1 photo
Suzuki DT40

Suzuki DT40 Questions & Answers

5.0 from 2 reviews

5 questions from our users

John M

John Masked

What is the oil ratio on a DT40

1 answer

I have a dt 40 and run 50:1

Ben L.

Ben L.asked

I’ve had great difficulty downloading a manual for a dt40 04005 - 410028. Suzuki website stops loading and boats.net doesn’t seem to have that model listed.

No answers
Todd B

Todd Basked

Hey i have 2016 suzuki 40hp fourstroke it keeps breaking down untill i pump fuel pump have replace all fuel lines. Any ideas?

No answers


Why does my suzuki 15 hp 2stroke outbourd moter run roughly with new fuel

1 answer

Assuming you are using the correct ratio, and you've cleaned your carb out thoroughly, then it's possible you are getting contaminated fuel. Some fuel has bioethanol in it, which can absorb water from the air or the tanks in which it is kept. A gallon of fuel can absorb up to four teaspoons of water in suspension.

It's a major problem for boaters. Your local chandlers should have fuel treatments that can handle small amounts of water, they also stabilise your fuel. Any more than that and you need a water separator, but I would concentrate on making sure your fuel is clean. Mae sure the additive is ethanol (E10) compatible.

If the problem is not water, test your compression on each cylinder



I have a 1 year old DT40hp Engine and is already giving me a hard start problem. It takes more than 10 pulls to finally get the engine up and running. Also engine cuts off when slow down completely and when shifting gear forward, neutral or backwards. What has caused these to happen?

1 answer

Most likely suspect is the carb either has water or muck in it. You need to take it off, clean the outside thoroughly in jizer or parrafin, and then remove the float bowl, you should see any sediment in the bottom. You need to carefully slide the float pin out and remove the float noting that the fuel inlet valve inner part is attached, check this for signs of wear. Then you need to remove the main jet and the air screws, but note how many turns out they are before you remove them so you can set them back correctly. I then use an air line and blow it through all the passageways. Once you are happy its thoroughly clean reassemble carefully making sure everything goes back where it came from and that the adjustable screws are in the original position. I'm assuming you checked you plugs an ht leads. If you find crud in your carb then you need to clean the fuel line and pump out too and replace the filter. Use a marine fuel saver additive in your petrol which reduces oxidising of the fuel and moisture content. Some fuel supplier have 10% ethanol in the petrol which can uptake moisture, which then causes problems in marine engines, fuel saver additive helps greatly.

Get an answer from our members

ProductReview.com.au has affiliate partnerships. These do not influence our content moderation policies in any way, though ProductReview.com.au may earn commissions for products/services purchased via affiliate links.