Top speed???

[biggsie]

Motor is strong, good compression, new ignition/carb Maybe I'll
Just deal with it and call it good.


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[2500HD]

If you don't have a back up prop i would suggest getting a acme 541. Atleast that is what i think it is. Having a spare prop is awesome. It can be the difference between an awesome weekend on the lake or not. Give Nettle's a call, They will get you set up.

[biggsie]

What's a normal top speed? I would like to see at least 40.


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[ckracing]

Even with the stock prop - 13x13 3 blade, you should see more speed and RPMs. My 86 on stock prop WOT with just me was 42 MPH on calm water. When I switched to an Acme 541 I gained top speed (44) and felt a large improvement in holeshot. By far the prop swap was the most notable performance improvement for the $.
Only engine modification from stock I have is an electronic ignition (Petronix), better plug wires, new Holley 4160 carb.
Good luck!

[biggsie]

Maybe I should experiment with a prop swap? Or at least check the # on the current one.


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[SUPRA_ALLEGRO_LANE]

WOT I'm running 46 mph at 3900 rpm. That's with 2 bigger guys in her too.

[lively]

Whooahhhh . So are you for sure it's WOT ? Have you checked the linkage at carb and make sure it's adjusted for full throat ? What about timing ? I have a 351 with a 1:1 and a 13x13 L prop and at WOT on smooth glass 4200 rpm I'm about 40-43 on GPS depending on how much beer and babes are in the back


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[chris young]

I haven't posted my specs in the sticky thread yet because I still have not been able to calibrate my tach since I overhauled it and I'm pretty sure it reads low.

Non the less, Acme 541, 1:1 me alone in the boat 39 MPH smart phone GPS @ WOT. My tach reads 3400, but as I said I don't think it's correct. Basically the same boat as yours, (84 Rider) PCM 351 Holley 4160.

Do you still have your exhaust mod installed? I've heard the factory one takes away one or two MPH and if yours doesn't allow the motor to breath properly, that could cause issues as well.

[biggsie]

I will look into the throttle linkage today. Speed was with no passengers, 7/8 tank of fuel and GPS app on my phone. I do still have the PVC exhaust on, maybe I'll drill out some rivets and try it. Would running without traps or flaps cause an issue ??

Ign timing is another story.... Damn timing light is making me mad, I can set idle timing to 8-12 deg but my attempts at checking the advance at 3000 rpm are not working. Maybe the dist is bad but it seems to run so nice..... I did some on the water timing tuning the other day and I forget where I left it but close to 10 deg.


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[chris young]

Timing makes a huge difference, so if your dist is not working right that could most definitely cause issues. I bought one of these http://www.ebay.ca/itm/E5JL-12100-CA...vxp=mtr&_uhb=1 and these guys are great to deal with.

Would running without traps or flaps cause an issue ??

I don't think so, mine's been running with wide open exhaust since I bought it. I'm planning on some type of FAE setup myself so I haven't bothered with flappers or traps.