good flow from a gm20f

[adamtroyg]

Hi everybody,
thanks for all the good advice in the past. hoping for some more.
purchased a 1973 Sabre28 with a 2003 yanmar 2gm20f last fall. i don't feel i have the "flow" of sea water with the exhaust that i remembered. the flow varies from a trickle to almost nothing with a occasional belch of a few ounces at idle. at higher rpm it's just a splashing spray. don't know why but i though it should be more constant like a hose running.
yesterday i cleaned out and flushed my strainer, changed my impeller, & took the heat exchaner off & cleaned all the thin tubes rinsed. when i put it all back together and ran the engine, i wasn't impressed. the only things i haven't check: the elbow that introduces the heated sea water to the exhaust & inspect each piece of rubber hose.
is the flow i am seeing normal? any ideas of other parts to check/clean/replace ? i haven't overheated yet ( shouldn't have said that )
thanks again everyone. . .
adam

[SVCetacea]

I have the same engine. I get a "belch" every 2 seconds or so at idle and a constant flow at higher rpms. Did you check that the thruhull isn't blocked?

[adamtroyg]

should have done that this weekend ( was really hot ) going to make a good diving mask part of the permenant gear on the boat.
next time i'll be taking all the hoses & the elbow off and checking them for blockages.
spoke with a yanmar tech guy today, he said to put an oven thermometer on the engine near heat exchanger & the thermostat. he said it can run well in the 160F's, but the buzzer & idot light will signal at around 200F.

[bubb2]

I have same the engine, at idle I get a quart every 2 sec or so as the revs come up I get a solid stream. I hope this helps.

[DrB]

I have the 30GM model and at idle get a little less than a pint or so every few seconds in spurts. At cruising speeds, the flow is consistent and I would say a quart or so every 5 seconds. In a minute, I can almost discharge 5 gallons (measured on the hard when recommissioning the engine in the spring) at 2000 rpm.

DrB

[adamtroyg]

wanted to thank everyone again for their input. tonight i went to the boat after work. figured i'd start at the begining . . . took the hose that went to the strainer off and could see daylight through it. opened the sea **** and barely got a trickle. using a coat hanger produced a piece of seagrass. the top of the seacock has a reducer with a 90degree bend to it ( to avoid making contact with the exhaust hose) the plug of seagrass that i removed from the reducer looked like a large cigar but. opened the sea **** again to let clean water run . put it all back together and ran the engine ,& saw the flow i expected to see. there was no one at the marina to go out for a sail with, so i went across the bay to Seaside Island and surfed 'till dark.
pura vida !