Hey Dyner68: You definitely need to consider a diffrent prop for your usage. A 23-pitch is way too much rake fore your setup. I had a 21 pitch on my 351 CID, 233 hp (2 bbl) mercruiser i/o and it had limited holeshot for the +180 lb crowd before I re-proped with a 17 pitch high-five (5-blade) and it is like night and day. Performs the same as the inboard fleet we use. I gave up approx 5 to 7 mph on the top end (still tops out around 46 to 48 mph) and the wide ope throttle rpms are at 4300 (up from 3800; your gearing may be diffrent). I have a mid-70's mercruiser outdrive so your prop options maybe somewhat limited with an eaton; may want to consider having your existing prop re-pitched at a good prop shop if you cant find an alternative (eBay may have some). Definitely consider a 17-pitch for a 302. Your hp rating is a bit exaggerated at 260 hp as the stock 302 was rated at 188 hp (probably with a 2 bbl) so see if you can reduce the prop pich (as Jim suggests) to get a bit more slippage at acceleration. Your hesitation at acceleration may also be a worn accelerator pump (mechanical plunger that shoots a burst of fuel at the point of hitting the throttle). The aluminum bore carbs don't like the alcohol blended fuels (have a perpensity to pit), especially if it sat a while. A accel pump bore honing and a carb kit may fix it but I've had better luck with changing the whole works out. Cheers, Kevin-
Kevin, You may have missed that he has a Holly carb. They have a diaphragm style accelerator pump. Holly sells all kinds of mods to that pump, and it is completely replaceable. So the options are numerous. I am thinking that he is so over propped that it cannot get into the power band right away. I also need ot look up that carb and see what size it is. I would run a 14x17 with the tip cup removed on a 1.5 gear ratio 302 Mercruiser and let it rev, but the rpm vs speed numbers he gave lead me to believe he has a much different gear ratio. That is why I want to see the max rpm for it. jim
I can't find carb number 80246 in the master list. I need you to get the number off the carb. It is located here: http://www.holley.com/TechService/ListNumber.asp edit, can you get me a close up picture of the carburetor with the flame arrestor off? (the aircleaner in auto terms). jim
I'll get you numbers for the carb and prob this weekend, but I think I found the carb here on the Overton's website as it was purchased there for this overhauled engine in the mid 80s: http://www.overtons.com/modperl/product ... 44&aID=23E The RA052002 is the number on the receipt from purchase I have a record of. Thanks for the ongoing help -- I'm confident we can get me more out of this boat -- it's so fun to drive and like no other boat I've driven. I'm reading some articles the seller collected and gave me regarding the design of this Hydrodyne hull. The editor of Trailer Boats Magazine writes in 1991, "The idea of the rounded chine was to prevent the boat from 'tipping' in a hard turn. [The roll was] part of the fun of this type of boat. You could really put the gunwale down and come around. It might unnerve some passengers, but is not dangerous." I've rolled well into my left turns, but would not try that at high speed. Would you?
That carb should not cause a bog if it is in good condition. It is now 20 years old and may need an accelerator pump. It is also possible that the idle transfer circuit is partially blocked. Does it idle OK? Work up to the hard turns slowly. jim
Let's see...engine completely overhauled in 86. The carb was purchased in 92 and a carb kit (RN0118-1) was purchased from Overtons in 96. Low use since this restoration, but time has passed -- you're right. And by "overhaul," we're talking block dipped and cleaned, heads decked, crank polished, rods checked, new rings/bearings, new cam and springs, new hardened valve seats for unleaded gas, new Milodon lifters, valves and seats lapped, new impeller, new fuel pump, new Edelbrock Performer "2121" dual plane aluminum intake manifold, new marine hoses/clamps everywhere including those to the lower unit, new Salisbury mufflers and exhaust (much noisier than original I might add), new plugs/wires/Excel SuperCoil)/condenser/etc, and new engine mounts. Sorry...the answer to your question is that it starts and idles great. Takes about 5 minutes to warm up though.
Hey Folks: Focus on the prop, and then go after the dead spot in the acceleration. I've had the privilege of skiing many different setups and the ones that have the right hp to prop pitch are always favored over those with speed prop setups. A ski friend has a 165 i/o with a 19-inch pitch and it's pretty worthless for anyone over 180 lbs. I'm looking to replace her prop with a 17-inch also If you have a need for speed, keep the prop you have and search out a prop that is compatible with your outdrive and have it re-pitched to 17 inches. I've got two props on the shelf of the garage and one on the boat, never hurts to have a backup along if the favored prop gets messed up. Speaking to the acceleration issue, Jim, I've rebuilt two Rochester’s with the same symptoms but believe that any aluminum cast carb can have pitting issues if the boat has sat. The accelerator bore gets pitted from oxidation. It’s a function of both the type metal (aluminum) and sitting; the oxidation not only pits the bore surface but wears down the plungers as well. Even with a light honing and new plungers, the rebuilt carbs that I've had done have developed blow-by (fuel by-passing the plunger and not going into the throttle body). Rebuilding the accelerator pump is relatively easy but the results have been very frustrating and a big waste of time in the end. A new bowl assembly may negate the purchase of a complete carb; personally, I stay away from the rebuild kits if the acceleration pump bore is the issue. One last contribution, I've attached a pic of a completely stock 1968 that I came across for sale a while back with the same pylon that you have. Tom Miller may be able to shed some light on the strength but your pylon appears to be correct for the production period (i.e. came with the boat). The seats look to be aftermarket though. Enjoy the boat; the bugs that have popped up are relatively minor. Kevin-
The Holley has no accelerator pump bore or plunger. The pump is a diaphragm style and the whole pump is a replaceable unit. It sits on the outside of the body. You can see it in the picture. It is the round thing just above the electric choke. With the rpm vs speed he quoted he may have a gear ratio over 2 to 1. A 17 would turn 6000 wide open with that. I would like to hear his max rpm before making a pitch recommendation. When my boat was a 302 I/O I had about 5 props for it. I had a 16, a 16-1/2 and several 17's in different styles, but it had a 1.5 gear in it. jim
Good pics. I recall seeing that boat online from Texas as well last Fall/Winter when I was shopping. I'm pretty sure it's a 69, which is a year newer. Very similar but I'd guess that's when lights were added and I recall this engine in this one was smaller (at least as advertised). I would also guess the windshield was an easy add-on at that time as well. You're correct that my seats (especially the back ones) are after-market. The gas tank of 68-69 was in the back and mine was rebuilt and relocated to the front. This modification allows the rear seats to pop out on both sides of the engine to store ropes and jackets while my young girls each have a fun place to sit. Jim--note that on this one, it has the same smaller air intake hole in the rear like mine w/o the grill like in the front. Leads me to conclude it never had one and I'm good to go as-is.
There is more information I need to get to the bottom of which prop to get. The Volvo 200 has two different prop shafts show in the pictures below. I need to know which you have. In the picture your prop looks like a left hand rotation which would be counter clockwise when viewed from the rear to go forward. If you take a picture of the prop close up, that would help. I would really like you to remove the prop and take it to a prop shop and have them measure the pitch. Some of the numbers you gave don't make sense to me for a 23 pitch. So I need: Full throttle rpm Picture of the prop Identify the prop shaft Prop pitch--it may be on the hub of the prop as a dash number in the part number, but measuring is better. Thanks, jim Maybe we can get this settled with one trip to the boat.
