4.1 rib 50hp tiller steer

[Locozodiac]

Originally Posted by ian parkes

Yes I can't wait to get it run in . The motor starts missing if i run slow for a while , I hope its just the plugs getting a bit oiled , a quick burst of wot cures it , but thats not always possible if its a bit lumpy so i can't go play for another 4 hrs
sods law on the gas tilt , nothing ever comes together simply with boats does it
Yes my motor came from extreme marine , the last one

Hola Ian

You finally made it, muchos congrats, cute small capt, nice rib & engine configuration, some issues:

1-Don't think that by going 25:1 to 50:1 oil after first 10 hours will improve full wot top end speed inmediately, will take a few more hours for the engine to settle it's piston/rings/cylinders, the only difference is that now you can wot at any lenght of time. Clean your spark plugs before changing to 50:1 oil mix, regap if neccesarry to 1.00 mm or (0.40") shim tight.

2-Most Tohatsu engines that have in use, or have installed, comes with the swivel bracket adjusted towards light load, this factory adjustment can tired your arm on long distances, choppy water fast rides, or lose boat control when full wotting under un experienced persons in command. Maybe should adjust your bracket load bolt slightly 5º CW to increase a bit the load, specially if your daughter will be at the comandd of the Toh 50 at faster speeds once break in engine period is over.

3-Tohatsu's works perfect trimed on the second hole from transom, or at a position that matches 90º, boat bottom & perpendicular engine leg configuration. Place gas tank & passengers towards bow to have better rib balance and plane faster. Welcome on board!

Happy Ribbing

[JSP]

Ian,
I see by the pictures posted that your towing with a VW transporter/Carvelle? What ebgine does it have and how do you find it for towing?
Cheers mate.

[Easyrider]

Originally Posted by ian parkes

Yes I can't wait to get it run in . The motor starts missing if i run slow for a while , I hope its just the plugs getting a bit oiled , a quick burst of wot cures it , but thats not always possible if its a bit lumpy so i can't go play for another 4 hrs
sods law on the gas tilt , nothing ever comes together simply with boats does it
Yes my motor came from extreme marine , the last one

When it runs lumpy-is it at idle speed?

[ian parkes]

Originally Posted by Easyrider

When it runs lumpy-is it at idle speed?

After about an hour of cruising especially if I have gone slow off the plane for a few minutes it then stats to miss when I cruise again between 4 and 5 k . A quick blast of WOT seems to cure it for a while . I have been cleaning the plugs after each trip .
I hope its just extra oil fouling the plugs . i have chacked the fuel filter and drained the carbs just incase but all was clean .

[ian parkes]

Originally Posted by JSP

Ian,
I see by the pictures posted that your towing with a VW transporter/Carvelle? What ebgine does it have and how do you find it for towing?
Cheers mate.

The VW transporter is a 130 5cyl 2.5 . they are rated to tow 2500 kg
It tows very well with lots of pulling power , one of the best towing vehicles i have owned , not that i have very much to tow now. probaly not the greatest thing on a slippery slipway unless you get the 4wd version

[JSP]

Oh well, I better really rag the backside out of mine then. I've only got the 1.9TD, plus it's a 9 seater plus it's the LWB. If it comes to a hill and I'm towing I'll have to start throwing bodies out to push

[Easyrider]

Originally Posted by ian parkes

After about an hour of cruising especially if I have gone slow off the plane for a few minutes it then stats to miss when I cruise again between 4 and 5 k . A quick blast of WOT seems to cure it for a while . I have been cleaning the plugs after each trip .
I hope its just extra oil fouling the plugs . i have chacked the fuel filter and drained the carbs just incase but all was clean .

I had a similar problem with mine-I found that the carb mixtures were very rich on the middle and bottom carb-ideally the mixture screws chould be 1 1/2 to 2 1/2 turns out- on mine, they were top-2 3/4 ,middle-3 1/2, bottom 4 !!!turns out. This actually caused me to loose the bottom plug because it totally flooded it after doing a couple of fast start/stops in a row. Ive got it running nicely now with the screws at top-2,middle2 1/4, bottom 2 1/2. If i went any leaner on the bottom one it wouldnt idle smoothly. Another thing i noticed on mine was that the wires to the flywheel were stopping it from getting full ign advance because they where trapped inside the black box-its an easy check to do, just open the throttle fully (with engine not running) and check that the slidy bit with the timing marks on it under the flywheel moves and stops against the casting near the carbs-if it doesnt hit it then the wires are probably restricting it.

[ian parkes]

Originally Posted by Easyrider

I had a similar problem with mine-I found that the carb mixtures were very rich on the middle and bottom carb-ideally the mixture screws chould be 1 1/2 to 2 1/2 turns out- on mine, they were top-2 3/4 ,middle-3 1/2, bottom 4 !!!turns out. This actually caused me to loose the bottom plug because it totally flooded it after doing a couple of fast start/stops in a row. Ive got it running nicely now with the screws at top-2,middle2 1/4, bottom 2 1/2. If i went any leaner on the bottom one it wouldnt idle smoothly. Another thing i noticed on mine was that the wires to the flywheel were stopping it from getting full ign advance because they where trapped inside the black box-its an easy check to do, just open the throttle fully (with engine not running) and check that the slidy bit with the timing marks on it under the flywheel moves and stops against the casting near the carbs-if it doesnt hit it then the wires are probably restricting it.

Thanks for that info , very good to know , especially the timing .
Any idea why your air screws needed setting different on each carb ? Haven't checked mine extreme marine said they set them up and run them etc before delivery so I trusted they had .

I had a strange issue today . We left the beach heavily loaded with five of us and a load of gear . I we had to launch in the surf so I warmed the motor up well while holding the boat head to waves then jumped in quick and went . The boats just lacked power and wouldn't rev past 4300 k for about a mile . I then stopped and let it tick over while we sorted something out and it went like normal afterwards . All I can think was that I didn't queeze the primer bulb when I started it to come home . It had sat on the beach all day with the motor fully tilted . Maybe i have the ignition advance issue too

[Easyrider]

Was you on 1/2 choke or no choke at all???

[Easyrider]

Re the carb settings- the bottom carb has a different size jet to the other 2 for some reason. The thundercat racers say, to set your carbs up, set them 1 3/4 turns out then adjust them accordingly until it idles ok then check your plug colour after a good run.

[ian parkes]

Originally Posted by Easyrider

Was you on 1/2 choke or no choke at all???

I started it with choke , and as usual pushed it back in right away after it started . i first thing i checked was the choke so not that . Why it should suddenly go well again after a short tickover I don't know. it was all a bit of a scramble gettin off the beach with my old mum on board the surf had picked up a bit and she was a bit scared ,
even better the other end we took a wave over the stern as we landed and mum just sat there in a beeched boat half full of water asking if she needed to help pump out

[Easyrider]

The reason i asked about the choke was that i noticed this sort of thing after i leaned the mixture out on the carbs. Before i leaned it out i used to start it with full choke (when cold) then push the choke in straight away and go-once it was leaned out a bit, it would be flat as you described it with the choke in but fine on half choke(when cold). I now allways start with full choke then run it on half choke for the 1/4-1/2 mile then shove the choke in. Runs a treat for me that way.
Have you checked your plug colours after a run yet?

[ian parkes]

Originally Posted by Easyrider

The reason i asked about the choke was that i noticed this sort of thing after i leaned the mixture out on the carbs. Before i leaned it out i used to start it with full choke (when cold) then push the choke in straight away and go-once it was leaned out a bit, it would be flat as you described it with the choke in but fine on half choke(when cold). I now allways start with full choke then run it on half choke for the 1/4-1/2 mile then shove the choke in. Runs a treat for me that way.
Have you checked your plug colours after a run yet?

Not much point looking at plug colour yet until I get it on 50-1 they are just a bit oily at present , but the uderlying colour when I clean the oil off isn't bad , probably a tad rich. The motor sounds rich , but the double oil mix must play hell with the jetting anyway.

Its really great to have a motor i can sort out and understand without a dealer and a computer .

[Easyrider]

Originally Posted by ian parkes

Its really great to have a motor i can sort out and understand without a dealer and a computer .

Exactly the reason why i brought mine- 4 months before i found a surfcat at a reasonable price!!! Sounds like we were the last two(for the domestic market) in the country to get our hands on them. Rescue services and race teams can still get them imported though.

Heres a link to the ign timing setup for our engines.


http://www.thundercatinflatable.com....2&d=1196750920

[ian parkes]

I checked the air screws today they were all set around 2.5 turns out , I tried them at 1 3/4 but the tickover dropped to 750 rpm and it didn't sound so good so i they are back to 2 1/2 again . certainly no issues with the wires interfering with the timing advance iether .
next thing i want is a bladder tank or a transom tank if one will fit. Just got to find a decent price on a bladder preferably .

[ian parkes]

I would really like to get this motor set up properly so to update this thread here's whats happened so far .

I called extreme marine to try and get a manual and some info . They told me to call tohatsu uk which i did . They just informed me that the motor should have a dealer first service after 10 hrs and they would set it up ok . So off i went for my service , and £60 later I am back to square 1 , i watched the dealer and all they did was rev it up and twiddle with air screws arriving at the same as me 2 3/4 turns out . Oh and £12 for the gearbox oil change .

Did a good run yesterday and it oiled a plug twice , no 2 first time as soon as we set off and no 3 about 45 mins later . After that it ran for 4 hrs no problem at all .

I called tohatsu again for some set up info and got to speak to someone very helpfull, the 2 1/2 turns out is standard on all carbs plus or minus 1/4 turn . There is nothing else to set .

THe mistake i made was running it in on 25-1 as tohatsu say , it causes oil to get trapped somewhere in the lower crank seal , and other than striping the motor it will take a good few hrs of running to clean it out . Often a bit of rough water or tilting the motor will release some oil and then a plug oils up . Which would go with yesterday when the second plug oiled after some lumpy water around a headland .
They told me they run them in on 50-1 and just don't use them hard for a
while .

Easyrider iam interested to know how you ended up with very different carb settings , we seem to be getting some opposing info .

Still waiting for the manual

[reinier]

I think the speed is too low for this setup... With a 360 rib tiller steered 40hp I used to get 39 knots. As I can see from the pics the engine has to be trimmed much higher. It will go much faster if you do so.

[ian parkes]

Originally Posted by reinier

I think the speed is too low for this setup... With a 360 rib tiller steered 40hp I used to get 39 knots. As I can see from the pics the engine has to be trimmed much higher. It will go much faster if you do so.

Not sure how you can see that from the pics . Maybe if i trimmed it out another hole it would go faster , but it would then slip in the turns very easily. where its set now seems to be about right for all round use .

I think this sort of speed is about it for any small rib that doesn't get the tubes clear of the water when on the plane .

I have not tried it alone with no load , could be much faster that way , but all i really care about is economy at about 20 - 25 kts which i have

[Easyrider]

Originally Posted by ian parkes

I would really like to get this motor set up properly so to update this thread here's whats happened so far .

I called extreme marine to try and get a manual and some info . They told me to call tohatsu uk which i did . They just informed me that the motor should have a dealer first service after 10 hrs and they would set it up ok . So off i went for my service , and £60 later I am back to square 1 , i watched the dealer and all they did was rev it up and twiddle with air screws arriving at the same as me 2 3/4 turns out . Oh and £12 for the gearbox oil change .

Did a good run yesterday and it oiled a plug twice , no 2 first time as soon as we set off and no 3 about 45 mins later . After that it ran for 4 hrs no problem at all .

I called tohatsu again for some set up info and got to speak to someone very helpfull, the 2 1/2 turns out is standard on all carbs plus or minus 1/4 turn . There is nothing else to set .

THe mistake i made was running it in on 25-1 as tohatsu say , it causes oil to get trapped somewhere in the lower crank seal , and other than striping the motor it will take a good few hrs of running to clean it out . Often a bit of rough water or tilting the motor will release some oil and then a plug oils up . Which would go with yesterday when the second plug oiled after some lumpy water around a headland .
They told me they run them in on 50-1 and just don't use them hard for a
while .

Easyrider iam interested to know how you ended up with very different carb settings , we seem to be getting some opposing info .

Still waiting for the manual

Update on my mixture settings-they are all at 2 3/8 now-i found that the throttle butterflies were open a fraction too far for a smooth idle.

[prairie tuber]

Originally Posted by Easyrider

Exactly the reason why i brought mine- 4 months before i found a surfcat at a reasonable price!!! Sounds like we were the last two(for the domestic market) in the country to get our hands on them. Rescue services and race teams can still get them imported though.

Similar situation here. We've got the Algore & his congregation of the brainwashed to thank for that!