Another XR2 problem to deal with...

HT20 · 11-07-2010, 10:05 PM

Hi guys!

Got the boat on the water this weekend after a 3year-restauration process with the boat.

during this process i had to swap the 2.5EFi for a XR2 due to the funds involved with rebuilding the boat itself, so there was no money left for the rebuild of the 2.5EFi.

Now to the point, the XR2 engine i got is in good condition compression wise etc. but today it had a problem with it refusing to run flat out on the way back to port.

When getting back home to the shop I pulled the plugs and they were wet and black, couple of sylinders were totally drenced with fuel. top one on starboard and middle one on the port side I think it was.
Stuck carbs or what?

Ordered new plugs, gasket sets/repairsets/fuelfilter etc for the carb this evening and new standard jets. (.068)

Going to go through all carbs and clean them well and see what happens, also need to adjust the idle mixture some, as it bogs abit after running slow in and out of the port....
Anyone have any suggesions on what to look for other than this?
I`m not to familiar with the XR2 so I`m greatful for all help I can get.'
Have tried the search-function but came up short on this issue..If you know of any good threads, please link the on here for me to read...

Also I`m running a 14x26" Merc over hub cleaver, and a Turbo lightning 14 3/4" x 25 as of now, but I `could not get the engine to really push up to the 7000RPM mark, barely made it to 6000RPM`s..Is this normal with the XR2? I see the race guys over here used to run props with even bigger numbers than that...

The boat is a Hydrolift T20, highly modified...much lighter now due to all composite..no longer wood.

Thanks for any help!

Techteam · 12-07-2010, 01:07 PM

So without looking it up you sure you should be running 0.68 or is that a typo. Check the floats are closing on the carbs look down the venturi and check for leaks from the little brass slosh tube. If everything looks fine you sure you have good plugs in it and a good spark sounds like you may have a non existant or very weak spark.

HT20 · 12-07-2010, 03:31 PM

The .068 is what mercury lists as the run jet, Break in is .072/.075
Have orderd new plugs and repairsets for the carbs, should get here in a day or two.

What would you suggest jet wise? I havent found any diagrams over any other jets for the XR2 that will include different factors on what jet to run.

If you know of any it would help out a lot.

As for the spark, what to check here? Timing of course, but is there other things to keep in mind?
Since the engine revs up under load I suspect that the stator is ok, or can I be mistaken about this?

willwood6 · 12-07-2010, 04:27 PM

0.80 Jets in an XR2 according to my mercury manual!

0.44 Idle jets.

Wouldn't put .68's in. Have you checked your reeds for any damage, they could result in over fueling.

"Old beardy" · 12-07-2010, 06:04 PM

Quote:

Originally Posted by willwood6

0.80 Jets in an XR2 according to my mercury manual!

0.44 Idle jets.

Wouldn't put .68's in. Have you checked your reeds for any damage, they could result in over fueling.

Does it not depend on which carbs you are running? I know we used to run 0.68 on one of our older motors.

Techteam · 12-07-2010, 08:25 PM

Quote:

Originally Posted by "Old beardy"

Does it not depend on which carbs you are running? I know we used to run 0.68 on one of our older motors.

Yes some early ones got what I call the pumper carbs and some of the last engines got the non pumper adjustable idles but both were poor for power.

HT20 · 12-07-2010, 08:57 PM

I`m getting the parts tomorrow, going to go through reeds and everything when all the gaskets and such arrives.

The motor is produced late in 1995, if this give you any info on the subject of carbs.

Myself, I was not avear of the different carbs. The jets will probably give a pointer to what type they are-or maybe you could give me any pointers on what to look at?

Also I see alot of the Phantom/ring guys run low pitch propellers on their XR2`s.. 21, 22, 23 an such.

I`m thinkin this engine got it`s hands full with the 25 and 26`s I have put on it.
But that also seem strange to me, since I know of quite a few that have runned these types of propeller sizes with good results.

maz928 · 12-07-2010, 09:40 PM

The later carbs were baffled and had a pipe down each side of the carbs to stop flooding in rough with the pounding from the conditions.These ran 94 jets as run in and 90 jets as standard.More fuel more air and more power!!
These were the best carbs imho.

The reason people ran with large props(25/28) on the XR2 is down to them running a 2:1 gearbox and the ones running 21s etc are running 1.86 gear ratio boxes.

HT20 · 12-07-2010, 10:18 PM

Thanks for the reply.

Will post some pics when going through the stuff tomorrow. (If parts arrive)

If by tubes you mean the yellow ones, there are two of them going out from the top of the carb and out on each side...on all carbs.
But will know more tomorrow.

HT20 · 16-07-2010, 06:29 PM

Finally got to the shop today and started on the XR2, And I discovered that the main jets were .090... This seems abit big for a stock engine dosent it?

The carbs have this marking on them:
1374-54270 This is towards the engineblock.

And on the opposite side, the intake they have this marking: 46-32504.

Hopefully some of you will have som info for me..

I use the ishopmarine-catalog for ordering parts here in Norway, just to look up in...and both serialnumbers on the XR2 lists the .068 for RUN on the WMH-7 carb. And the .072 as run in the WHM-18A carb

Is the .080 listed as Run in the manual?

shepster · 16-07-2010, 07:25 PM

Hi yes the 0.80 is listed as normal running jet and 0.44 idle jets

These are for the twin float carbs.

HT20 · 16-07-2010, 08:10 PM

Hi.

Just realised this myself...I have been looking at the wrong engine type

HT20 · 23-07-2010, 02:56 PM

Ok, got the engine back togheter today, going to give it a test tomorrow.

The engine had the .090 main jets in it, and they also have changed the Idle air jets to .046 instead of the ones you guys have in your manuals listed to .044.

The engine has got the .080 in it now with the .046 idle air jets.

Have ordered the .044, but in the manual, the correct one as I later found out-since the first manual had the pumper-carbs listed...And I have the newer style carbs.

But to the point, this manual had the Idle air jets listed to .056.

But you guys have the .044 listed as the original ones?

A little bit confused

Techteam · 23-07-2010, 04:51 PM

So please don't run it with the 80's in !!!

You haven't given enough information for someone to comment. I suspect you have one of the later SST120 powerheads which some offshore guy's replaced their XR2 powerheads with when the supply of XR2's started to dry up. I suspect thats why you have 90's in which is the SST standard jet. I think that 80's WILL BE WAY TOO LEAN. I'm quite prepared to be proven wrong but are you prepared to chance your motor?

karl · 23-07-2010, 11:40 PM

dude i had the same probs with an xr2 that had bin messed with i got all the right jets but changed my power head , give cye a ring as he borrowed them to use on his xr2 see if he still got them they are the right ones cys xrs 2 went like **** wth them in

HT20 · 26-07-2010, 11:14 PM

Techteam, you are probably right this time..

Changed the jets to .080 today-took the boat out for a ride, and noticed straight away when getting on to plane that my exhaust-temp went way up-so I let her back down and idled back into port.

The exhaust went straight up to 1400Farenheit on my dual Livorsi with the .080 Jets.. Lacked quite abit of power too.
With the .090 Jets i was around 900Farenheit, max RPM was 6000 and the sylinders were flooded with petrol after this...

My 2.5EFi ran between 1100-1200Farenheit at WOT if my memory serves me right.

I have checked the compression now on all six, they are even around 135psi, I suspect they are abit higher to, my gauge leaked abit i suspect since some petrol made it out through the treads and onto the sidewalls on the heads...

The gauge had to much treads on the end of it-had to make a spacer with two O-rings on both side...this probably didnt seal enough-hence the petrol leak.

Going to have a go with .088/.086.

Reeds were really nice and sealed well, carbs have fitted all new Rep-kit to them and bowls are adjusted to 1.6mm below the gasket surface according to the manual.

Techteam · 26-07-2010, 11:28 PM

So I'm not going to say here what I consider the max to be on an accurate pyro but 1400 is way too high and close to disaster. So I agree that 088 is probably a good area to be in 086 probably starting to be borderline.

HT20 · 30-07-2010, 11:38 AM

Still waiting for the main jets to arrive...

Where do you guys find the .044 Idle air bleed jet in your manual?

In my partslist the Idle air bleed jet lists as a .056.

Would really like to have these carbs dialled in the next time I`m out testing..
Engine seems to run abit rich on idle with the .046 that is in there now.

One more question: bigger Idle air bleed jets=more air or more gas?

Bought both the .044 and the .056 that`s in the partsdiagram.

HT20 · 30-07-2010, 01:23 PM

Both the SSt 120 and the XR2 later version lists the .056 as the stock idle air bleed jet..

If the SST 120 has this as the stock idle air bleed, how can you guys run the .044 as a idle jet? Your motors must be running way to rich on idle?

HT20 · 07-08-2010, 07:15 PM

Just thought I would let you guys in on what that probably was the fault all along, or a big part of it.

Spoke to a guy over here about the engine, and he gave me a couple of pointers on what to look for.

First the ignition was set to high....

Then I checked my coils, two out of six had a cracks in the graphite core, apparently this will cause the ignition to cut/stop out att 5-6000RPMs..

Just thought I would let you guys know in case some of you have/or will run into a simular problem...

After all this forum is a place to learn more about these engines ain`t it?