Reply
 
Thread Tools Search this Thread
 
Old 25 March 2021, 09:18   #1
Member
 
Country: UK - England
Town: Surrey/Cornwall
Make: Gemini GRX 420
Length: 4m +
Engine: Tohatsu D2 50Hp
Join Date: Aug 2011
Posts: 105
Anyone own a Gemini GRX 420

Just wondering if anyone on here owns a Gemini GRX 420?

I picked a used one up a month or so back. Be interested to speak to any owners, as I know they are a bit niche.
__________________
ThundercatRob is offline   Reply With Quote
Old 25 March 2021, 12:50   #2
Member
 
Country: UK - England
Town: Surrey/Cornwall
Make: Gemini GRX 420
Length: 4m +
Engine: Tohatsu D2 50Hp
Join Date: Aug 2011
Posts: 105
__________________
ThundercatRob is offline   Reply With Quote
Old 25 March 2021, 13:23   #3
Member
 
RickW's Avatar
 
Country: UK - England
Town: Cornwall
Boat name: Matchless
Make: Ribcraft 6.8m
Length: 6m +
Engine: Mercury 3.4l 225 V6
MMSI: 232028056
Join Date: Apr 2017
Posts: 286
RIBase
Would love to hear your thoughts was seriously tempted wit the idea of the GRX or Surfcat for beach launched fun. As you say not many around
__________________
RickW is offline   Reply With Quote
Old 25 March 2021, 14:00   #4
Member
 
Country: UK - Scotland
Make: Destroyer 5.5/Ring18
Length: 3m +
Engine: Yam 90HP/Yam200HP
Join Date: Jul 2009
Posts: 958
Click image for larger version

Name:	IMG_7082.jpg
Views:	267
Size:	66.3 KB
ID:	136690

I have a Surfcat [emoji41]
__________________
69cmw is offline   Reply With Quote
Old 25 March 2021, 17:03   #5
Member
 
Country: UK - England
Town: Surrey/Cornwall
Make: Gemini GRX 420
Length: 4m +
Engine: Tohatsu D2 50Hp
Join Date: Aug 2011
Posts: 105
Quote:
Originally Posted by RickW View Post
Would love to hear your thoughts was seriously tempted wit the idea of the GRX or Surfcat for beach launched fun. As you say not many around
Thanks, i will let you know once i get a chance to use it. Its currently stored in Lincolnshire, and I'm based in Surrey which is annoying. I will hopefully bring it back soon. Needs a bit of tidying up as well. Will give the engine a good service, and replace a few bits.

I've previously owned a Ceasar Thundercar. I'm hoping its going to be 90% a Thundercat, but the practicality of a normal SIB. Certainly the inside deck space seems much larger.

I was put off by a normal SIB due to their sea capabilities. The Thundercats were amazing even in terrible weather, I never felt worried even in big surf or large swell.

Its got the good old Tohatsu 50hp 2S, so should go alright.
__________________
ThundercatRob is offline   Reply With Quote
Old 25 March 2021, 17:05   #6
Member
 
Country: UK - England
Town: Surrey/Cornwall
Make: Gemini GRX 420
Length: 4m +
Engine: Tohatsu D2 50Hp
Join Date: Aug 2011
Posts: 105
Quote:
Originally Posted by 69cmw View Post
Attachment 136690

I have a Surfcat [emoji41]
Looks

Who makes that? Is it a Ceasar? What's your thoughts on them?
__________________
ThundercatRob is offline   Reply With Quote
Old 25 March 2021, 22:13   #7
Member
 
Roflhat's Avatar
 
Country: UK - Scotland
Town: Isle of Lewis
Boat name: Macleod Special
Make: Ceasar Thundercat
Length: 4m +
Engine: Yamaha 70ces
Join Date: Jul 2010
Posts: 1,189
RIBase
Surfcat is pretty close to the ideal all rounder in my opinion. Almost as fun and fast as a thundercat but with 5x the versatility. When I retire from thundercats I’ll get a surfcat again.
Yeh Ceasar make the surfcat
__________________
Roflhat is offline   Reply With Quote
Old 25 March 2021, 23:25   #8
Member
 
RickW's Avatar
 
Country: UK - England
Town: Cornwall
Boat name: Matchless
Make: Ribcraft 6.8m
Length: 6m +
Engine: Mercury 3.4l 225 V6
MMSI: 232028056
Join Date: Apr 2017
Posts: 286
RIBase
Well Bob hopefully see you on the water - I do think if rib is not the answer then zapcat / surfcat / GRX is a very interesting choice

I would have gone for one but ended up with a Ribcraft 6.8m funny how things change !
__________________
RickW is offline   Reply With Quote
Old 26 March 2021, 10:15   #9
Member
 
Country: UK - England
Town: Retford
Boat name: Spy-sea-one
Make: Excel 435
Length: 4m +
Engine: Suzuki Outboard/25/4
Join Date: Oct 2011
Posts: 7,441
RIBase
Quote:
Originally Posted by 69cmw View Post
Attachment 136690

I have a Surfcat [emoji41]



__________________
jeffstevens763@g is offline   Reply With Quote
Old 26 March 2021, 20:44   #10
Member
 
RickW's Avatar
 
Country: UK - England
Town: Cornwall
Boat name: Matchless
Make: Ribcraft 6.8m
Length: 6m +
Engine: Mercury 3.4l 225 V6
MMSI: 232028056
Join Date: Apr 2017
Posts: 286
RIBase
Cool vid ! Are surfcat/grx420 less slammy that the typical sib (compared to ribs)
__________________
RickW is offline   Reply With Quote
Old 28 March 2021, 10:18   #11
Member
 
Roflhat's Avatar
 
Country: UK - Scotland
Town: Isle of Lewis
Boat name: Macleod Special
Make: Ceasar Thundercat
Length: 4m +
Engine: Yamaha 70ces
Join Date: Jul 2010
Posts: 1,189
RIBase
They almost never slam, very occasionally have a hard landing when you jump a wake and land on the following peak. But in normal use they never slam, got a cushion of air between the hulls which dampens the ride
__________________
Roflhat is offline   Reply With Quote
Old 30 March 2021, 20:35   #12
Member
 
Country: UK - England
Town: Surrey/Cornwall
Make: Gemini GRX 420
Length: 4m +
Engine: Tohatsu D2 50Hp
Join Date: Aug 2011
Posts: 105
Thanks for all the information. Certainly looking forward to getting out in it.

Not sure if my arm will last long hanging onto a 50hp. My old Thundercat had a steering damper. This hasn’t, so it will be interesting to see how much I have to fight if it.
__________________
ThundercatRob is offline   Reply With Quote
Old 31 March 2021, 07:52   #13
Member
 
Roflhat's Avatar
 
Country: UK - Scotland
Town: Isle of Lewis
Boat name: Macleod Special
Make: Ceasar Thundercat
Length: 4m +
Engine: Yamaha 70ces
Join Date: Jul 2010
Posts: 1,189
RIBase
There's a tiller extension + damper set up for sale on ebay just now
__________________
Roflhat is offline   Reply With Quote
Old 31 March 2021, 09:02   #14
Member
 
Country: UK - England
Town: Surrey/Cornwall
Make: Gemini GRX 420
Length: 4m +
Engine: Tohatsu D2 50Hp
Join Date: Aug 2011
Posts: 105
Yes, I did see that. That's the exact same setup i had on my Thundercat. Have you ever driven one without a damper?

I'm keen to try it without first to see what its like. The previous owner said he kept it standard so there was more deck space inside the boat.
__________________
ThundercatRob is offline   Reply With Quote
Old 15 May 2021, 21:16   #15
Member
 
Country: UK - England
Town: Surrey/Cornwall
Make: Gemini GRX 420
Length: 4m +
Engine: Tohatsu D2 50Hp
Join Date: Aug 2011
Posts: 105
Managed to get my trailer engine support made and fitted. It’s slightly to low at the moment, so need to adjust the cross member it’s bolted to, but should work as intended.

__________________
ThundercatRob is offline   Reply With Quote
Old 17 May 2021, 21:00   #16
Member
 
Country: UK - England
Town: Surrey/Cornwall
Make: Gemini GRX 420
Length: 4m +
Engine: Tohatsu D2 50Hp
Join Date: Aug 2011
Posts: 105
Managed to do a bit of work on the engine tonight.

Started off with the impeller. I dropped the leg off and opened up the housing. Impeller was ok, but I noticed that the housing was cracked, so I’m going to need to order a new one. So I put all the old bits back in.

I’m not sure if this is common, but I had a cracked housing on my Thundercat Tohatsu 50.











I did manage to empty the gearbox oil out and it looked clean which is positive.

Any marine grease recommendations?
__________________
ThundercatRob is offline   Reply With Quote
Old 20 June 2021, 14:41   #17
Member
 
Country: UK - England
Town: Surrey/Cornwall
Make: Gemini GRX 420
Length: 4m +
Engine: Tohatsu D2 50Hp
Join Date: Aug 2011
Posts: 105
Finally got the boat out for its first outing.

Engine wasn’t 100%, so I’ve currently got the carbs off for a clean and ordered some new coil packs. I will also get a few new bits, like fuel pump kit etc. Hopefully this should sort it out.

__________________
ThundercatRob is offline   Reply With Quote
Old 09 July 2021, 20:50   #18
Member
 
Country: UK - England
Town: Surrey/Cornwall
Make: Gemini GRX 420
Length: 4m +
Engine: Tohatsu D2 50Hp
Join Date: Aug 2011
Posts: 105
Well had the boat out this week. Launched down at Loe Beach, in Cornwall.

I’ve recently replaced all the coil packs with upgraded Naraku racing ones, cleaned all the carbs and rebuilt the fuel pump. The engine is running much better now.

Thanks Roflhat for all the help and advice!

Top speed was a bit slower than I had hoped. However I’ve noticed the throttle isn’t opening fully, so I need to adjust that. I might also take off the prop guard to see how much that takes off the top speed!
__________________
ThundercatRob is offline   Reply With Quote
Old 15 July 2021, 19:37   #19
Member
 
Country: UK - England
Town: Surrey/Cornwall
Make: Gemini GRX 420
Length: 4m +
Engine: Tohatsu D2 50Hp
Join Date: Aug 2011
Posts: 105
Throttle now adjusted - hopefully correctly.

Flaps are now fully horizontal at WOT on the tiller.

Heading down to Hayling Island tomorrow to launch at the Ferry Boat.

I think I might also unbolt the prop guard as well and see what difference it makes.

Not sure where we will head yet, probably just head out of the harbour and see where takes our fancy.
__________________
ThundercatRob is offline   Reply With Quote
Old 16 July 2021, 07:06   #20
Member
 
Roflhat's Avatar
 
Country: UK - Scotland
Town: Isle of Lewis
Boat name: Macleod Special
Make: Ceasar Thundercat
Length: 4m +
Engine: Yamaha 70ces
Join Date: Jul 2010
Posts: 1,189
RIBase
Take that prop guard off, will never go back on
__________________
Roflhat is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




All times are GMT. The time now is 06:13.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.