| Author |
Message |
    
graham edward sheppard
New member
Username: hambo
Post Number: 1
Registered: 11-2009
| | Posted on Tuesday, November 03, 2009 - 03:05 pm: | 
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hi...can anyone tell me if it is possable to increase hp on the 9.8hp tohatsu..i have a 2.7mtr twin skin hull rib and could do with some more power..the outboard is not that old and i like it and dont want to part with it but am well up for a tweak..not bothered about mpg..maybe a little on reliability..but am mechanicly minded so feel im up for the challenge!..regards..ham |
Tohatsu Guru
Senior Member
Username: tohatsu_guru
Post Number: 1038
Registered: 06-2007
| | Posted on Tuesday, November 03, 2009 - 03:26 pm: |
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Nope. The 9.8 is at the top of the food chain on that frame size. |
graham edward sheppard
New member
Username: hambo
Post Number: 2
Registered: 11-2009
| | Posted on Wednesday, November 04, 2009 - 04:50 pm: |
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thanks for getting back mr guru...i hear what your saying..guess all i can do then is a high thrust prop..if so what would you recomend..more pitch/four bladed????im not a huge lad but the boat wont get up on the plane with 2 of us in it to my suprise i bought it for this purpose and are just looking at ways round the situation without forking out again! dont know if its just on the two stroke model but heard of a 9.8-15hp conversion which was more economic than buying a bigger outboard, have you heard of such a thing??...thankyou so much for your time...ham |
Tohatsu Guru
Senior Member
Username: tohatsu_guru
Post Number: 1041
Registered: 06-2007
| | Posted on Wednesday, November 04, 2009 - 05:52 pm: |
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There has never been a conversion from 9.8 to anything larger. There is a conversion on the 9.9 to 15.
The four bladed prop is for pushing a 4000 lb load so you would not use that one. Think in terms of an 8 pitch or a maybe a 7 pitch. I would suggest the 8, but you need to keep in mind that a tiny inflatable of that size would be difficult to get up on plane due to the stern weight. The second person needs to be sitting forward as much as possible and you need to really make sure the tubes are at 3 + PSI...Add air 15 minutes after the boat is in the water. |
graham edward sheppard
New member
Username: hambo
Post Number: 3
Registered: 11-2009
| | Posted on Thursday, November 05, 2009 - 12:27 pm: |
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sounds good mr guru...and just .1 of a horse out of size...hows ya luck!..ok will try the 8 pitch..like i say she planes a real treat with just me in it and sits at 22mph nicely....i use the boat for carp fishing on the rivers in france mainly and carry alot of kit with me. on route mainly isnt the room for two persons comfortable but is alot of weight...just out of curiocity and cat killing would the four bladed prop be just too much..aka..have maybe the power but loose the rev..over propped..or not have the power make the engine work like hell get very warm and not be happy...and go slower than the 8 pitch although have the thrust??...whilst we are comunicating..i did have the tohatsu sail drive 5hp 2 stroke lovely engine and was wondering do you happen to know what the charge coil is that i would need to install in to my 9.8, as unlike the 5 it doesnt seem to have one fitted, i need to charge a 12v battery which powers echosounder and lights??...thanks once again for all your sound advice...shorly you should be called the oricle and the guru!! regards ham |
Tohatsu Guru
Senior Member
Username: tohatsu_guru
Post Number: 1043
Registered: 06-2007
| | Posted on Thursday, November 05, 2009 - 12:50 pm: |
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The four-bladed prop would activate the rev limiter putting the engine into a low RPM running condition that can only be corrected by turning the engine off.
Do you have an A, A2 or A3 model? |
graham edward sheppard
Member
Username: hambo
Post Number: 4
Registered: 11-2009
| | Posted on Friday, November 06, 2009 - 01:14 pm: |
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errrm...leave it with me ill find out..i dont have it close to hand as i live in a flat...ill have a look....spk real soon.. |
