My thundercat

[Roflhat]

3 scrap cranks later... I've sent the original crank away to have all the main bearings replaced, dynamically balanced, conrods and pistons weight matched and then welded.


Decided to use one of the other blocks to try the 90 carbs on. Had to countersink the top screws on the bottom 2 carbs. Took the 165 main jets out of the 70 carbs and put them in the 90 carbs.


The throttle and choke linkages from the 70 carbs all seem to work on the 90 ones.

The throttle cam isn't perfect, rubs on the metal part of the carbs a wee bit, going to wait until it's back together and see how it goes.
Think I'm going to have to cut a hole in the tray for the bigger bowls on the carbs.

Also put the CCM reeds on this one, removed the stops as well.

[spartacus]

Once you get the engine back together get the Enduro cowl painted and some new decals on it. Looks sorry for itself.

[Roflhat]

Originally Posted by spartacus

Once you get the engine back together get the Enduro cowl painted and some new decals on it. Looks sorry for itself.

Yeh it's not looking too good just now! The old decals are pretty well stuck on there, I was looking at maybe vinyl wrapping it instead of paint

[spartacus]

Originally Posted by Roflhat

Yeh it's not looking too good just now! The old decals are pretty well stuck on there, I was looking at maybe vinyl wrapping it instead of paint

Hairdryer and patience. Job done. You can remove adhesive residue with a little petrol or rubbing alcohol.

Not sure how vinyl wrap would work on a cowl given the edges and angles.

[Roflhat]

Originally Posted by spartacus

Hairdryer and patience. Job done. You can remove adhesive residue with a little petrol or rubbing alcohol.

Not sure how vinyl wrap would work on a cowl given the edges and angles.

Was at it for an hour with a heat gun and nail varnish remover (meant to be good for this sort of thing), removed about a square inch!

[spartacus]

Originally Posted by Roflhat

Was at it for an hour with a heat gun and nail varnish remover (meant to be good for this sort of thing), removed about a square inch!

Wonder if the whole thing has been given a coat of lacquer in a previous life? Rotary sander would be my weapon of choice.

[Roflhat]

Originally Posted by spartacus

Wonder if the whole thing has been given a coat of lacquer in a previous life? Rotary sander would be my weapon of choice.

possibly, I'll give that a go and see how I get on.

Latest prop, got this from America, Yamaha 15G Semi-Cleaver. Should make a good all round/surf prop.
I wouldn't mind a 16G of the same prop, I think the 70 will spin that no bother

[lukewhiting]

When I resprayed my tohastu cowling I just used an electric sander.

Left the decals on and sanded them off.

You have to sacrifice a sanding pad for the decals but it was pretty easy!

[Roflhat]

Another addition to the collection, 10x19 overhub Cleaver

Here's the collection minus 2x Solas 15p props

[two stroke mick]

Not much give in the over hub prop if you hit a rock

[Roflhat]

Originally Posted by two stroke mick

Not much give in the over hub prop if you hit a rock

unfortunately not! the OMC cleavers are solid hub too

[Roflhat]

home for a few days, started putting the engine back together.
Got the crank back from balancing + new bearings + welding


Got everything put back together, 90 carbs are on - had to cut the tray to accomodate the deeper bowls.


Going to get the floorboards back in tomorrow and try get the engine going

[lukewhiting]

Looking good!

Will be picking your brains for parts when I get my engine

[Roflhat]

Originally Posted by lukewhiting

Looking good!

Will be picking your brains for parts when I get my engine

Cheers, you getting another thundercat?

[lukewhiting]

Originally Posted by Roflhat

Cheers, you getting another thundercat?

Yeah I'm slowing building this boat. Carbon nose cone and floors. Got the hull and trailer. Just kitting it out then buying an engine last

[Roflhat]

Nice, shame the nose cone is painted, would look mint in carbon.
What engine you going for?

[Roflhat]

Designed some stacks, I've ordered a set and depending how they go I may start selling sets.






They are quite short as there isn't too much room with the 90hp carbs.

I've also designed stacks for tohatsu 50's

[lukewhiting]

Originally Posted by Roflhat

Nice, shame the nose cone is painted, would look mint in carbon.

What engine you going for?

Yeah, you can see the weave through the paint. Am looking at getting it wrapped or dipped in a carbon effect.

Going for a 50hp tohatsu and just planning on doing some mild tuning, may race it so will keep it race legal.

[Roflhat]

Went out for a spin today after adjusting the mixture to help with low down. Ran a lot better, topped out at 54.7 knots with th 21g cleaver. Took the main jets out and replaced them with the 160's. Using small drill bits for reference:
165 = 1.65mm
160 = 1.85mm

So I'd guess the 160's have maybe been drilled out at some point, they were in the 90 carbs which I got from a racing guy. Still need to try it again with these jets. Also need to smooth the intake on the reed block, there is a slight step between the carbs and the reed block.

[Roflhat]

ran terribly with the 1.85mm jets... Idle has dropped about 200rpm, acceleration seems much better but doesn't go. Also found one of the carb gaskets was torn, I think it was probably while I was removing the carb as the engine was running fine. I replaced it when I swapped the jets over
I guess I need around 1.7mm or 1.75mm jets?