Suzuki DT2.2 Problem?

[xeitosaphil]

Hi wondering if anyone might know some aswers?
I haven't used my Suzuki D2 for a couple of years now, its been on the pushpit waiting for a chance out.
I intended to use it in the future while away, but thought to bring it home to check first, if it still works ok, before finding out on the dinghy it doesnt. It was working fine the last time I used it, and it used to start first time.
I took the spark plug out and checked that was ok by earthing it on the engine and pulling the starter cord, all ok.
I removed the fuel tank and the old fuel, cleaned it all out with fresh fuel, replaced it, and tried to start it.
When turning the fuel cock on, loads of fuel runs out behind the throttle face plate, I wondered what might cause that?
I removed the black throttle face plate in the hope of getting a look inside the carburettor.
The throttle linkage goes up and down as normal but cant see if the needle goes fully down. I assume it goes down and shuts the fuel off, but not exactly sure how the workings of this carburettor works.

With fuel still dripping and the fuel cock turned off, I can start the engine after a few pulls, and it will run as long as I don't fully open the fuel cock again. It will run ok, but then it starts to increase revs until I have to shut it off with the stop button.
I Thought to try and take the carb off but can't get to the two screws at the top as there is the electric thingy fixed above them in the way.

Do you think that fresh petrol overnight might free any gunge that might be affecting the carb needle if that is the problem?
Or could it be something completely different?

Sorry for the long post, but any suggestions would be appreciated.

Thanks Philip

 

[VicS]

Hi wondering if anyone might know some aswers?


Sorry for the long post, but any suggestions would be appreciated.

Thanks Philip

The needle valve is probably stuck open (#27 in the diagram below).
Or possibly the float (#29) is stuck
These control the flow of fuel into the bowl

The needle (#20) you have been looking at is the metering needle which controls the fuel flow to the cylinder with varying throttle opening

 

[xeitosaphil]

Thanks Vic for your reply and explanation of the part numbers.
Is there anyway I might free either of those suggested parts, other than taking the whole carb apart, which means it looks like stripping half the engine apart to do it.
I have some spray can carburettor cleaner, if I squirted a lot into the opening of the carb do you think it would do any good.
I assume the carb is now full of fresh petrol and wondered, and hoped, that the petrol might do the same thing over night?
What do you think?

 

[VicS]

Carb cleaner sprayed into the air intake wont get anywhere near the parts in question.

Maybe when soaked in petrol overnight they will come free.

With the engine covers removed can you not access the two screws, #34, which hold the float chamber (un-numbered) on?

 

[xeitosaphil]

Carb cleaner sprayed into the air intake wont get anywhere near the parts in question.

Maybe when soaked in petrol overnight they will come free.

With the engine covers removed can you not access the two screws, #34, which hold the float chamber (un-numbered) on?

My engine looks exactly like the schematics you posted, other than the screws in question are not underneath the float chamber, but are screwed down from the top of the carb for some reason? Perhaps mine was an earlier version which was upgraded over production timescales?
All the electrical stuff is fitted above the carb and also the throttle leaver asembley which is why I can't get at it to unscrew the carb without removing all that first. I only worry that disturbing all that might create other problems as the engine is quite old I think?
Is it possible to remove the carb by unscrewing the bolt by the washer No24 that fits it to the cylinder head or is that also asking for trouble.

Thanks Vic for taking time to follow this post.

 

[xeitosaphil]

My engine looks exactly like the schematics you posted, other than the screws in question are not underneath the float chamber, but are screwed down from the top of the carb for some reason? Perhaps mine was an earlier version which was upgraded over production timescales?
All the electrical stuff is fitted above the carb and also the throttle leaver asembley which is why I can't get at it to unscrew the carb without removing all that first. I only worry that disturbing all that might create other problems as the engine is quite old I think?
Is it possible to remove the carb by unscrewing the bolt by the washer No24 that fits it to the cylinder head or is that also asking for trouble.

Thanks Vic for taking time to follow this post.

Vic I tried the fuel tap after carb full for 24hrs with fresh fuel, still the same problem of fuel just flowing out of carb front.
Here is a couple of photos of the screws I can't get to unscrew to remove the float chamber. Any suggestions apart from stripping the whole top end down to get access?

 

[VicS]

I see. If I'd read the title of your post properly I'd have realised it was a DT 2.2 not a DT 2 and would have concentrated on the 2.2 parts diagram (All the earlier DT2 models have the carb bowl screws fitted from underneath)

It looks as though you will have to remove the the whole carb.
With the covers and the control panel removed shut the fuel cock and disconnect the fuel hose from the carb fitting.

Slacken the clamp screw

.................................................. and remove the carb. ( use a new O ring when refitting)

When you remove the float chamber you will probably find it has all freed itself but check that the needle valve does seat properly. Clean the needle and seat if necessary or if in doubt renew them.


(BTW the "electrical part" you referred to is the ignition coil. )

 

[xeitosaphil]

I have managed to remove the carb bowl without having to strip everything down, with a mini ratchet 1/4 hex wrench, with a screwdriver bit in it, which is s great result.
The bowl had a lot of solidified sedement in it and the float had a build up on one side. Cleaned both up and used loads of carb cleaner sprayed everywhere, also checked float is rising and falling with ease.
Refitted everything and now engine is back to normal, no petrol leaks from carb and runs first pull. Don't know where the needle valves are, as nothing seems to match the schematic?
On very close examination of schematic and photo of the carb, the carb isn't actually the same as schematic?
There is no No 27 inside the carb float chamber, or a No 40 mounding on the outside of the body?
It has MIC cast into the body and a number 984FO stamped into the carb body.

I've attached a couple of photos for your interest?

Thanks very much for all your help Vic, much appreciated. Cheers Philip

 

[VicS]

Glad you got it sorted.
In future shut off the fuel and run the engine on a fast idle until it stops if the engine is not going to be used for a while.

I would have removed the needle valve and its seat to be sure they were clean and that the valve was seating properly

Below is the diagram for the carb fitted to the DT2.2 (the needle valve and seat assembly is #27)

 

[Avocet]

I have a DT 2.2. Its easy to drain the float chamber of fuel after shut-down, by taking out screw 37. You don't need to take any of the engine cowling off.

I agree with Vic. The "flooding" of the float chamber is almost certainly the needle valve (Item 27) and its seat. Best to replace as a pair.

 

[DOILY]

Flooding on my 2.2 Suzuki was caused by a moulding defect in the float allowing it to fill with fuel.