Suzuki Dt 9 9 Manual
Re: suzuki dt 9.9c 87 Hi there. I've also got a DT9.9C, also about 1988. I don't know how relevant this is to your problem, but anyway. I had removed the oil pump and was running premix for a while. I was concerned as every now and then there would be a small air-bubble in the oil feed line from the pump to the 'Y' joint where it connects to the fuel line. Dodge Ram 3500 Repair Manual. After removing the pump, I plugged the hole with an aluminium plate and gasket.
However, this was not enough, as the shaft driving the oil pump would rattle intermittently - and as you say, it sounds like it's coming from the top of the leg / bottom of the motor region. There's not enough room to slide it out with the engine cowling in place. Talking to a local Suzuki mechanic, having this shaft rattling loose long-term isn't a good idea, as it's driven from the crank and if it wears and/or jams, then that's potentially a big problem.
He suggested that if the plate could be modified to hold the shaft in position, but of course you also don't want to jam it tight. But the mechanic also assured me that he hadn't seen these pumps (Mikuni) fail.
1988-1997 SUZUKI DT8 DT9.9 DT15 2-STROKE OUTBOARD MANUAL. 9 95; Add to Cart. Buy and Download COMPLETE Service & Repair Manual.It covers every single detail on your vehicle. All models, and all engines are included. 1980 Suzuki GS1000 Service Repair Manual INSTANT DOWNLOAD. This 9.9 horsepower Suzuki outboard, manufactured in 1994, is a saltwater model. The engine weight is recorded at 77 lbs. This is a 2 cylinder model.
A replacement pump is still available new, cost around US$150. So if the pump is still in place in your motor, I'd be checking it out carefully. With pump removed, I set it up with the full tank above, check valve on the outlet in place, and ran it with an electric drill on slow speed connected to the pump drive (I used some heat-shrink tubing as a flexible drive and to connect to the screwdriver type head of the pump shaft). In operation the shaft is driven anti-clockwise, looking from the shaft side of the pump. This showed the same problem, the pump was pulsing properly, but intermittently some air would get in.
So I disassembled the pump. Remove two screws on the plate on the end of the pump. There's a small spring-loaded piston that slides up and down in a rotating cylinder driven by a gear from the drive shaft.
There's not a lot that can go wrong with these things. The pump 'pulses' when the main cylinder rotates, and the small piston is depressed by the raised ridge on the backing plate.
But when the piston drops off the ridge as it rotates past where it 'pulses', the pump sucks back a little. The check valve in the oil line between pump and fuel line needs to be working - it needs a little pressure to open - that's normal. I checked oil seal, and O ring on the backing plate for leaks under a little pressure, and they seemed fine. My problem was the hose between the pump and the check valve was old and hard, not sealing perfectly, so that when the pump 'sucked back' between pulses, a little air must have slipped in at the pump end connector.
I couldn't buy this thick-walled hose anywhere. Thinner walled hose is not going to work properly. Replacement hose and new clips were available from Suzuki. I replaced the other hoses as well, then reassembled pump hoses and tank, bench tested again. This time no problem. I've refitted the pump to the motor, running on 50:1 premix to be double sure. The new hose is much clearer, so I can see if air bubbles are in that part of the hose, not just if bubbles appear between the check valve and 'Y' joint.
I have run the motor for at least an hour in a tank, and no problems - no more air - the oil-injection system is working fine. I was looking at replacing this motor - auxiliary on my 25' trailer yacht. But the DT9.9C with extra long shaft, sail drive prop with conversion flange for rear-exhaust flow in reverse, electric start, and decent charging circuit would be expensive to replace.
- by admin