Make up a manometer, check the ski, start with the smallest hole possible that shows you no movement. You may not need as big as you think. That way as Jr. said you're still protected from water ingestion, the other nightmare.To be honest its still sucking down quite a bit when I blip it, not as bad as before however. I may have to add a hole on the back of the hood with a frog skin. I am thinking the 3.5 circle right in the center between my hood straps. That would let me add a second 2.25 drop tube in the future and still flow enough through the hood holes.
Any ideas are welcome of course.
Super Jet Project Dance-floor
- Thread starter Req
- Start date
How do I account for the added airflow I will need when I upgrade my motor? Manometer it to the size my current engine needs and add a half inch to the diameter maybe?
Oh boy, good question. From what I’m gathering and this is very vague, (assuming you have rickter type pole)add a couple of 2” up to the 900’s, after that from what I’m reading (1000’s and up) you’d probably need like 4 2”. My reasoning on my hood in addition to the fact the holes were there, a 2”=50.8 mm, that x2 + pole breathers would be enough for dual 48’s. From my test, I definitely needed the hood breathers. Looks like your running Dual 38’s I would bet 2 2” would cover future motor as long as you’re not going mega motor(1000+). Whatever you do check it.
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I beveled the inner edge of that hood mod I just did to get a marginal amount more airflow for now. Eventual goal is a 760 based, total loss, ported cases and cylinders, possibly bigger if a decent deal on something comes down the pipe. I just have one breather tube in the pole and one in the hood for now. I am betting I need to drop a second tube in the liner but I will see what the test reveals.
I got her to the lake but it was a short trip. Somehow my exhaust manifold is totally clogged and I don't have any water passing through my exhaust. Engine is moving water just fine. Thank God for independent cooling so I saw the issue right away and know exactly where the problem is. She was running sort of crappy but I think that was due to the clog but could be the temp sensor being funny. It was supposed to be clipped and isolated but it sure does not want to rev out.
Seat-of-the-pants feel with the 45 seconds of run time I have on her is amazing. The pole felt like it was in the perfect place, the tray is nice and comfortable, and it is very predictable.
Seat-of-the-pants feel with the 45 seconds of run time I have on her is amazing. The pole felt like it was in the perfect place, the tray is nice and comfortable, and it is very predictable.
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I am certain at this point I need a ton more airflow. This is going to involve cutting more airflow in the outer hood section as well as dropping an additional tube or larger tube through the liner.
Does anyone have any experience with a 3" drop tube? My math was showing that its over twice the airflow of the 2" tubes. It seems like it would be easier to locate one 3" down tube between the engine and tank than a couple of 2" ones.
Something like this. https://www.amazon.com/Gibbon-15110..."+vacuum+hose&qid=1563811360&s=gateway&sr=8-2
Does anyone have any experience with a 3" drop tube? My math was showing that its over twice the airflow of the 2" tubes. It seems like it would be easier to locate one 3" down tube between the engine and tank than a couple of 2" ones.
Something like this. https://www.amazon.com/Gibbon-15110..."+vacuum+hose&qid=1563811360&s=gateway&sr=8-2
Here is my plan for the airflow dilemma. I am going to run two frog skins on the outside of the flat section of the back of the hood. I am going to run them vertically, the airflow should be more than adequate for any engine I drop in here. Additionally Im not sure yet if I am going to run two 2.25 drop tubes or a single 3" drop tube. Im still waiting on feedback before I decide on that.
Any feedback is welcome on this front. Im sort of digging this idea but I am open to suggestions.
Any feedback is welcome on this front. Im sort of digging this idea but I am open to suggestions.
I chased down the clog last night. It was a clog in the hose going to the upper manifold. I used an old hose that looked in good shape and it had a restrictor and a clog in it. Super stupid and could have been really bad if I wasn't paying attention to my pissers. I also removed the restrictors in the head outlets as the head was running about 25 degrees hot.
I still dont know what the upper rpm bog is. I am torn between thinking its a carb issue and thinking its the temp sensor grounding out.
I still dont know what the upper rpm bog is. I am torn between thinking its a carb issue and thinking its the temp sensor grounding out.
I think I have tracked down the bog I was dealing with. I rinsed out the engine bay thoroughly on sunday and when I looked in the bay yesterday I had a little bit of gas on the bottom. It appears to be leaking from the rear carb. I am tempted to steal the freshly rebuilt carbs off my venture and swap jets to get me back on the water.
On to engine build planning.... The engine in the ski right now is just a engine to get me on the water. I will be shortly starting a port job on a 61x cylinder I have and blowing the bore out to 83mm. This is a stepping stone to improve my skills for a fully ported cylinder and cases motor I will do over the winter. My original intention was always to use a 62t set of cases but for some reason I cant stop thinking about a large single carb setup on a set of X cases. I have a set of x cases with a good crank and seals ready to rock if I want.
Just thinking out loud. More to come.
On to engine build planning.... The engine in the ski right now is just a engine to get me on the water. I will be shortly starting a port job on a 61x cylinder I have and blowing the bore out to 83mm. This is a stepping stone to improve my skills for a fully ported cylinder and cases motor I will do over the winter. My original intention was always to use a 62t set of cases but for some reason I cant stop thinking about a large single carb setup on a set of X cases. I have a set of x cases with a good crank and seals ready to rock if I want.
Just thinking out loud. More to come.
Quinc
Buy a Superjet
- Location
- California
Go with the 62T cases. If you go 61x you are going to want to get a wetjet Kraze 61x intake manifold, but it will cost you more then a set of 62t cases. And you can always run singe carb on the 62t. Post a pic of how you have the 38's plumed.
Funny, I can get my hands on a Kraze intake I think.
I have them plumbed the same way they were plumbed last year. Fuel feed to the rear carb, return out rear carb to inlet of front carb, return out front carb to gas tank return. Its really hard to get a picture of but it is plumbed just like my venture is.
I have them plumbed the same way they were plumbed last year. Fuel feed to the rear carb, return out rear carb to inlet of front carb, return out front carb to gas tank return. Its really hard to get a picture of but it is plumbed just like my venture is.
I think my local jet ski guy has a kraze sitting without purpose. I may try to work a deal to help him part it out if I can have the intake. The kraze was weird though, it sometimes had the head sometimes did not, did the same go for the intake? Toward the end they seem like they were just slapping whatever they had together.
I am aware twin carbs have more headroom but something is to be said about simplicity.
I am aware twin carbs have more headroom but something is to be said about simplicity.
- Location
- Cumming, Georgia
Funny that this came up. My RN came with a wet jet 61x motor with their intake and 46 SBN. I’ll be rebuilding it this winter and I’m not sure what direction to go with it. I wonder what the performance difference is between dual 38s and a single 46 is on a ported 701. Half the cost and half the hassle is nice on a 61x but does a 62t dual 38 perform that much better?
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I have been chasing some carburetor Gremlins but I've at least got a bit of Tray time. The hull handles really nice, definitely feels good at low speed.
additionally I made a decision on the motor I am building to put into this Hull. Currently I have a 62 t / 62t with a set of 38s, that was just to get the hull wet. I decided to go the WetJet 61x route. I will be boring the cylinder this week to 83 and maybe doing some mild porting. I'm going to assemble it on the vxr cases and crank that I have sitting on a shelf.
a few questions about the wet jet set up. Firstly it has the stainless steel reeds and I already lost a motor do to ss reeds. Am I overreacting or should I get some aftermarket reeds? Also I believe the jetting should be 117.5 152.5 if my reading comprehension is adequate. Is that a decent starting point? Seems close to a lot of people run in the carb settings thread. Also will removing the choke plate affect my jetting in any tangible way? Lastly does it share the same Reed petals with the base 61 x platform?
Thanks for all the help.
It looks a lot different than a regular 61 x setup that's for sure
additionally I made a decision on the motor I am building to put into this Hull. Currently I have a 62 t / 62t with a set of 38s, that was just to get the hull wet. I decided to go the WetJet 61x route. I will be boring the cylinder this week to 83 and maybe doing some mild porting. I'm going to assemble it on the vxr cases and crank that I have sitting on a shelf.
a few questions about the wet jet set up. Firstly it has the stainless steel reeds and I already lost a motor do to ss reeds. Am I overreacting or should I get some aftermarket reeds? Also I believe the jetting should be 117.5 152.5 if my reading comprehension is adequate. Is that a decent starting point? Seems close to a lot of people run in the carb settings thread. Also will removing the choke plate affect my jetting in any tangible way? Lastly does it share the same Reed petals with the base 61 x platform?
Thanks for all the help.
It looks a lot different than a regular 61 x setup that's for sure
I'll offer some opinion, for what it's worth.
1. my (admittedly limited) experience is that the choke will not affect jettting, but the flame arrestor will. It's a shame that all of the jetting info out there usually people don't bother to mention even if they're using stock vs aftermarket pods. I got an unexpected lesson on this one time when I accidentally left the 90 deg elbow off of a stock flame arrestor and had a very noticeable lean hesitation, put it back on and ran great. I was amazed that it could make that much of a difference.
2. I wouldn't run stainless steel reeds purely due to peace of mind. I have no idea if there is a real performance bennefit, but they scare me.
3. I'm pretty sure the wet jet uses the same reeds and cages, I have a friend who recently switched stock 61x to a wet jet intake and he used the stock reeds and cages.
1. my (admittedly limited) experience is that the choke will not affect jettting, but the flame arrestor will. It's a shame that all of the jetting info out there usually people don't bother to mention even if they're using stock vs aftermarket pods. I got an unexpected lesson on this one time when I accidentally left the 90 deg elbow off of a stock flame arrestor and had a very noticeable lean hesitation, put it back on and ran great. I was amazed that it could make that much of a difference.
2. I wouldn't run stainless steel reeds purely due to peace of mind. I have no idea if there is a real performance bennefit, but they scare me.
3. I'm pretty sure the wet jet uses the same reeds and cages, I have a friend who recently switched stock 61x to a wet jet intake and he used the stock reeds and cages.