I have been having the problem where the pump stopped working after an impeller change.
The first thing I did was order another impeller from a different seller, and made sure that it said Genuine OEM part. Still had the same issue.
I had meticulously followed the instructions for changing, and rotating the shaft clockwise while bringing the top plate down over the new impeller.
it gets interesting here. I forgot to put the shift linkage access cover back on, and the pump worked and was pushing out of the telltale hole nicely.
I put the access cover back on and it quit pumping. Took it off again and it started pumping. :nono:
I read several forums and the consensus was that the exhaust from the motor was pushing the water back down the tube, and the pump would run dry.
NOTE: the pump would work when the access cover was off, because the exhaust vents thru the access hole with the cover off.
I found another forum post where the owner had contacted Suzuki, and the tech acted like”I’m sick of hearing about this” He told the owner to drill out the relief holes at the back of the motor at least two sizes larger and the back pressure would be reduced enough for the pump to work.
Sooooo – Suzuki knows about the problem and has no recall, no fix, and only an exasperated tech who tells customers to drill holes to relieve the back pressure.
My motor is 1992 vintage, but from what I read the DT4 had this problem for ten years with no recall, or instructions for a fix.
I finally found another owner who said he replaced an oil seal on the pump head, and that fixed the problem.
I went to the Suzuki Part page, and found the seal. It’s a - R91 Genuine Suzuki Marine 09289-10002 Oil Seal. Technically it’s not an Oil Seal since it seals the shaft and prevents exhaust gas from pushing water out of the pump. But so as not to confuse lets call it the Oil Seal.
Since the seal had broken down from either heat or water abrasion or both, I suggest buying a tube of lithium waterproof grease, and coating the “oil” seal when you install it.
While replacing the seal, I spotted another rubber gasket. This one “seals” the water line going to the motor, where it goes into the pump.
Suzuki calls this – The water Pump Case Grommet Part#- U28 Genuine Suzuki Marine 17415-98501 Water Pump Case Grommet.
I really think this may be more of an issue than the oil seal for the top of the pump housing.
You cannot see to line this tube up with the pump when reinstalling the lower unit, and I’m betting this is why the pump quits working when a new impeller is installed. Now that I know about this blind install, I am going to do my best to carefully install the lower unit with perfect alignment, and pray for success.
I am even considering smearing the shaft with flexible gasket sealer and letting it set all winter hoping it dries and forms an exhaust proof seal.
