Installing tachometer on rope started tiller engine?

Patrik · 05 August 2011, 09:34

Hey

Got a crazy idea that it would be fun to install a tachometer to see how the engine is performing. But it's a pulley started outboard with tiller!

Can't find any examples of this on the net. Is it even possible?

Regards,
Patrik

Poly · 05 August 2011, 09:39

It may be possible relatively easily using traditional gauges depending on what wiring is hiding inside the cowel. However by far the simplest way without a 12v battery, is the tinytach approach... a search should find various posts on this.

jyasaki · 05 August 2011, 09:55

Second Tinytach.

Info here: Tiny-Tach: Gasoline Tachometers

jky

Patrik · 05 August 2011, 14:22

Sounds like a smart device! Where should I put the display? Thinking of putting it just on top of the engine.. Is it just one wire between the display and the part wrapped around the plug chord?

jyasaki · 06 August 2011, 04:40

Sit where you normally pilot the boat from, and figure a spot you can see it without doing any kind of contortionism. I'd think the side of the motor towards the front would work, but would involve mounting holes in the cover. (Though I suppose you could use double-sided foam ape and plan on replacing it every now and then.)

If it were me, I'd zip tie it somewhere inside the cowl, and simply remove the cover when I wanted to get rpm readings.

jky

Sorry; the connections are: a ground wire (tied to the motor block or other groundpoint), and a wire that wraps around a spark plug wire. That's it, as far as I know.

chris123 · 06 August 2011, 07:25

I have a TinyTach on my outboard, works really well.

Mine is cable tied in front of the cowl.

You need to get the right version for the sparking pattern for your outboard.

Cheers

Chris

Fenlander · 06 August 2011, 09:19

That looks good Chris... probably the best place for one. I'm just a bit put off with the fact you can't replace the battery and have to regard a £60 device as disposable. I wonder if its life would be related to how long the engine runs as well as the time the unit is in standby?

I've nearly bought one a couple of times... this 100% seller looks OK...

Standard Tiny-Tach

I have a laser rev counter for tuning at home in the tank and on the water for a one-off check with a helper. Will use it on this year's hols to check out my prop sizing. Obviously you have to do a few runs with the cowl off so it's not as user-freindly as the TinyTach.

Could be useful for some folks though and only a tenner.

Digital Laser Photo Tachometer Non Contact RPM Tach | eBay

chris123 · 06 August 2011, 10:33

I'm not sure how much the battery life is affected by run time - the unit is permanently on (displaying hours run) even if the outboard is not running.

I would get a price direct:

Tiny-Tach: Contact page for ITCO

Richard Dunn is a really helpful bloke - when my TinyTach cable broke after a couple of years, he sent me a new cable.

SIB (lack of) performance seems to be a popular topic - when you look at the costs of outboards / props / mechanic's time, £60 strikes me a s a good investment.

Cheers

Chris

ferryden · 07 August 2011, 10:56

I've ordered the hand held laser tach Chris... question of cost but I agree it may well prove to be an investement that's worthwhile (and clears up a lot of my frustration!)
Thanks mate..

Guys, I bought a new tank and fuel line, which seems to feed fuel without any problem (no cutting out or lumpy ride). At the time there were larger diameter fuel pipes... what difference could the flow rate with a larger diameter fuel pipe make to performance one way or the other? (I take it the engine will run at same rate as it's via carb etc?)

Poly · 07 August 2011, 11:06

Quote:

Originally Posted by ferryden

At the time there were larger diameter fuel pipes... what difference could the flow rate with a larger diameter fuel pipe make to performance one way or the other? (I take it the engine will run at same rate as it's via carb etc?)

It won't make any difference on a 15HP engine. Some larger engines can't suck enough fuel through the smaller pipes and therefore have problems.

Patrik · 07 August 2011, 15:55

Ah nice install there Chris, that was just like I imagined, except I thought I'd place it on the cover! But that's more clever so the cover wont be attached to the engine with a wire. Really cheap tach there! Cheapest in sweden is £40..

Patrik · 07 August 2011, 20:23

Quote:

Originally Posted by Fenlander

I have a laser rev counter for tuning at home in the tank and on the water for a one-off check with a helper. Will use it on this year's hols to check out my prop sizing. Obviously you have to do a few runs with the cowl off so it's not as user-freindly as the TinyTach.

Could be useful for some folks though and only a tenner.

Digital Laser Photo Tachometer Non Contact RPM Tach | eBay

If I use one of these, how do I measure? I mean I have to measure with the propeller in the water, otherwise I suppose it's meaningless...

Fenlander · 07 August 2011, 21:01

The laser tach will measure anything that turns or spins. Many things will give a good reading by themselves but they do supply small reflective strips (sticky back) to put on any surface that doesn't give a good return on the laser.

On an outboard you just leave the cowl off and take the reading from the spinning flywheel. It will do it from a metre away so quite safe. You do really need an assistant when out on the water.

Patrik · 07 August 2011, 21:08

Ah so it is that simple... Yeah that's no problem, I can have someone sit beside me. So the flywheel goes in the same speed as the prop? There's no gearing going on?

Fenlander · 07 August 2011, 21:13

There is gearing at the lower unit... usually around 2:1 for a 10-20hp. But it's not prop speed you want to know... it's the engine flywheel speed for the engine RPM.

Patrik · 07 August 2011, 21:27

Oh okay, really good to know! Wish I would have taken care of this business earlier, now I have already taken a chance and bought a new prop with the world's longest delivery time. Perhaps you have some ideas of firms in the UK that sells props cheaply? I'd like aftermarket props, anything to get them as cheap as possible. Solas or something was the name of the one I ordered. Extremely expensive in Sweden, just as everything else...

Fenlander · 07 August 2011, 23:05

Not sure what you call cheap but these are the folks many of us deal with...

Steel Developments - New Propellers & Propeller Repairs - UK Wide Delivery _ New propellers available from stock & prop repairs in very quick lead times

I've a spare new prop on the way from them at the moment.

Patrik · 07 August 2011, 23:30

I'm sending them a mail asking for international delivery.. I see that you have got 20% VAT, has it been increased lately or has it always been that much? (we have got 25% in sweden since 30 years or something)

Fenlander · 07 August 2011, 23:32

Yep VAT was 15% a couple of years ago, then 17.5% and now 20%.