Carburator problem - XR2 - Page 2

Mike_G · 29-05-2007, 09:21 PM

I don't know, I have set floats by the book 1,6mm up form carb body and when I pumping fuel into it everything is ok but when I start engine it starts to overfills. I don't see another problem in my carbs so I will try to put those pumps back in bussines and will see how it works

scottyboy · 29-05-2007, 09:33 PM

Quote:

Originally Posted by Wayne Kerr

Which of "those pumps" are you talking of here SB?

The "accelerator" pumps on the side of the carb on some xr2's. The part number 24 on Mike g's link is part of it.

scottyboy · 29-05-2007, 09:35 PM

Quote:

Originally Posted by Mike_G

I don't know, I have set floats by the book 1,6mm up form carb body and when I pumping fuel into it everything is ok but when I start engine it starts to overfills. I don't see another problem in my carbs so I will try to put those pumps back in bussines and will see how it works

When you say it overfills where is the fuel coming from to make you think its overfilling the carbs?

Mike_G · 30-05-2007, 06:56 AM

Quote:

Originally Posted by scottyboy

When you say it overfills where is the fuel coming from to make you think its overfilling the carbs?

It comes from jet and stem (back to the picture part number 17 and 18) and once I saw it comes from air jet (number 16) I don't know why it cames from there.

Sorry for coming back to those pictures but I don't know technical english very well

Wacky Racer · 30-05-2007, 01:34 PM

Check part No 29 that it is shutting the fuel off, there should be a rubber tip on the needle, if its comming out of No 16 the bowls are overfilling.

Mike_G · 30-05-2007, 05:57 PM

Needle have got rubber on the top, I have checked couple times

Wacky Racer · 30-05-2007, 08:51 PM

Try removing the pump pins and replace with a nut & bolt and rubber washer,
That should do away with the accelerator pump side of things and try again. Sounds more like excessive pressure in the fuel line, should be around 5 lbs maximum, try a pressure reg.

marshan162 · 31-05-2007, 01:48 AM

Quote:

Originally Posted by Mike_G

Pressure is ok cause it's orginal pump I had rebuild so it can only have to low pressure I think.

I was holding carbs upside down while setting it up but I'm not exactly sure how should it be set??

How can I check reeds??

The problem is even when I don't start engine but only pumping fuel into it when it stands straight it is ok when I trimming it up it over files. I will try to set floats again tomorow. Maybe it will helps

Is this an electric pump? If it is, and it's been rebuilt has the pressure relief valve spring been replacd? If the wrong spring spring has been fitted the pressure could be too high

You need to check the pressure. Only then will you know if it is a carb problem or a pump problem. I think it is a pump problem, I cant see how all three carbs could fail together

Mike_G · 31-05-2007, 02:28 PM

One more question:

How to set idle mixture?? Part number 2A. I have got 1,75 turn. How do you guys have set it??

simon · 06-06-2007, 05:50 PM

Hi mate I had a similar problem with my xr2 on a number of occasions. Mine always seemed to cure the fault after a strip and clean. This may not be of much help but just a warning be careful whilst your trying to find the problem as I had a major engine fire due to this occuring. The vapours from the fuel in the lower tray went off with a bang and the fuel in the tray stayed alight.

Just remember Switch off that electric pump!!! if it does decide to go up, sounds obvious but easy forgotten in the heat of it, so to speak. Fuel keeps pumping out of the carbs even when the engine is not running if the pump is on. Mine kept re-igniting from the heat of the engine even after emptying a couple of fire extinguishers over it.

Hope you soon find the problem - maybe a damaged or destorted needle or a cracked seat. You may not see this with the naked eye so maybe worth replacing these anyway. Also could your exess fuel (choke) solenoid be seeping fuel through to the carbs???

simon · 06-06-2007, 05:53 PM

Hi mate I had a similar problem with my xr2 on a number of occasions. Mine always seemed to cure the fault after a strip and clean. This may not be of much help but just a warning be careful whilst your trying to find the problem as I had a major engine fire due to this occuring. The vapours from the fuel in the lower tray went off with a bang and the fuel in the tray stayed alight.

Just remember Switch off that electric pump!!! if it does decide to go up, sounds obvious but easy forgotten in the heat of it, so to speak. Fuel keeps pumping out of the carbs even when the engine is not running if the pump is on. Mine kept re-igniting from the heat of the engine even after emptying a couple of fire extinguishers over it.

Hope you soon find the problem - maybe a damaged or destorted needle or a cracked seat. You may not see this with the naked eye so maybe worth replacing these anyway. Also could your exess fuel (choke) solenoid be seeping fuel through to the carbs???

Mike_G · 06-06-2007, 09:27 PM

Quote:

Originally Posted by simon

This may not be of much help but just a warning be careful whilst your trying to find the problem as I had a major engine fire due to this occuring. The vapours from the fuel in the lower tray went off with a bang and the fuel in the tray stayed alight.

Had this one already

Fortunetly I have turn the electricity of

I don't have any more ideas what to do with those carburators. I thought that carbs are very simply.... but mayby I'm not smart enough to find out what is going on.

I have found a guy here in Warsaw who is fixing carbs for over 25 years.
He did carbs in my fathers car back in 1981 so maybe he will do something with it....
Gave him my carbs today and he said that friday/saturday they should be working.

Hope to run my boat in sunday. Cause I haven't run it since I bought it and rebuild it

Ok I did 3 or 4 60seconds test runs but always had problems with those carbs.

Mike_G · 06-06-2007, 09:36 PM

Another question
Do you know maybe what size of jets should I use??
Maybe someone changed jets in carbs and this is the problem??

Will this table help?? But I don't think that those sizes fits xr2

Burty · 06-06-2007, 09:41 PM

no dude, XR2's have lots of different jet sizes depending on which carbs they are

Mike_G · 06-06-2007, 09:46 PM

Quote:

Originally Posted by Burty

no dude, XR2's have lots of different jet sizes depending on which carbs they are

I thought so
Do you know where can I found proper sizes??

My carb looks like this:
http://www.mercruiserparts.com/Show_...RETOR+ASSEMBLY

Burty · 06-06-2007, 10:21 PM

Can't help you there mate, cheapest way is to read ya plugs but this aint easy. Easyist way is to get an EGT guage but this aint cheap

Mike_G · 07-06-2007, 03:07 PM

And what about solenoid?? If it isn't seeping fuel maybe it won't turning off somehow??

How does it work in this engine?? Temp sender is turning choke off when it's hot?? Maybe sender is broken ??

What do you guys think about it??

"Old beardy" · 07-06-2007, 06:24 PM

My carb looks like this:
http://www.mercruiserparts.com/Show_...RETOR+ASSEMBLY[/QUOTE]

We ran 68 main jet in those type of carbs, I think standard they should be 72, with 74`s as break-in jets.

simon · 07-06-2007, 07:13 PM

ur solenoid is like a straight forward on/off tap usually activated by pushing key switch in. To elliminate this just remove the tube between ur solenoid and ur carbs at the carb end and put a kink in the tube (cable tie off whist running), you may need to fire engine up first then disconnect tube.

Mike_G · 09-06-2007, 09:43 PM

Ok I have found my problem!!!!!

I'm an idiot, I have connected fuel pump wrong, effect was that it was pumping fuel but it was 20+ psi not 5 psi how it should be I have reconnect fuel pump and it works like rock and roll

Thanks guys for help!!!!!!!!!!!!!!!!

After all I have found good points from this situation. Except founding that I'm dumb ass I have learned alot about my carbs and put all new seals into it.
Boat runs great.

Will post some pics and gps numbers tomorow

One more question: What should be water pressure?? My gauge is telling me something like 10+psi when running at wot. Is it ok or should I buy new impellor?? Water is comming form the back even when running at idle so it should be ok but I want to be sure not to fry the engine