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Re: Lake Tahoe Cobalts
Posted: Sun May 05, 2024 12:12 am
by Bull0080
Lifelongbtr wrote: Fri May 03, 2024 3:57 pm
Nice looking boat! I am talking with a few home owners up in the keys and hope to land a slip for at least part of the summer, I'll say hi if I see big red out there.
Thank you! Looking forward to it. I have a friend (our old slip) looking to fill since we upgraded. I believe it will fit 22ā or 25ā max. Cheers
Re: Lake Tahoe Cobalts
Posted: Mon May 20, 2024 7:00 pm
by Lifelongbtr
Bull0080 wrote: Sun May 05, 2024 12:12 am
Lifelongbtr wrote: Fri May 03, 2024 3:57 pm
Nice looking boat! I am talking with a few home owners up in the keys and hope to land a slip for at least part of the summer, I'll say hi if I see big red out there.
Thank you! Looking forward to it. I have a friend (our old slip) looking to fill since we upgraded. I believe it will fit 22ā or 25ā max. Cheers
Mine is an R7 so sounds like it wouldn't fit, but I am meeting next week to hopefully secure one not being used!
Re: Lake Tahoe Cobalts
Posted: Sat Jul 27, 2024 7:15 pm
by cvx16
Hey All. I'm a San Diego boater but just arrived in Tahoe with my 25SC and Yamaha F300 outboard. It's got some altitude sickness at the moment. Can't get it over 3000 RPMs. I've got an 18p prop on it, so I'm sure I need to pitch it down a little, but there seems to be some automatic adjustments it's not making yet. Wondering if anyone has any tips on how to help coach the motor into knowing the altitude and to adjust?
When I first launched yesterday, it was me and my 2 teenagers with me. We ran it at around 3k RPM and after a few mins it decided to get up and go and seemed normal and had much more power. Then today, we had more people in the boat. 8 total, including 2 kids. So quite a bit more load. Could never get it over 3k RPMs at all.
Just put 91 octane from Shell in the boat too. Also just had the boat serviced a couple months ago, so fuel filter is new.
Any thoughts or tips would be appreciated. I'm going to have some pissed off teenagers soon if we can't get wakeboarding or tubing this week.
Re: Lake Tahoe Cobalts
Posted: Sat Jul 27, 2024 7:58 pm
by bruceb58
What kind of RPM do you get at sea level? You pretty much always have to reduce prop pitch when you go to altitude. My boat is a sterndrive but has has a 3" pitch drop from 24" to 21" for Tahoe
Re: Lake Tahoe Cobalts
Posted: Sat Jul 27, 2024 10:58 pm
by Lifelongbtr
cvx16 wrote: Sat Jul 27, 2024 7:15 pm
Hey All. I'm a San Diego boater but just arrived in Tahoe with my 25SC and Yamaha F300 outboard. It's got some altitude sickness at the moment. Can't get it over 3000 RPMs. I've got an 18p prop on it, so I'm sure I need to pitch it down a little, but there seems to be some automatic adjustments it's not making yet. Wondering if anyone has any tips on how to help coach the motor into knowing the altitude and to adjust?
When I first launched yesterday, it was me and my 2 teenagers with me. We ran it at around 3k RPM and after a few mins it decided to get up and go and seemed normal and had much more power. Then today, we had more people in the boat. 8 total, including 2 kids. So quite a bit more load. Could never get it over 3k RPMs at all.
Just put 91 octane from Shell in the boat too. Also just had the boat serviced a couple months ago, so fuel filter is new.
Any thoughts or tips would be appreciated. I'm going to have some pissed off teenagers soon if we can't get wakeboarding or tubing this week.
Iāve never owned an outboard so canāt speak from experience but Iād say it may be something other than just pitch. Iāve had three boats, carbureted, MPI, and fuel injection that Iāve taken from sea level to Tahoe and havenāt had that bad of results. The carbureted boat being the worst. My current stern drive doesnāt perform as well up there but 15 ppl it still gets on plane pretty quick.
Is your boat on plane and still stuck at 3k? Do you have an auto trim setting on it? Assuming youāre trimmed all the way down and still wonāt get about 3k?
Re: Lake Tahoe Cobalts
Posted: Sun Jul 28, 2024 3:01 pm
by cvx16
Sea level RPMs are usually 5700'ish. Although we don't boat where we can really open it up often.
Just took the boat out this morning with just 1 other person. We could get on plane eventually. It reved up slowly and then finally caught and we could got WOT at 5500-5600. Tried doing it repeatedly from idle and each time it would take 20-30 seconds for it to finally open up.
Hoping we can get a lower pitch prop tomorrow when shops are open, but I'm wondering if that is the only issue or if we're still going to have issues. I'm kind of assuming the latter.....
Re: Lake Tahoe Cobalts
Posted: Sat Aug 03, 2024 12:39 pm
by cvx16
Short update on the previous noted issues with my 300 Yamaha in Tahoe's elevation. John Shearer at Lake Tahoe Boat Company hooked me up with a new prop on Monday, even though his shop is not open Mondays. Shout out to John and a recommendation for his shop!
I replaced my 18p 15 1/4" stainless with a 16p 16" painted steel. It helped a little and we were at least able to get on plane (eventually) with all people in the boat. But there is definitely still something to be done with this. We had to do pretty extreme weight shifting in the boat (everyone in the front) just to get on plane and there would be a point where the motor would "kick in" and rev up to full RPM and speed. Then we could shift weight around no problem. If the motor would start with it's available power from the start, I don't think there would be any issues at all. So we'll just keep trying to sort that out. But we're now back in San Diego, so not sure when the next opportunity will be, but I'll update when I know more.
Re: Lake Tahoe Cobalts
Posted: Mon Aug 05, 2024 7:44 pm
by cvx16
After a few more conversations, it seems the conclusion is the prop resizing from 18" to 16" is probably about all I can do and our 25SC is pretty much underpowered with the 300hp outboard at the elevation of Lake Tahoe. It's rated for a max of 350hp and I wish it had it, but it doesn't.
Does anyone else boating in Tahoe have a 25SC with a 300hp or 350hp? What's your experience?
Re: Lake Tahoe Cobalts
Posted: Mon Aug 05, 2024 10:31 pm
by cvx16
At least I can share a picture for the tangent conversation. Beautiful lake and we enjoyed the week either way.
Re: Lake Tahoe Cobalts
Posted: Mon Aug 05, 2024 10:47 pm
by Lifelongbtr
cvx16 wrote: Mon Aug 05, 2024 10:31 pm
At least I can share a picture for the tangent conversation. Beautiful lake and we enjoyed the week either way.
Great looking boat! And yes the lake is great, views are always awesome.
We had an outboard growing up, 2 stroke, and other than that no experience. That said Iāve seen 350hp R7ās for sale around Tahoe, and maybe thatās why they are selling them. My 430 R7 surprises me each time I take it out, sea level prop and I wouldnāt think for a second buying one for elevation, it gets the job done loaded with ease so itās hard to imagine yours struggling as thereās also less weight.
With my little knowledge of OBās not sure if there is also a gear ratio that comes into play. Many boats around Tahoe and Coeur dāAlene for example order stern drives with a different out drive ratio too. Before that I heard, and not sure, back in the day the fuel jets were ordered different too. I donāt know the type of fuel injection used on the newer OBās?
As you probably saw, not a ton of OBās on Tahoe except big multi engine boats or pontoons. There was an R8 with an OB parked next to me last year, Iāll certainly ask around and let you know if I hear anything useful.
Re: Lake Tahoe Cobalts
Posted: Mon Aug 05, 2024 10:50 pm
by Lifelongbtr
cvx16 wrote: Mon Aug 05, 2024 10:31 pm
At least I can share a picture for the tangent conversation. Beautiful lake and we enjoyed the week either way.
One other thought, catch the local dealer, west coast boat center on a slower day and ask, theyād know if thereās been problems with that setup there.
Re: Lake Tahoe Cobalts
Posted: Mon Aug 05, 2024 11:34 pm
by cvx16
Thanks guys. I've had some similar thoughts on gear ratios, but I don't know enough to know if these newer 4-stroke OBs should be set up differently for sea level vs elevation. But the way the motor acts, its like driving a manual transmission car and starting off in 3rd gear every time. You can do it but until you're on plane, it's not really gonna take off. Not a perfect analogy, but seems close.
I called West Coast Boat Center today. Not sure who I talked to, but he said they don't know much about outboards there and to call Walker Marine. I called Walker Marine (had left them a message last week, but never heard back) and they pretty much said the same thing. They're a Mercruiser and Volvo sterndrive shop and they refer OBs to Lake Tahoe Boat Company, which is where I got the 16" prop last week. Although, the guy at Walker Marine is the one that said it basically sounds like the boat is underpowered for elevation, especially when loaded up with gear, fuel and people. He also gave me one other tip which I hadn't heard before. He talked about "walking" the boat up on plane. Basically if the boat is struggling to get on plane, you can try to walk it up on plane, by turning the wheel back and forth trying to get the edges of the hull to "walk" up and get on plane. Very interesting and never heard of anyone doing that before. I'll have to try it next time.
Re: Lake Tahoe Cobalts
Posted: Mon Aug 05, 2024 11:37 pm
by bruceb58
Lifelongbtr wrote: Mon Aug 05, 2024 10:47 pm
Before that I heard, and not sure, back in the day the
fuel jets were ordered different too. I donāt know the type of fuel injection used on the newer OBās?
Yes...for carburetors.
Re: Lake Tahoe Cobalts
Posted: Mon Aug 05, 2024 11:40 pm
by bruceb58
West Coast Boats in Rocklin usually refers people to the propeller shop that I go to in Ventura CA.
This is their website. It's also where I buy my propellers since they have the best price.
https://www.valleypropellerservice.com/
Re: Lake Tahoe Cobalts
Posted: Mon Aug 05, 2024 11:50 pm
by Lifelongbtr
cvx16 wrote: Mon Aug 05, 2024 11:34 pm
Thanks guys. I've had some similar thoughts on gear ratios, but I don't know enough to know if these newer 4-stroke OBs should be set up differently for sea level vs elevation. But the way the motor acts, its like driving a manual transmission car and starting off in 3rd gear every time. You can do it but until you're on plane, it's not really gonna take off. Not a perfect analogy, but seems close.
I called West Coast Boat Center today. Not sure who I talked to, but he said they don't know much about outboards there and to call Walker Marine. I called Walker Marine (had left them a message last week, but never heard back) and they pretty much said the same thing. They're a Mercruiser and Volvo sterndrive shop and they refer OBs to Lake Tahoe Boat Company, which is where I got the 16" prop last week. Although, the guy at Walker Marine is the one that said it basically sounds like the boat is underpowered for elevation, especially when loaded up with gear, fuel and people. He also gave me one other tip which I hadn't heard before. He talked about "walking" the boat up on plane. Basically if the boat is struggling to get on plane, you can try to walk it up on plane, by turning the wheel back and forth trying to get the edges of the hull to "walk" up and get on plane. Very interesting and never heard of anyone doing that before. I'll have to try it next time.
Interesting. Iāve been boating my whole life and have driven dozens of different boat all over. My R7 is the quickest āon planeā boat Iāve ever owned, and I donāt think itās all power related. I do know what heās talking about, as Iāve been in the situation myself, youāre right there, and make a slight turn (and usually back) and the boat planes. That said it was just a quicker way to get there, those loaded boats I was driving wouldāve gotten there with time I think.
Many times weād shift people from back to front getting on plane quicker, any trick in the book. Usually driving my dads boat.
There is also the water conditions. Tahoe is usually not flat, and each wave delays the outcome.
Sounds like you had a good time though, and thatās all that matters in the end.
