1970 Stevens semi v

436 Views 12 Replies 6 Participants Last post by purpledragon, 5 d ago

Budweiser

Been a while. Missed you guys.

I recently had a family friend reach out and offer me the family boat they custom ordered from Stevens in 1970. It's a pretty unique boat. It's a semi-v, F-N-R toploader, factory custom engine cover/hatch, 1969 L71 427, and is in fairly good condition. Cav plates are non adjustable, other than turnbuckle adjustments. 99% of it's water time was on Lake Arrowhead in Southern California and I'm told that's why they ordered the semi V bottom, for Lake Arrowhead's often choppy water conditions. The other 1% of water time was on the Colorado River.

Couple questions:

Do any of you guys know if I can get by with 91 octane fuel and just retard the timing a degree or two, or should I be running 100LL (or similar) fuel in this engine? 1969 L71 427, 11:1 CR.
What issues may occur if I run a few hundred gallons though her this summer with these fiberglass tanks? How prudent is it to get rid of the fiberglass fuel tanks?

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Mouzer

· #2 · 9 d ago

havent leaked in 53 yrs dont leak dont know what 1 more summer is gonna hurt check for blistering leaks or smell change em out next winter my 2 cents

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fc-Pilot

· #3 · 9 d ago

The 100LL won’t eat the tanks. Run that as it will save you from needing tanks. Then you don’t have to worry about timing issues.

Paul

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SPECTRA-SANGER

· #4 · 8 d ago

the issues will happen when the gas sits in the glass tanks, run and use it!

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Budweiser

Discussion Starter · #5 · 8 d ago

Guys, thanks for the responses. Since posting this thread, I asked the previous owner (77 year old gentleman. It was actually his dad that ordered the boat new.) what they used for gas and he said whatever they sold at the fuel dock on Lake Arrowhead. Lake Arrowhead is 5200' elevation. I also asked if he jetted/tuned the carb at all for elevation and whether they put different jets in for Lake Havasu/Colorado River and he looked at me with a blank stare and said his dad took care of that sort of maintenance... so who knows. He also said they took it out a couple years ago. But, the last tags on the boat are 2001, even though it's currently registered. My guess is it sat in the garage for the past 20+ years without any use. I guess I'll just drain any remaining fuel, refill with 10 gallons of premium (91 octane here in CA) and give it a close listen while running. If it pings, I'll retard timing until it doesn't.

Half of me wants to just pull the engine, sell it to someone looking for a genuine vintage L71, and put something a little more modern (pump gas friendly) in it.

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fc-Pilot

· #6 · 8 d ago

Think about pulling the engine next season. Get on the water and have some fun. Enjoy my friend.

Paul

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Budweiser

Discussion Starter · #7 · 7 d ago

fc-Pilot said:
Think about pulling the engine next season. Get on the water and have some fun. Enjoy my friend.

Paul

That's a good plan. I'll put fresh oil in the engine, a new impeller, figure out whether the puddle of clean looking gear oil in the bilge is a spill someone didn't clean up or if the v-drive seals need to be replaced, put her in the water, see what I see, and enjoy the summer months. With a little luck, I should have a trip report in a week or so.

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Mouzer

· #8 · 7 d ago

mine runs 93 octain no problem out here was running 110 vp race fuel in cali now out here i just run 93 oct

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Budweiser

Discussion Starter · #9 · 6 d ago

A little help, please...
Is this a Neovane V755? I've only seen them cam driven before. Can't seem to get a camera angle that shows a model number.

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Budweiser

Discussion Starter · #10 · 6 d ago

Dope!... I just noticed the "755" in the casting on the last photo. I was too focused on the sticker before. Impellers ordered.

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Teamseal

· #11 · 6 d ago

Very nice v-drive. throw $10k in service items and updates and run it another 50 years!!

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Budweiser

Discussion Starter · #12 · 5 d ago

Shoot... in 50 years, an oil change will be $10k

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purpledragon

· #13 · 5 d ago

Budweiser said:
Guys, thanks for the responses. Since posting this thread, I asked the previous owner (77 year old gentleman. It was actually his dad that ordered the boat new.) what they used for gas and he said whatever they sold at the fuel dock on Lake Arrowhead. Lake Arrowhead is 5200' elevation. I also asked if he jetted/tuned the carb at all for elevation and whether they put different jets in for Lake Havasu/Colorado River and he looked at me with a blank stare and said his dad took care of that sort of maintenance... so who knows. He also said they took it out a couple years ago. But, the last tags on the boat are 2001, even though it's currently registered. My guess is it sat in the garage for the past 20+ years without any use. I guess I'll just drain any remaining fuel, refill with 10 gallons of premium (91 octane here in CA) and give it a close listen while running. If it pings, I'll retard timing until it doesn't.

Half of me wants to just pull the engine, sell it to someone looking for a genuine vintage L71, and put something a little more modern (pump gas friendly) in it.

Just add some octane booster at the correct amount to gallons of fuel.
Don't let it hammer itself to death, from too low of octane fuel.....JMHO & .02 ....

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