low compression #2 cylinder - 1988 suzuki dt85

[so]

outboard is new to me. did compression test today. #1 and #3 have about 135 psi while #2 has only 40. looked inside the cylinders with an inspection camera, pics are from #2, not sure what to make of these, scores/scratches? All 3 cylinders have vertical lines.





i guess next step is to pull the head and take a closer look ? i have a service manual. Anything/gotchas i should watch out for during the process?

also, when i primed the fuel tank bulb, fuel leaks out of this hole in the bottom carb, what would cause that? will it carb rebuild fix it?



thanks.

 

[racerone]

Motor needs a rebuild.---Simple as that.-----And you need to correct what caused this or it will fail again !

 

[99yam40]

lack of lube or overheat
melted aluminum from piston on the cylinder wall

float not shutting off needle and seat causing fuel to come out the vent on top of carb

 

[racerone]

Repairing the carburetor takes very beer tokens and no time.-----The total teardown of the powerhead is going to take a lot of both.-----First see if 3 new pistons and machine work is available and in your budget !!.----Pistons may be hard to find.

 

[so]

can i rebuild just #2 with new ring/piston or all 3 have to be done at the same time?

 

[racerone]

Yes , you can bore out #2 alone.----But first see if you can find an O/S piston and rings.

 

[lakensea]

Pistons discontinued.

 

[so]

pulled head last night. all 3 pistons have the same pattern, they're "squished" to the left side of the cylinder while there's a bigger gap on the right, just that #2 has the worst score on the left.
what would cause that? i remember seller said before he inherited the item, his father-in-law had lay it on the side for several years in storage, would that have been the cause? but the score would have happened before going into storage.

cylinder head doesnt look too bad, right? no salt buildup or anything that would have caused overheating.

 

[racerone]

Motor likely ran hot.----Or issues with oil / lubrication.---Or wrong propeller.-Laying on it's side had nothing to do with it.----New owners and people invent new ways to destroy 2 stroke motors on a regular basis.-----Good luck finding repar parts.-----Find----browns point marine ----or ----evinrudeparts.ca ( now also Suzuki ) and see if they can help you.

 

[so]

will honing and new rings (all 3 cylinders) fix the low compression? will also troubleshoot/fix the overheating cause, of course.

 

[racerone]

The pistons are likely scrap too.-----Yes , you can hone and all that but a patch job like that will not get you a nice running engine.----Take it apart.----Inspect everything ( post pictures ) of piston skirts.----You will learn a lot !!-----If it was in long time storage the automatic oil injection could have had air leak in.-----Owners need to understand how these thing work.

 

[airshot]

By the looks of those cylinders, you will probably be better off finding a replacement engine. If the cylinders look that bad, I would hate to guess what the crank and bearings look like. Appears to be lack of lube in my opinion. If you have to pay for a complete rebuild...ouch, if your skilled enough to do all your own work...mabey cost effective!!

 

[so]

i've read that Suzuki and Johnson share parts or that some johnsons are actually Suzukis. Does my Suzuki have any equivalent Johnson models?

 

[racerone]

Your motor does not fit in that picture at all !

 

[racerone]

Some 5 HP 2 stroke Suzukis around 2000 were marketed as Johnson.---And some Johnson 4 strokes after 2000 were built by Suzuki.-----You will need to do some careful shopping to find parts for your " blowed up " motor !!

 

[99yam40]

take it apart to see what all is in need of replacing, then decide if it is worth try to repair it.
It is just your time that it is costing you

 

[racerone]

It happened years ago.-----Folks would come in with an outboard and say ---" I just bought it and it is not running very well "-------Still the same today.-----Very few good running motors are available by private sale !!

 

[so]

found these two powerheads on ebay,
1988 dt75

1988 Suzuki DT75 outboard crankcase block with intake | eBay

Find many great new & used options and get the best deals for 1988 Suzuki DT75 outboard crankcase block with intake at the best online prices at eBay! Free shipping for many products!

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1994 dt75, per crowleymarine, same powerhead as mine.
this one has good compression 120 all around

Suzuki DT75 75hp outboard crankcase powerhead | eBay

Find many great new & used options and get the best deals for Suzuki DT75 75hp outboard crankcase powerhead at the best online prices at eBay! Free shipping for many products!

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what do you guys think of the 'swap powerhead' plan ?

i paid $400 for the motor/control/power tilt-trim. bought it as practice project. Throw in another $700 for an used powerhead, worth it?

 

[racerone]

A very good option for you.------Keep this thread going as you make progress.

 

[so]

trying to take off powerhead but the lower rear
cover wont budge, i already removed the two bolts facing the transom (one on each side) and two bolts under the bottom cylinder. Tried gently prying with a screwdriver, no joy.






any idea ?