What tick over RPM should I expect? - Perkins 4107

[FionaJC]

I recently re-engined and replaced a Peugeot XD2 with a Perkins 4107 diesel engine. The engine is in and runs perfectly. I took the boat out today for a drive around before we started sailing and all appears wonderful.

Now the problem is that the tick-over is 1000 rpm stationary or driven, hot or cold. I feel that this is too high as it drives me at about 3knots and makes berthing on a pontoon a bit fast and interesting.

before I look at reducing this to 400-600 I would like to ask you all the following questions;

• Those of you with Perkins 4107 /8 /99 what is your tick-over in RPM?
• If I tweak it down to 400-600 what are the dangers?
• My Chrysler Grand Voyager car also runs at 1000RPM. Is this new standard.?

My boat is a 6.5 Imperial Ton 34ft ketch. The XD2 was 75hp 2.3litre and used to bury the stern in the water. One day it refused to start and after examination the marine engineer said change the engine. I did, its quieter, more steady, doesn't shake everything and hopefully more economical. I will also no longer be the only person in the region with an engine no one knows.

[donradcliffe]

By and large the engine will tell you what idle RPM to use. As you reduce the idle speed, several things are likely to happen.

!. The engine is going to start shaking.
2. It is more likely to die. There is an anti-stall device in the injection pump, but the slower the idle setting is the more you are asking of it. My 4108 used to die after running hard and then suddenly throttling back, but that was fixed by rebuilding the governor. The real test is to have the boat going near hull speed forward, then shifting into reverse.
3. The low oil pressure alarm is going to start chirping.
4. The alternator is going to put out less amps.

Increasing the idle speed will help with 1-4, but there will be louder crunching noises when you shift into gear, which can't be good for the transmission.

My tach wasn't accurate after I changed the alternator pulley size, but I think I ended up about 750 rpm.

[boatbod]

700-750 rpm is about right for a diesel

[Suijin]

Something is wrong with your Chrysler. You should be down around 800.

[Emmalina]

All the perkins books I have say 650-750 and my 6354 is the same !

[Diesel Bill]

First check that the throttle cable is returning all the way to idle on the engine govorner speed control linkage.
If that doesn't do it there should be a screw controlling the idle that you can back out to reduce idle speed.