Suzuki DF 25

[mjatkey]

Hi,
Took RIB out of garage at weekend and ran Suzuki DF 25Hp up on muffs. Tell tell seemed fine on first run up but once I'd put the cover back on etc and cleaned it all down, quick pull and guess what no tell tell.
I tried the obvious, pulled out the tell tell spout but no joy.
Outfit was new to me last summer and I had new impeller fitted before putting it in the water
The mechanics who did the impeller said thermostat was jammed open but did not replace it at the time and said it was best to run with jammed open thermostat than none at all.
Engine was flushed every time it was used (probably only 6 in total) and was garaged all winter.
Is it the impeller again and if so why has it gone so quickly.
I have a 2.5 which I use on the kids dinghy and thats never had impeller change in last five years, again gets flushed after every use. Thanks Martin

[Boats&Outboards]

Take the stat out and run it. Water will most likely pump.

Then replace the stat for new! For what they cost I'm surprised the engineers did not replace it or advise you to if they did the impeller.

[mjatkey]

Thanks will give that a go.

[9D280]

I would agree it's better the 'stat be jammed open than closed.

For what it's worth, when I did the rebuild, I discovered that the later models of mine did not have a thermostat or poppet valve, so I rebuilt it without either. Yes, it runs a bit rougher at idle than it used to when cold, and I need to use the fast idle lever on cold start which I didn't originally have to do, but for long term reliability..... time will tell, but it's now got two less things to go wrong.

[mjatkey]

Yes I was thinking along those lines but from other forums on web the overall concensus is that it should have a fully working stat, so will order that and another impeller.
Thing I still don't get is why should the impeller only last 9 months and why did it appear to be working on the first run up.
Could there be an underlying overheating issue with this engine? Thanks Martin

[Boats&Outboards]

When running it with the stat out did it pump ? If it did you may not need the impeller just the stat.

Peter @ Boatsandoutboards4sale ~ askboatsandoutboards4sale@sky.com ~ 07930 421007

[aquatec]

In a four stroke engine you should always have a working thermostat. If you run an engine either without, or jammed open, the engine will run much too cold. This leads to a build up of condensation in the engine block and emulsification of the engine oil. Which in a worst case will seize the engine due to rust or lack of lube.

You do not say if you have the earlier three cylinder DF25 or the current V twin. To change the stat in the early engine is easy as it is on top of the block, just four bolts and the cover is off. If you have the current engine it is more of a fiddle as the stat is in the vee of the block below the inlet manifold and carb but you can do it. I will say, your mechanic should have tried to unjam the stat as it is sometimes caused by a bit of salt corrosion blocking it open then testing it. Or it should have been changed. We carry the parts in stock, call me or pm me.
Aquatec
01903 762610