Search found 23 matches

by JhlFin
Fri Aug 14, 2020 9:48 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

I went for a ride yesterday, now with fully working gps. 40mph/3200rpm so slip would be 12% :D Im really happy! Im thinking of upgradin engine next winter so maybe i keep prop as is for now.

I got to say boating is fun!
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by JhlFin
Tue Aug 04, 2020 7:04 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

Well, it took longer than it should, but finally got to test drive. There is something wrong with carb, wont idle. Carb is clean and every orfice is open, i think i will swap better/bigger carb. Propeller is now 10x15 with cup and 5 degrees rake, much better! I ran out of power 😅 engine only revved ...
by JhlFin
Mon Apr 06, 2020 9:06 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

Yes, engine over revs. 10-20% slip sounds reasonable, my prop slips way too much right now. I would be happy with 30-40% slip. I cant wait to get prop back from shop and testdrive.
by JhlFin
Sun Apr 05, 2020 12:54 pm
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

Kens, how much prop slip normally those boats have? This is whole new world to me, it is very challengin but fun. Here in Finland usually inboard boats are displacement hull types and it is hard to find information because of it. This forum is totally life saver, nice people and lot of photos and in...
by JhlFin
Fri Apr 03, 2020 8:58 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

It has 1:1 Gear ratio, direct drive. Marine engine based on this is rated at 5500rpm max, i have rev limiter at 6500(not stock engine). I think max cruise rpm will be 4000 and will run short periods of time at 6000rpm. Im not worried about running high rpm, these are sturdy little engines and it won...
by JhlFin
Thu Apr 02, 2020 9:29 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

Sorry, my english is not that good :oops: So propeller diameter will be cut from 11" to 10". Pitch will remain 15" and cup is added. If it is needed, i will try more pitch. Prop guy said that with high rpm bigger propeller will start to cavitate from high tip speed. Smaller prop should have cleaner ...
by JhlFin
Wed Apr 01, 2020 10:31 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

Little update, i found propshop that was willing to modify my propeller. We talked a bit and we decided to cut prop to 10" as blade tip speed gets too high and causes cavitation, also prop will be cupped. They will also measure rake of propeller and change it to 5 degrees aft rake if it is less. May...
by JhlFin
Wed Apr 01, 2020 10:24 am
Forum: Boat Power
Topic: CVT scooter motor as inboard?
Replies: 7
Views: 2845

Re: CVT scooter motor as inboard?

It might not be that bad idea, probably needs lot of testing and tuning. I'm no expert at cvt:s but in know those can be modded to work on diffrent applications with weights and springs. You could also use chain drive from cvt to propshaft and do gearing there as needed. If you have tools and materi...
by JhlFin
Wed Nov 27, 2019 9:12 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

Im thinking that my prop is not made for high speed/rpm, blades are thick and not even finished properly from what i can tell. i cant find any other suitable props in Finland. I would be very happy if someone could guide me to find and choose right steel prop. I think someone used 10x15 2 blade stee...
by JhlFin
Fri Nov 22, 2019 8:11 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

Last testdrive for this season with new strut. New tachometer acted pretty much same as old, need to check wiring. Dont have accurate reading, but max speed was pretty much the same. So strut was not the issue. I feel like front of boat is too heavy or trim tabs were at wrong position. Lots of work ...
by JhlFin
Mon Nov 18, 2019 9:48 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

Finally got new strut made, took long enough. Had litte problems when welded strut, warpped strut housing. First bearing was destryed while installing. Little bit of work and i tought that now it would be good, but not... Second bearin installed, well guess what? too tight :D Well i sanded it a bit ...
by JhlFin
Sun Oct 13, 2019 11:30 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

I cant drive wide open with either prop, engine will over rev(no limiter) With 11x15 6000rpm speed was 35mph. 10x12 at 6000rpm speed was 28mph. With smaller prop it went worse at every rpm, felt it right away. I know that clutch may slip, but i if thats the case, i think with smaller prop it should ...
by JhlFin
Sun Oct 13, 2019 7:34 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

Tried other prop repitched, so now 10x12. Quite funny really, at 6000rpm prop slip was again 59% :lol:

So yeah, i guess that strut is just that bad. I ordered new rubber bearing, smallest i could find. Little bit machining and welding and ill guess try again :D
by JhlFin
Wed Oct 02, 2019 10:15 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

Im sourcing materials for new strut, have not found yet. Well i could make it from steel, i have materials for that, i guess rust wont be an issue with good paint and boat always on trailer. Water around me is brackish i think. I live in an island, in smallest town in Finland :D Just machined taper ...
by JhlFin
Fri Sep 27, 2019 10:47 am
Forum: Boat Power
Topic: Tiny might propeller slip
Replies: 34
Views: 16963

Re: Tiny might propeller slip

I have 10x10 prop with wrong taper. I guess ill try that after some machining. And Thanks for replies! It helps a lot, helps to think :D

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