volvocobra
Recruit
- Joined
- Jun 2, 2010
- Messages
- 2
okay, i have a volvo penta with a gm 3.0 freshly rebuilt with new pistons, bearings, cam, valves, springs, manifold and elbow etc. i reused all ignition parts and carb, but rebuilt the carb, which is the holly 2 barrel stock carb. outdrive is stock omc/ volvo penta cobra. my problem is the motor feels sluggish, it revs up great with no hessitation in neutral, with 2 people on the boat it gets right up out the water and will run untill the tach hits 3800 (no speedometer). it will not go any higher than that even at full throttle. but when i have someone skiing behind the boat it has alot of trouble getting out of the water even at full throttle, when it finally does (after about 10 to 15 secs of full throttle) it goes ahead and speeds up like it is supposed to. but i feel that 140 hp should shatch a skiier right out of the water. so i checked multiple things (accel pump, mains, linkage, and finally the distributor). i do not have the volvo penta special tool. but hooking the timing light up at 900 rpm in neutral it has 8 btdc when i put the trottle at 3500 it only goes up to 12 btdc. for me this says that something is wrong with the ign module. so i replaced but had no affect. after reading some replys that Don has made to other people i downloaded the ignition system troubleshooting for the delco est 3.0 pdf file. and see that my degrees are not the same as the chart at the end of the pdf. the only other thing to replace in the distributor is the pickup, but it almost seems to me that these distributors dont have enough advance built in them to start with, with 4600 on the chart only supposed to have 21 degrees... and my motor does not even see 4600 in gear. maybe not relative but my 4 cyl volkswagen has 32 degrees total advance at 4000. so i was thinking of maybe trying the mallory replacement distributor i found on ebasic power. but cant find any total advance specs on them, and i dont want to replace if the curve is just going to be the same as mine. maybe someone who has more experience can offer some suggestions to help get all the power to the prop.