Need some Suzuki master to nail this

Joined
Nov 23, 2017
Messages
8
ok pulling my hair out with this now, need help !!
I have a DT65 Suzuki oil injection, I think its 1980s cant seem to match serial number for precise year. Anyway. Bought this motor and the guy I got it from said it needed a bit of work to get it going and explained it had an issue with water leaking from head. He wasnt wrong !! Head Gasket.
What ive done so far.
New Head, and Water cover gasket. Full carb clean. (twice Actually) a good detailed clean at that. Reed valves looking good too. Oil filter cleaned was in good condition. New spark plugs set to 0.9. NKG,s. Fuel pump rebuild. Though I dont feel its needed, I have ordered new diaphragm anyway. in post now. Thats another thing eliminated. adjusted mix screws 2 turns out. new fuel. New oil. And start... Success, She kicked into life. Put it on muffs and all seemed well. Went into gear up and down revs ok, so took it to local lake for a test spin.
launched after a quick start at bank and all seemed good. Maybe sounded a little rough, but was thinking I will tune it out on water. As soon as I gave it a bit of throttle she dies. Sounded like it was starved, So I tried again and it started up ok this time, will even rev up in neutral. Managed to tickle it up a few revs but then felt like it was limited or restricted.( I will come back to this) I had a quick look seen that the plug was wet with fuel. Initially I thought must be spark problem.
Took boat back to yard, back on muffs and discovered that its only running on 2 cylinders, top cylinder is not firing. changed around the HT leads and problem remains in No 1 cylinder. (ruling out HT leads or coil issue). I have a compression tester coming to do full test in a few days but I am certain ive got good compression and good fuel and good spark. I did noticed that the spark on cylinder 1 gave me a bit of a shock and spark was jumping outside of plug to my hand. sort of all over the place when I touched it, a bit different from the other 2.
My question is this, what would cause a miss in one cylinder if you have compression, spark and fuel. where should I look next to get this cylinder to run. I was thinking maybe magnetos. Timing am I on the right path. If anyone can shed any light it would be a massive help.
Also Coming back to Oil injection issues. Can someone shed any light on the oil sensor limiting revs. I dont have a rev counter but im sure its holding around 2000rpm when it does go on the the 2 cylinders. Its full of oil and the oil light is still showing. Thinking faulty sensor. However I tried to by pass sensor by joining plug wires telling system level is full then hit the reset button while engine was running and this didnt put the oil light out. Again any info would really help me not go bald.
Thanks for sticking with me and hope there is some expert guy out there that can teach me a few things.
 

mphelle8vld

Petty Officer 1st Class
Joined
Aug 17, 2005
Messages
321
Good first post with lots of info but there were lots of changes in that model between 85-90. Please post the serial number and photos, it will save us a lot of time.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
I would think if spark is jumping where it should not then the plug cap/wire is bad, it should keep the electrical flow inside for onlt the plug to use
 

tommarvin

Ensign
Joined
Nov 22, 2015
Messages
999
I would get a spark checker and make sure spark can jump one half inch on all spark plug wires.
Ground all other spark plug wires when doing a spark test.
Test all spark plugs with multi meter, it's on you tube,continuity and resistance should be around 4.3 when set to 20kohms.
The spark on cylinder 1 should have knocked you on your butt ,or stopped you heart from beating. Dont get shocked from spark plug wires anymore, be careful get rubber gloves.,
 
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