners, and it's now mine).

It's a little tired, and sometimes diesels after running. That is usually attributed to carbon buildup. I'll try some engine cleaner/decarbinizer.

Does a top end of 30mph and 4900 rmps sound about right? I would have thought it should run at least 35.

One cylinder has compression about 15 psi below the others.... do those "compression restorers" that you add to engine oil work??

Last question.... when I had the carb off for a rebuild, I noticed that there is a plate on the base of the carb that protrudes quite a bit into the throat of the intake, almost a full quarter of it. Should this stay on? It is a definite restriction, but maybe it's there for mixing reasons?? Anybody else seen this?
Thanks!
Dan

 

[Don S]

Re: 2.1L Volvo- Carb "restrictor" plate?? Other questions too- Deiselling!

What's the model number of the engine. Volvo doesn't list their engines as 2.1L

Volvo Engine ID Service Bulletin

 

[Danwec]

Re: 2.1L Volvo- Carb "restrictor" plate?? Other questions too- Deiselling!

Sorry, AQ125.

 

[Don S]

Re: 2.1L Volvo- Carb "restrictor" plate?? Other questions too- Deiselling!

15 psi compression difference is not a big deal. But what is the actual compression readings?
Don't go feeding that engine some "Restorer medicin" that is something people use to Temporarily mask a problem till they can sell it to some unspecting buyer, not for long term repairs on an engine you want to keep.
Have you done a full tuneup lately? Points, condenser, cap, rotor, set the dwell, then set timing, and check advance timing, adjust idle mixture and idle speed. Any one of those could cause the dieseling.
What is the engine temp when you run it. Should be around 190?. Higher could cause dieseling, how old is the impeller? It's another maintenance item.
They do have a flange between the carb and manifold that must be there. Make sure it's on there in the proper direction. Should be an arrow on the flange.

 

[Danwec]

Re: 2.1L Volvo- Carb "restrictor" plate?? Other questions too- Deiselling!

Thanks a lot for the help, really appreciated!
Yes, temp is steady @ approx 180. That was my first check. Points, condenser, timing, cap and rotor have all been replaced and set by me in the last year. I have to change the plugs, and do a reading on the old ones.

SO- keep the plate in place. Will do. I'm assuming it evens out fuel flow to the individual manifold runners.

30mph seems a little slow to me though. Fresh anti foul, no growth, and the prop is about an 7/8 out of 10.
I just did the idle mixture and speed. It hunts for rpms a bit though, and could be a bit smoother.

Dwell? How do you actually set that? I'll admit I never have.

 

[ricecakes01]

Re: 2.1L Volvo- Carb "restrictor" plate?? Other questions too- Deiselling!

Thanks a lot for the help, really appreciated!
Yes, temp is steady @ approx 180. That was my first check. Points, condenser, timing, cap and rotor have all been replaced and set by me in the last year. I have to change the plugs, and do a reading on the old ones.

SO- keep the plate in place. Will do. I'm assuming it evens out fuel flow to the individual manifold runners.

30mph seems a little slow to me though. Fresh anti foul, no growth, and the prop is about an 7/8 out of 10.
I just did the idle mixture and speed. It hunts for rpms a bit though, and could be a bit smoother.

Dwell? How do you actually set that? I'll admit I never have.

I have the same boat and around 30-31 is all I get out of mine at about 4400 rpm.Also do you happen to know the best prop for that boat?

 

[Limited-Time]

Re: 2.1L Volvo- Carb "restrictor" plate?? Other questions too- Deiselling!

ricecakes01,
Tacking your question on to a year old post is not a good idea...........................You're far better off starting your own thread.................and for your prop question I'd head to the prop forum....................BTW welcome aboard.