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View Full Version : 90's model Mercury 200 improvements and mods??



mart686
06-01-2007, 11:22 AM
What would you suggest as improvements to a fresh 1999 mercury 200. Already has low water pickup and lower unit, also, modified exhaust tuner. What other reasonable mods will produce extra performance and associated costs outside of boring the motor out with bigger pistons? Thanks for your help. MN

pyro
06-01-2007, 12:12 PM
There's all kinds of things that can be done. Do a search, there's tons of details already archived here. Start with tighter heads and re-jet. You can also do port work and other major mods, but you may sacrifice low-end power and reliability of stock parts.

If you want significantly more power and RPM range, investing in a real race motor might be worth it.

hsbob
06-01-2007, 04:18 PM
next cheap mod if to have the heads cut. will add to low and mid preformance. provides a good base for you next costly mods. negative is the need for hi test gas.

tindell1
06-02-2007, 11:45 PM
Heads give about the biggest bang for the buck. Get your heads cut to 31cc, that way you can still run pump gas. Make sure you are using spark plugs that have can be gapped. You can look at them after you run it to tell if you need to change the jets. If the insulator is "cardboard brown" that is the leanest you need to go I would not recommend running it like that. The safest bet is to get a set of pyrometers. That way you can check your exhaust temperatures. Checking the plugs is an old school method but works. Lightweight flywheels add improvement. velocity stacks on the carbs help. There are numerous things that can be done, it just depends on how much you want to spend. If you want to make big changes then I would not mod your current motor, I would do as Pyro said change motors. 260's are not expensive and will give you alot more power and reliability. stock.

hope this helps.

Tim

150aintenuff
06-03-2007, 04:50 AM
on a 99 you can do an air intake mod to rais the back and form a scoop and cut in some 2" holes under it to allow air flow... also disable revlimiter and remove oilinjection is almost a must... heads also a must no smaller than 35 cc.. or 145 cranking compression... for 92... intake spacer, sportjet front half and 5 petal ruber coated reeds. port match the chest, adapter, tuner. port the intake do the rod slots, if its apart do a full ballance to atleast .1 gram on the rotating assembly. velocity stacks dont gain anything to speak of... tuners sometimes do overall even built up to 250ish hp that 200 will outlive the 260s any day... no nicasal to wear off rings... steel borz are so much nicer to build..

pyro
06-03-2007, 07:00 AM
...but people with heavily modified steel bore 200's also seem to be scoring cylinders and blowing them up on a regular basis. Nicasil-coated High-performance motors were actually designed to turn 7000-7500 rpm all day...

150aintenuff
06-03-2007, 10:24 AM
...but people with heavily modified steel bore 200's also seem to be scoring cylinders and blowing them up on a regular basis. Nicasil-coated High-performance motors were actually designed to turn 7000-7500 rpm all day...

maybe so but steel is boreable and cheeper than a sleeve..

tindell1
06-03-2007, 11:21 PM
When you start to weigh out cost versuses reliability. All those mods will give you what you can have with a stock 260 EFI and cost more than you can buy a good 260 for. Plus no worries about them dang carbs. Dont get me wrong you can mod the 200 block but those 260's are almost bullitproof. I have not modified a 99 200 all the ones I have done have been 2.4 200's but the same principles apply. Anyway the final decision is up to you. But please at least if you are going to run that 200 for a while take off that oil injection before you have to make the decision sooner rather than when you are ready.

Tim

mart686
06-04-2007, 10:22 PM
Thanks for all the replys and info. As for the oiler, already disconnected by current owner. From what it sounds like, motor is better left alone for the most part. A 99 with only 30 hours on it is rare and should be fairly easy to move to the OB market or bass boat market. I will just use as is and try to trade over the winter. If anyone heres of a deal or possible trade, send them my way. Mart Nesbitt 828-777-3851.

mercpunk
06-04-2007, 10:27 PM
die grinder = $25 .... carbin grinding bit $30 ....

being faster ...... PRICELESS

Dave S
07-20-2007, 09:29 PM
Stone grinder......$1.09 :D

towman2277
07-20-2007, 09:54 PM
die grinder = $25 .... carbin grinding bit $30 ....

being faster ...... PRICELESS
Thats a good one man!!! :D :D :cool: