A slight knock

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jdeitz1979

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Turned 250’ish miles yesterday. Rode relatively hard, since I was with a fellow vmax rider. On the way home, just about every light was an 1/8 mile run for us...lol. Did a lot of hard riding and high rpms... until that last light. Never fully caught the shift, and with that twist, I knew almost immediately that something wasn’t right. I never looked down to see what rpms went to, but I know it was no bueno. It was two miles after that light it was parked. Doesn’t feel like the same bike, and has a slight’ish knock I can hear it more at low rpms. Monday I’ll pull my valve covers off and check timing chain, and timing, then do an oil psi check, but does anyone know the warm psi number? 10-12, or less? I wanted to make Poags hole this year on the bike.. on the 19th of this month.. I might not make it I guess




e30d466b6f6cc3865e2ca2ef1a74ae38.jpg
 
Could be the conn rod #3 & big end bearing, a known weak spot.
 
I’ll be diving in Monday after work to see what’s there. I’ll start with the filter, that’s definitely a good spot to start. I’ll get a video of the noise


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That isn't looking good. Mining for gold means that engine is done. You can salvage the heads/cams and trans but the rods, crank and block are shit. I do have some options and you can email me if desired.
 
I'd take Sean's advice, he's said in the past when it ruins a crank bearing surface or the big end of a rod, the block doesn't seem to last even-if you rebuild it with good replacement parts, nor the crankshaft.

Guessing what that really-big pair of pictures is, is the oil filter?
 
FM, I pulled the oil filter and used a clean container to catch the oil. The oil in the container is what’s pictured. I remember reading that as well about Sean’s rebuild notes.

Sean, I don’t think the gold in my pan is paying as much as I’d like lol. There is a guy here that has a good motor for sale I’m more then likely pulling the trigger on, miles are high but it will keep me riding this season and more to come if I keep the needle out of the red. If I need anything, I won’t hesitate to email you.


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Just out of curiosity, what is the hp gain with a venture 1300 vs vmax 1200?

And what are the 5th gear gain mph vs rpms


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Approx 10% gain.
Ratios are very similar with only a few MPH change in 1st and 5th
I can give you a spreadsheet with the ratio info and gearing affects. Another note, the Venture (86-93) trans has the same 2nd gear design as the "recalled" 85 Vmax trans. We've used them with no issues but it is a possible failure point.
 
Approx 10% gain.
Ratios are very similar with only a few MPH change in 1st and 5th
I can give you a spreadsheet with the ratio info and gearing affects. Another note, the Venture (86-93) trans has the same 2nd gear design as the "recalled" 85 Vmax trans. We've used them with no issues but it is a possible failure point.



That 10% puts it at 130hp? If a good running vmax engine can dyno in the 120’s

I figured there would a little better rpm vs mph ratio, is that better suited with the venture dif or with the vmax dif.


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The Venture diff just helps reduce cruise RPM's at the sacrifice at acceleration (some may disagree).
 
While I've not got anything like Sean's experience, I've never seen a stock VMax break 120 RWHP in any of the American magazine road tests.

With a pipe and carb tuning, sure, something in the 120's is possible, many have done it.

If you can locate a 1300 cc Venture, I think that probably is the easiest way to boost your HP via more displacement.

Running a 17" rear wheel will give you back the acceleration that the Venture gearbox takes-away, because of it's shorter height/wheel & tire diameter.

That 10% puts it at 130hp? If a good running vmax engine can dyno in the 120’s

I figured there would a little better rpm vs mph ratio, is that better suited with the venture dif or with the vmax dif.


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