Thread: Ultra 250 Piston Kit
12-19-2008, 11:02 PM #1
Ultra 250 Piston Kit
JE Piston Kit
Saturday, August 23rd, 2008
WARNING, the following entry is NOT instruction for instillation. It is simply a review of what I did to install my own pistons on my own craft. Doing this instillation without knowledge of this motor could cause severe damage and costly repairs. DO NOT ATTEMPT TO USE THIS REVIEW AS A GUIDELINE OR STEP BY STEP INSTRUCTION. YOU SHOULD ASSUME THAT I DO NOT KNOW WHAT I’M DOING.
JE piston Kit
One can buy them at R&D Performance or Macc Racing.
Lets get into this kit.
I cant possibly go into the complete installation but Ill cover alot of the important stuff for you. Get a Service Manual if your going to do this for the first time. TRUST ME GET ONE.
First I took an inventory of item that are needed to do this job and the extra parts to support the piston kit.
1 Of coarse the set of new 9.5 to 1 pistons
2 Pink injectors from R&D
3 Fuel regulator, R&D or Aeromotive #13105
4 Fuel return line for the regulator to dump pressure released gas back into the tank.
5 Fuel Pump Walbro 255 lph HP-GSS-342 or get one from R&D its your choice. This fuel pump is highly recommended but I have seen this job done without it and didn’t seem to have caused any issues.
6 Powershot is optional but also a helpful tuning tool to fine tuning the fuel or AFR.
7 Replacement gaskets. Don’t skimp on this one. You’ll regret it.
Here are the gasket numbers 11061-3708, 11601-3742, 11601-3760, 11601-3762 and 11004-3722 at a total $180.07
I opted to install a set of 09 260X cams into my 08 engine, they are what comes in the new 09. Trust me on that. The part number for them is 49118-3709 & 49118-3710 also needed is 13061-1687, 21007-3742, 92043-1575, 92150-1645
Now lets start by first draining your oil out of the motor and then pulling it out of the hull. Go by the service manual starting on page 7-2, though I did mine a bit different then the manual. I started by removing the Inter cooler, exhaust, SC and intake manifold inside the boat. Once I had that done I went on to remove water lines, marking them as I went. Once those were off I remove all sensor plugs to the block and lifted it up just enough to get the two front engine mounts off to avoid scratching the paint.
Once you have the motor out you will find that you have enough item off the motor to start with the tear down to the pistons only. Notice I left the oil cooler and oil filter in place.
Starting in 6-2 of your service manual you’ll find the steps in getting to the pistons.
Removing the head off the cylinder is not that hard. First remove the tensioner on the side of the motor.
Then the cam cradle.
Do not take the valves apart. Be careful when removing the head as to not disturb or loose the buckets and shims. Leave them just as they are. If you do jolt the head you could upset the buckets and cause the shim to become unseated thus making the bucket sit higher then normal. This picture below shows that the intake buckets are not seated correctly on cylinder number two. Look closely to it in correlation to the others.
This is the shim I’m speaking of. It sits under the shiny buckets.
Well the manual covers the steps in getting to and installing the pistons. Pretty cut and dry. First remove the chain tensioner.
Then the rotor cover to get to the bolts holding the chain guides.
Once the chain and guides are removed then gently pull up on the cylinder making sure to stay even when pulling up.
Removing the pistons from the rods should be easy enough.
Lets get into putting this monster back together.
First thing is to ensure you have installed the new pistons on correctly. The stock pistons are marked with a dot for the exhaust side but the JE ones are not. This is simple though. Find the side that has a 17.5 mm gap and thats the exhaust side.
Once you have your pistons on the rods with pins and all its time to figure out the ring placement.
The following pic is of the rings on the pistons, also covered on page 6-35.
A= Top Ring
B= Second Ring
C= Oil Ring Steel Rails
D= Oil Ring Expander
Yellow Circle red dot is the exhaust side marking.
From the manual, The piston ring opening must be positioned as shown in the figure. The opening of the oil ring steel rails must be about 30 to 40 deg angle from the opening of the top ring.
Make sense? Good!
Moving on, next comes the base gasket and piston installed into the cylinders. Two methods of doing this. First is the by hand method and it does work well with the JE pistons but not so well with stock pistons.
You can also use the fancy tools the manual shows,,, the tools
Them on the pistons collapsing the rings.
Them together after we had 2&3 in…
Slapping the cylinder down over the pistons.
And finally on. Next time I’m trying only the hand method. Notice below the 17.5mm side of the piston is facing the exhaust side of the block.
Don’t forget to get the timing chain and fish it up through the cylinder. Now its time to tighten down the head. Follow the picture below in the bolt pattern, first tightening is going to be followed by numbers to 17ft-lb then followed again in the same pattern to 44ft-lbs.
Now install the head and the cams with chain over the cam wheels. Its important to get the alignment perfect.
Fist be sure you have top dead center and the easy way is this picture.
Wait T1.4 is NOT 1 of 4 at Top its was suppose to say T1.4 is 1 & 4 TDC. Sorry about that.
Still once you have that set up correct its now time to set your cams in the head with chain over it. Get you cam position by the following pic. COUNT YOUR LINKS!!!!!!
Once you have the cam cover on and the cams and TDC set correctly its time to set the cam chain tensioner. Be sure when that is set that nothing moved. Recheck this before tightening down the cam guide. Chain should look like this one.
Its now that you want to follow a tightening pattern again for the cam cover to 104in-lb
10 and 14 “pink” are longer silver bolts that go into the slots with a triangle marker on them.
At this point you should cover the engine before you attempt to reinstall it into the hull.
Once this is done then you can safely drop the motor back into the hull and reconnect all other components. Be sure to clean the surfaces of the exhaust system really good before installing NEW gasket to avoid water leaks.
Engine in? Connect everything back to normal? Good now go pull the pump or wait, its up to you. We can come back to the fuel system stuff later.
What Ive found is that adding the pistons gave too much power that the stock prop couldn’t hold it. It basically spun the prop too easily.
So I found that bending the tail edge of the prop help with bringing too high of RPM’s down and better hook up off the turns.
Here a pic of the pump out.
Here is a pic of the direction to turn to remove or install the prop onto shaft.
This pic is of a tool I made to bend the prop without too much damage. Notice the rounded edges of the wrench.
Used a grinder to get a rounded edge.
Now before you go bending away I must warn you that this ain’t easy and these guages are not so accurate. They are simply a reference point to bend off of. Also understand that when it come to prop bending that I’m really far off from knowing what I’m doing so proceed with caution or be prepared to bail out and sent it to Impros.com. Be sure to tell Dave to bend it to Skip’s piston spec.
If you have no fear then follow me into Prop Butchering 101.
First mark your prop and find beginning of the “leading edge = Red Arrow” and “tail edge = Blue Arrow”.
Notice how I marked the blades A,B,C, this is so I know what I bent and didn’t bend. Always use the same pattern.
Bend A first then when done move to B. Don’t skip a blade. Front edge extends from leading tip “Blue” to about half way down the blade and the same goes for the tail end. “RED”
Bend the tailing end down 1MM or about a half a degree. Be sure to level or feather out the bending. Use the guage to monitor or calibrate your bending and keep track of the stock setting verses how much your bending.
Got it? NO!? well send it to Dave then. Mine have all ended up there anyways. lol….
Lets role right into the fuel pump I chose to install. I used the HP fuel pump and bought mine from R&D cause I’m lazy and they had the right one in stock. Though they are commonly found at many on line Auto Parts stores.
Still Lets do some catching up on the stock fuel pump removal. Read this whole thing then return to get into the pump part.
OK so you’ve gotten the pump out. I’m going to show a bunch of pics with quick notes to them. Its pretty cut and dry work.
The new fuel pump and the R&D pressure block off.
Stock Fuel pump out and I’m going after the pressure regulator to install the block off.
Got it out.
Pulling it apart.
The R&D Pressure Block off next to the stock unit.
Putting it back together.
Installing the new pump requires you to stretch out the opening and drill out the screw holes to allow the bigger fuel pump.
New fuel pump wired in with heat shrink connections.
And finally the pump installed. Walla now that wasn’t hard at all.
Next is the pink injectors and the fuel controller with the powershot.
Break time. More coming on this one.
12-22-2008, 09:54 AM #2
07-14-2009, 01:49 PM #3
Ultra 260X Conversion kit
Sound like something I need, I'm ok with the bolt-ons, is there any one in Central Florida that you would recommend for installation of this kit. I live in St. Cloud just South of Orlando.
07-14-2009, 02:14 PM #4
email Skip. He's not on this site too much. He's in Florida somewhere's! I'm positive he can install the pistons, and cams! Wont be cheap, and race fuel is a must..
07-14-2009, 02:18 PM #5
Thanks for the info, I just e-mailed him, did'nt know I had to use race fuel, thought super would do it, Thanks again
07-14-2009, 02:20 PM #6
07-14-2009, 02:24 PM #7
07-14-2009, 02:28 PM #8
07-14-2009, 02:46 PM #9
got questions on compression and $ , call me when you have time, 321-624-6008
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