This year for hols we're renting from a notable professor in the sciences. I always ask loads of detailed questions to ensure we're not going to be stuck next to a sewage treatment works etc. I loved his reply which started... "A lengthy note but all sensible questions and well explained". I award you this phrase too.
Re the new 4-stroke or ten year old 2-stroke. Either is good... neither is wrong. A decision that can go either way depending how the wind blows. For me the quietness of 4-stroke when trolling in wildlife areas or on rivers plus the economy improvement which increases range by 30%-50% for the same tank capacity and saves carrying a second tank on long days out are major factors. ECU controlled cold start mixture/idle speed is far better than a choke too giving the same stability of idle at a set speed from the second it cold starts to when hot mid summer.
Makers are already changing to efi in the 15/20hp and above ranges. I think Suzuki were first with their 20hp 5yrs ago. Now Tohatsu and Mercury/Mariner have followed suit.
Re Diagnostics... Have a look at the thread with screenshots where you can see the dealer level info taken from the laptop. CD software and lead good value around £55.
http://www.rib.net/forum/f36/suzuki-...tml#post767629
So yes the outboard version of OBD2 except as far as I know it is all maker specific whereas with cars you can get the basic engine data for any car on almost any reader.
I know VCDS. I don't have it but do have an advanced handheld reader for VW/Audi as daughter has a VW... I look after all family cars. This will do 90% of VCDS in error codes, deeper diagnostic, live data inc graphical etc but not component coding.
I have dealer level diagnostics for my own car plus a make specific handheld... and a advanced make specific handheld for Mrs F's car. All of these have basic OBD2 which is what I use for daughters Jazz which so far hasn't needed extended system diagnostics.
Years ago folks said cars were becoming too complicated for DIY because of all the "computer stuff". In reality if you have the diagnostics then home maintenance is actually easier than in the pre-ECU days.... and so it is for OBs.
Re timing belt... My level of experience is substantial over a 44yr period (just too modest eh) so a 20hp OB timing belt is a doddle compared to say a twin OHC transverse engine car with tensioner, idler pulleys and timing belt driven water pump... and less than the thickness of your knuckles between components and inner wing!
On the Suzuki the belt just goes over two pulleys and once the pull start is removed and flywheel is pulled off just a case of lining up marks and swapping belts.... no tensioner or anything else to deal with. Probably the only tool needed is a generic flywheel puller. I have several such tools and come the time I'm sure one will fit.
Belt itself about £20... no idea of labour but I wouldn't trust my nearest dealer to fit it.
I know folks who suffer timing belt anxiety. I've never had one break on a car but I always change on time and get the procedure spot on. I have no worries about them. Having said that pleased that now 3 of our 4 cars have chains... it just saves a fair amount of faff at 3/4yr intervals with some.
As a matter of interest from DF40 models upwards Suzuki have gone for timing chains with hydraulic tensioners and these only need looking at every 5yrs and probably never replacing if oil changes with the correct quality lube are carried out routinely.
Re injectors... Like timing belts I have no concerns. The 4 family cars I look after have 18 injectors between them and share a total of 500,000mls on the originals with no issues. Use clean fuel and drain/change filters when needed and trust them as much or perhaps more than a carb.... because when efi OBs are stored the small amount of fuel to them is in a sealed pressurised system... so no issues of fuel absorbing moisture or evaporating to leave gum deposits behind.
I am more aware of fresh fuel with efi though and fill the OB tanks prior to an outing or holiday and then sell the surplus after an outing to my daughter (the only petrol car on the drive)… so it's always running on fuel no more than a week old.