My 61x/61x is a dog compared to 61x/62T

[Mechzxeng]

So heres the story I have 2 skis:

1991 SN 61x/61x with wetjet intake, wetjet pipe, propped with a Skat track straight blade SlimLine 10/15 (Custom pitched by impros) this impeller was setup for the 650 that used to be in the SN which made a huge difference on the 650. After I dropped in the 701 I noticed more pull but not as much as I expected.

Also run

1999 RN 61x/62T, mild exhaust porting, ADA head 35cc domes, Riva red full exhaust, and a 2008 OEM prop (similar to hooker 9/15) - this thing is a beast compared to the SN.


My question for all - is the impeller the main thing holding the old SN back? Obviously the RN has extra work done to it but I could have sworn when I had the RN near stock (pipe and 14/18 solas straight blade) it had notably more jam then the current SN setup.


I might try swapping the pumps and test the theory on this one before I shell out to upgrade the impeller.

Thoughts?

 

[Roseand]

You have better cases and carbs, higher compression, porting, a better pipe, and a better prop. Of course it's going to absolutely stomp over your SN.

Sent from my SM-G920V using Tapatalk

 

[Mechzxeng]

You have better cases and carbs, higher compression, porting, a better pipe, and a better prop. Of course it's going to absolutely stomp over your SN.

Sent from my SM-G920V using Tapatalk

This Im not denying. To the orginal question "My question for all - is the impeller the main thing holding the old SN back? Obviously the RN has extra work done to it but I could have sworn when I had the RN near stock (pipe and 14/18 solas straight blade) it had notably more jam then the current SN setup."

The 61x/61x does have 46mm carb which should compete with the dual 38s, yes better case flow tho.

My main concern is that the impeller is drastically limiting the 61x/61x ... I dont expect it to compete with the RN.

 

[Captain PegLeg]

Id have to say that wetjet pipe is a big set back. Yes, its a improvement over stock, but its made for the general public in a sit down couch. It wont offer near the performance as a pipe designed for a superjet.

 

[Scribbleheli]

I was under the impression that the wetjet pipe was like a big heavy cast B-pipe? Similar power, just extra weight?

 

[Mechzxeng]

Hmmm, found this link. You might be right.. I thought that low of pitch/quality prop the 701 should nearly cavitate.

I did find this hidden link on cooling the wetjet pipe - I may be pumping to much water into the upper water injections ports on the pipe. Gonna buy some restrictors and see how much I can dry it out.

http://www.x-h2o.com/index.php?threads/water-injection-for-pipe.149813/

 

[Quinc]

The wetjet pipe is a turd. Dry it out or upgrade to any other pipe. If you think the impeller is the issue try switching impellers with your RN.

 

[Mechzxeng]

Right now Im running this setup - which dumps the majority of the water into the pipe. The small water outlet on the front part of the head is dumping direct to the pisse

The wetjet pipe is a turd. Dry it out or upgrade to any other pipe. If you think the impeller is the issue try switching impellers with your RN.

Im thinking this winter may have to upgrade. In the mean time Ill try drying it out. correct me if Im wrong the only risk in drying out the pipe is melting the rubber grommets connected to the water box and perhaps the shear risk of a hot pipe in an enclosed hull? OR are there other concerns with the pipe running hot?

Anyone want a gently used wetjet pipe....

 

[Quinc]

Before you do anything hook up the water line going into the manifold to your garden hose and see exactly what it is doing. You want to limit the spray going into the chamber as much as possible until you get the chamber around 180ish. Start there and then adjust the temp of the chamber up or down by 10-20 degrees until you get performance how you want it. Search out and read the water tuning a bpipe thread to get an idea of what you are looking for.

 

[Jet_jase]

I used to run a fully ported 760 62T/61X in my Evo and that let go so grabbed hold of a friends ported 701 61x/61x and if im honest i like the 61x motor more. It seems to be more punchy at the bottom.
I now have a 5mm ADR crank in it so 810cc with 48 Novi and thats even better with loads of mid range torque for surf with pretty much the same fuel usage.

I also like that fact i have only 1 carb to worry about with easier access to everything around the engine without pulling the airbox off.

I'm not saying 62T isn't better with bigger CC's but lower down cc's and tuned properly there isn't much in it.

 

[Mechzxeng]

I will try drying it out some. If that does not work Ill swap props.

Thanks Quinc. I Read the thread on tuning b pipe - not sure I want to take it off and hook it up to the garden hose unless necessary at this point. Ill start hotter and add coolant as necessary.


Any risks with a hot pipe? Melted grommet being the main one?

 

[Quinc]

I will try drying it out some. If that does not work Ill swap props.

Thanks Quinc. I Read the thread on tuning b pipe - not sure I want to take it off and hook it up to the garden hose unless necessary at this point. Ill start hotter and add coolant as necessary.


Any risks with a hot pipe? Melted grommet being the main one?

Keep it under 200 and you will be fine. I have ran my bpipe as hot as 212 and nothing melted.

 

[long beach local]

I used to run a fully ported 760 62T/61X in my Evo and that let go so grabbed hold of a friends ported 701 61x/61x and if im honest i like the 61x motor more. It seems to be more punchy at the bottom.
I now have a 5mm ADR crank in it so 810cc with 48 Novi and thats even better with loads of mid range torque for surf with pretty much the same fuel usage.

I also like that fact i have only 1 carb to worry about with easier access to everything around the engine without pulling the airbox off.

I'm not saying 62T isn't better with bigger CC's but lower down cc's and tuned properly there isn't much in it.

I have 2 identically port matched 61x cylinders , 1 is on a 62t cases w/38 carbs and the other on 61x cases with 1 44carb . The 62t has more on top but I prefer the 61x in my SF badass for riding surf . The bottom end is snappier and also midrange fuel range is the same.

 

[Jet_jase]

I have 2 identically port matched 61x cylinders , 1 is on a 62t cases w/38 carbs and the other on 61x cases with 1 44carb . The 62t has more on top but I prefer the 61x in my SF badass for riding surf . The bottom end is snappier and also midrange fuel range is the same.

All my ride crew love the 61x motor for this reason, we all ride them. Maybe the 62T with 44mm carbs will piss all over a 61x but the your fuel usage will be a lot greater. Just open the throttle earlier to go higher

 

[augustaf]

I had SN skis with 62T/ big bore, dual 46's, Fac. Pipe. These setups did reasonably well. Eventually changed over to RN's = huge difference with same engines. Suppose the larger diameter exhaust had something to do with that.

 

[kevbo]

This Im not denying. To the orginal question "My question for all - is the impeller the main thing holding the old SN back? Obviously the RN has extra work done to it but I could have sworn when I had the RN near stock (pipe and 14/18 solas straight blade) it had notably more jam then the current SN setup."

The 61x/61x does have 46mm carb which should compete with the dual 38s, yes better case flow tho.

My main concern is that the impeller is drastically limiting the 61x/61x ... I dont expect it to compete with the RN.

It is very likely that your impeller is too flat for a low port 701. Swap pumps and see what happens.

 

[Mechzxeng]

Update:

Prop made a difference very small tho.

Drying out the pipe helped considerably. Ended up needing to add a second pisser to dry it out enough.

Still not perfect or as hot as I'd like it. Gonna add a water filter and dry it out further next weekend... I'll post the final setup once I have it dial in.


Promising results so far!

 

[tntsuperjet]

Advance the timing a little with that wet jet pipe, or put a little more compression in it.
I have an and round nose and notice nothing between them. Both have similar power plants and if anything the SN is a bit quicker
62t cases 6mm stroker duel 46's, 62t Cyl at 83mm bore.
There no noticeable fuel consumption over similar setup with 38's
On most rides they have less then a 1/2 inch more fuel at the end of a long ride that is below what would be reserve level in the ranks.
Some days I even use less fuel then they do.
All depends on how clean your jetting is.
Now with a set of full specs or novi carbs fuel consumption goes way up.