suzuki 30 hp

rkoenigsma

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Joined
Jul 19, 2001
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20
i have a 1990 30 hp oil injected suzuki just rebuilt couple weeks ago. new pistons everything for $1200. it overheated due to not pumping water so we got a new impeller installed. it was pumping real good when we got it. when i ran it w/the ear muffs it would pump real good like in the lake. i ran it today to run the gas out of the motor and it wasn't pumping water good but a stream of water was comming out. will it overheat if not enough water is pumping out? i don't want to spend 1200 again to rebuild it.<br />the ear muffs were on right.
 

Trent

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Nov 17, 2001
Messages
3,333
Re: suzuki 30 hp

Did they replace the pump housing?? I also would check the thermostat?<br /><br />Some engines the rpm have to be up higher to show the tale tail stream (really good stream). Do you really know it overheated?? Steam?Did the Engine shut down ?
 

suzukidave

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Jul 1, 2000
Messages
387
Re: suzuki 30 hp

I have an 89 2 cyl 55 suzuki. I believe it's got the same lower end and water pump assembly. If so, you may also want to drop the lower end and check to see that the water pump housing hasn't cracked from the screws being overtorqued when you changed it, especially if you put the new impeller in yourself. Also, I assume you didn't run the tap at full pressure when the muffs were on -- that can mess up the impeller. One more thing, what, if anything, was wrong with the old impeller when it was changed?
 

enn888

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Dec 1, 2001
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Re: suzuki 30 hp

Have had the same engine (also a 1990) but curently run a 2000 DF30<br /><br />The engine has dual water intakes (the second one is behind the trim tap) You have to run the engine with plenty of water pressure on the mufflers - if not the pump will suck water and air (from second water intake) and the water flow will be iregular.<br />You can block the second water intake by tape etc. when runing on muffler.<br /><br />Probaly no damage has happened - the top cylinder is the one experiencing the highest temparature if you run the air/water mix.<br /><br />The warning system doesent trig on temparature - it is a flow switch that is placed in the middle of the cyl head and it will probaly not give any alarm when runing on a air water mix.<br /><br />The lower unit is completely different from the one used on the 55 and 65 hp model - but the 2 stroke 30 hp lower unit is the same as used on the new 4 stroke 25/30 hp model.<br /><br />The water pump housing is of SS and I have newer seen any of them crack - I guess the bolts and threads will break before the housing breaks. The housing is wery solid.<br /><br />I run my engines a lot (>300 hours a year) and the water pump on the 30 hp model are wery solid - used to change them every year - but as they look like new after one year I have decided only to service every 2/3 years.<br /><br /><br />(sorry for my bad english - I am from Denmark)<br /> :D :D
 

suzukidave

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Jul 1, 2000
Messages
387
Re: suzuki 30 hp

Enn388 I'm interested in your comments about small Suzukis from that era - you seem to have more experience than me with them and I'm guessing I might be asking you advice at some point. However, I think you are dismissing the chance of a cracked pump housing a little too quickly. My Clymer manual groups together all water pump replacements from DT30-55 from that era under one set of instructions and uses the same diagram. On the water pump housing cracking issue there is a specific warning in the manual for DT30-55 not to overtorque the screws or you will crack the housing. Also in the OEM installation instructions that come with the water pump kit for my Dt55 it says the same thing. Plus my dealer warned me about it last time I bought a new kit. I assume people keep pointing out this problem for a reason. Stainless steel can crack!<br /><br />I guess I'm saying you are probably right but if you are wrong then telling RKoenigsma to turn the water pressure up on the muffs is a bad idea.<br /><br />By the way, you are deinifitely right that I have a different lower end on the 55 -- I didn't have my manual handy when I posted and I have an oddball 2 cyl commercial 55 not a regular 3 cyl model and had it in the back of my mind from somewhere it has the next smaller bottom end than the 3 cyl. <br /><br />take care
 

enn888

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Dec 1, 2001
Messages
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Re: suzuki 30 hp

Well Suzukidave - I have had many OB and renovated a lot more.<br />My suZuki experience started with a DT 400 OB that was a 25 hp model from 1973 i Guess - a good solid engine the next one was a 65 hp 1982 model this was the last year the 55/65 hp models was made as 2 cylinders - also a rock solid engine had more than 1800 hours on when I sold it in 1991 (and I still see it from time to time - so it is still runing)<br /><br />After that I had a 3 cyl DT30 - a fast 30 hp engine (compared to other 30 hp models) it was a wery solid engine too - I sold it in 2000 and went to the 4 stroke area.<br /><br />I have the original workshopmanual incl. service bouletins for the 2 stroke 30 hp and for the 4 stroke 30 hp model - there is nothing mentioned about cracks in the water pumps. If you look at it it is of solid SST and seems to be more or less indestructable - but it is mounted on an Aluminium gearbox with SST bolts - if you tighten them to much they will break or the treads will be destroyed in the alu gearbox.<br /> :) <br />My e-mail is enn@REMpost7.tele.dk <br /><br />remove REM
 

enn888

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Joined
Dec 1, 2001
Messages
8
Re: suzuki 30 hp

One thing more - you wont destroy aything by turning the water up when runing on mufflers - the surplus water will expell from betwean the rubber muffler and gearbox - on the other hand you can damage the engine and Water pump by runing with to little water presure.<br /><br />On the 30 hp models (2 and 4 stroke) the manuals recomend that you put tape over the second water inlet when runing on mufflers - but it is IMHO not nessesary as long as you have good water flow on the mufflers.
 

suzukidave

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Jul 1, 2000
Messages
387
Re: suzuki 30 hp

Hey ENN388, <br /><br />So you had a 1982 Dt65hp 2 cyl. Do you know if it was just a carb difference between the 55 and 65hp models back then? I'm wondering to myself if maybe it's the same powerhead as my 1989 2 cyl (798cc) in which case maybe I can coax a little more power out of it if I find some old DT65 carbs. <br /><br />It's also a loud crude tank of a motor with plenty of hours by the way -- and I love it and expect to run it a long time. The water pump looks like brand new each time I drop it (every two seasons or 200 hours).
 

enn888

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Joined
Dec 1, 2001
Messages
8
Re: suzuki 30 hp

The Diff from the 55 to the 65 was not only carb. jets - the 65 had larger bore (= more cubic.) And as I recall it had a different ingnition timing.
 
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