Two stroke or Four stroke??
Not looking to start the usual but have more of a specific ?
Considering repowering
Looking at the Yammy F70A fourstroke.
Also considering a Yammy 90hp two stroke - most likely will get the four as quieter and less fuel. Holeshot better with the 2 stroke but this is not a huge issue for me the 4st will push it along fine anyway (and top speed will be faster than the current motor which is getting close to its useby)
Weight is roughly the same and not an issue.
4 stroke definitely better on fuel and quieter.
My question is I sometimes don't use the boat for long periods so in this regards are there any problems with the 4 stroke sitting idle for periods between use - is stored elsewhere so no always very practical to just give it a run on the muffs now and then.
Cheers
Paul
Youtube Channel - FishOnLine Productions
https://www.youtube.com/channel/UCbUVNa-ViyGm_FTDSv4Nqzg/videos
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tim-o
Posts: 4657
Date Joined: 24/05/11
Shel be right, maybe use some
Shel be right, maybe use some fuel stabiliser, recommend running premium all the time also
I am, as I've said, merely competent. But in an age of incompetence, that makes me extraordinary.
SpotHound
Posts: 439
Date Joined: 06/02/14
Honda
My honda has sit for up to 18 months and started first pull.
Run carby dry and you will get no deposits left to gum it up, 2 strokes would be bad for that.
Rob H
Posts: 5798
Date Joined: 18/01/12
the 70 is an EFI-probably
the 70 is an EFI-probably better not to run it dry if you can help it
Give a man a mask, and he'll show you his true face...
The older you get the more you realize that no one has a f++king clue what they're doing.
Everyone's just winging it.
clogwog
Posts: 265
Date Joined: 01/02/11
Mate, I re powered with a
Mate, I re powered with a yamaha 90 2 stroke recently, I chose the 90 as I could not justify the extra cost of the 4 stroke engine, plus I was repowering an old hull. I have been really happy with the engine, runs quiet, does not let out a huge amount of smoke. I would have preffered the 4 stroke but still very happy.
Brock O
Posts: 3227
Date Joined: 11/01/08
I have a
2 stoke 07 - 115 merc, to me the fuel use is good with great power.
Due to it being part family boat, the occassional smell of smoke is the only negitive comment it gets.
cutter
Posts: 150
Date Joined: 30/12/10
4 stroke
defiantly go the Yamaha 4 stroke iv got a 50hp yammy 4 stroke on my tinny and a 225 hp yammy 4 stroke on my 7 meter both don't miss a beat and great on fuel
Paul H
Posts: 2104
Date Joined: 18/01/07
Cheers Guys, Had already
Cheers Guys,
Had already sold myself on the (injected) four-stroke going to use 1/3 of the fuel of the current motor so will extend my range considerably.
Was just wondering about any possible issues with lack of use so thought the ? was worth asking.
Services will be annual and will run some injector cleaner in the fuel now and then. If going to be left for a while I'll pour any fuel into the car and get a fresh batch for the next outing (easy enough as I have portable tanks).
Will be running 91 unleaded as a few places I go only have 91 or diesel (car is tuned specifically to 91 as well).
Got a pretty good price so not a huge gap between the 2 and 4.
Cheers
Youtube Channel - FishOnLine Productions
https://www.youtube.com/channel/UCbUVNa-ViyGm_FTDSv4Nqzg/videos
sstevee
Posts: 472
Date Joined: 15/11/11
I'm no mechanic but I would
I'm no mechanic but I would think the effect of not using it would be pretty much equal... The two stroke would be oil injected (I'm assuming) so if it sits for a while the fuel may evaporate and leave oil residue which could varnish up... The four stroke will have oil in a sump which realistically should be ok over time (if not being used) either way I don't think I'd let the lay-up time determine 4 or 2 stroke
Ian S
Posts: 71
Date Joined: 20/01/14
4 v 2 stroke
If its an oil injected two stroke the fuel evaporation really isn't an issue as there is no oil in the the fuel. I have an Optimax 115 and to lay it up you just drain the fuel out of the bowl (two drain plugs are provided to get it all out)then next time you use it, pump fuel up with the bulb turn the key on and let the electric pump build up pressure and it starts straight up. The evaporation issue was more to do with premixed fuel and also the older motors that pumped oil into the fuel as it went into the carby. Just to clarify, the Optimax has direct fuel injection into combustion chamber and injects oil into the airflow going through the crankcase to lubricate everything. Seems to work well and according to Mercury figures has better fuel consumption than the Mercury fourstroke motors.
petermac
Posts: 2946
Date Joined: 03/03/10
on fuel
I was out last Tuesday and probably did at least 130 km maybe 140 on my 5.3 northern fisher stacer it has a 80hp 4 stroke yamy on the back I fueled up on the way home 67 liters used and most of the time it was WOT