62T in a Blaster revs only to 6600 hooked

Zero Client

Zero Client

BeerrroooOOOT!!!
Location
Douglasville, GA
The 62T came out of a 701 wave raider. Currently:

717cc (+1mm)
Riva ported 62T cylinder
ADA head running 165~170psi
Squish band .045" (The cyl is decked but I'm running a .040 base gasket)
Dual 38mm Carbs with ProK FAs
Protec pipe
Riva Purple CDI box (Advent? Adjustable rev limiter)
Dual cooling
Engine runs at 145F using the stick-on temp gauges
Waterbox is a rear-mounted Waveraider unit with a 2mm water inlet pissing into it after the stinger

Pump is stock, un-bored Raider unit with a Solas 13/17 prop

Carbs are jetted as follows:
.5 turn Lows
72.5 Pilots
1.5ns
80g Springs
130~137.5 High jets
Various high screw settings


So, I can't get the engine to rev while hooked up past 6600rpm. If the pump unhooks, or if I trailer test it; the engine will reach 8000+ with the rev limiter set to the highest setting on the CDI. I am tuning for max RPM using a tiny-tach.

Theres no added speed past 3/4 throttle. After 3/4, the engine speed and velocity feels exactly the same. While trying/testing, I tried a smaller main jet (130) in each carb but that did not change anything at all. I also tried lifting the hood while at WOT to see if the RPM increases at all -and it does not.

Any thoughts?
 
Zero Client

Zero Client

BeerrroooOOOT!!!
Location
Douglasville, GA
Maybe too much water. I took the Protec's stinger off, and noticed at the very end of the head-pipe theres a water injection inlet into the pipe. Not unlike a B-Pipe but similar concept - only the Protec pipe has no way to adjust the flow stock, and the fact that there is only 1 water-jet instead of 3x on a B-Pipe's headpiece. The inlet/water injection diameter is 2.5mm wide!!! When blowing through by mouth it bleeds so fast its like FREAKY FAST (Jimmy Johns reference).

This prompted me to get the small drill out, and drill/tap that injection inlet to 4mm - the same thread and pitch as a Mikuni SBN carb pilot jet. I put a spare 67.5 Pilot jet in there and I'm sure its going to flow much less water that way. Its actually much harder to 'blow' through the headpiece now.

I'll put it back together like that and get it on the lake. Maybe this time the expansion pipe will get over 150 degrees and MELT some couplers while pulling 7500RPM!


/me starting to hate Protec pipe
 
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Quinc

Quinc

Buy a Superjet
Location
California
Run a inline water filter. Also check with protec on what rpm range the pipe makes its peak power. For instance a bpipe makes its peak power at 6700rpms.
 
Zero Client

Zero Client

BeerrroooOOOT!!!
Location
Douglasville, GA
So with putting a 95 pilot jet (67.5 was increased to a 95 for the first test) into the pipe's water injection, the RPM has now come up by about ~250 rpm and now hits about 6850. The external temperature on the pipe has also gone from about 135F to about 175F. SO limiting the water injection helped a bit with RPM. Jetting is still in-accurate up top as a 130 and a 137.5 didn't make much of a difference at all. So, I'm gonna go back on the water with a 75 pilot jet in the exhaust to see if I yet again gain another couple hundred rpm, and then main jet tune from there.

Thanks!
 
catpower

catpower

Location
iowa
I have the Mach 2 pipe. The hole your describing in head pipe is non-adjustable correct? Intended to cool coupler. I plugged mine with JB weld and opened up nearest water screw 1/4-1/2 turn. My expansion chamber runs if I remember correctly 140-160. I know for sure my head runs at 140 deg with water restrictions on each cylinder outlet on head. Using FDA approved temp stickers. I ran it this way all summer with no coupler heating problems. I don't have a tach on it but it performs very well in a short time once pipe gets up to temp. Stock prop and I think I need a mag or a prop to load motor a bit more. Seems to spin prop too easy on throttle stab.very good top end.
 
catpower

catpower

Location
iowa
I read post again not for sure if your running a ewic. I have one on mine and drilled , taped spray bar inserted into mani with main jet style threads and running 60 or 90 main. I'd have to pull out to check. I'm thinking protect calls for a 60.
 
Zero Client

Zero Client

BeerrroooOOOT!!!
Location
Douglasville, GA
I'd love to know your actually peak RPM figures.

I don't know exactly which Protec pipe I have, except its one for a WaveRaider. The stinger points straight back and connects to a WR waterbox in the rear.

My protec pipe has no adjustments except the one I made before the coupler - it only seems to have 1x water jet just before the coupler.

I definitely don't have an EWIC.
 
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Quinc

Quinc

Buy a Superjet
Location
California
Zero Client said:
I'd love to know your actually peak RPM figures.

I don't know exactly which Protec pipe I have, except its one for a WaveRaider. The stinger points straight back and connects to a WR waterbox in the rear.

My protec pipe has no adjustments except the one I made before the coupler - it only seems to have 1x water jet just before the coupler.

I definitely don't have an EWIC.
Click to expand...

Call Protec and talk to Carl.
 
Zero Client

Zero Client

BeerrroooOOOT!!!
Location
Douglasville, GA
with the 75 pilot jet, the pipe gets pretty hot. Im going to increase to an 85 pilot jet in the pipe.

My RPMs are hitting about 6900.... so, I'm starting down the road of getting dual OEM 44s set up in this ski. Its going to take about a month but maybe it'll give me better top-end.
 
Zero Client

Zero Client

BeerrroooOOOT!!!
Location
Douglasville, GA
so, I got a set off OEM Mikuni/Yamaha sbn44 carbs out of a GP760. I built them up and tuned the things as follows.

2 turns low screws (These are fine threadded screws)
122.5 Pilot jet (Tried 127.5 and 125 and it was too rich after 1/8 throttle)
2.0NS
65g spring (Tried 95 then 80 and it was too lean off-idle)
Tried 115 and 125 main jet (Not much difference)
High screws closed. Opening them changes nothing.

This setup feels fantastic down low. Honestly I feel the dual 44s are hitting harder than the dual 38s were which is a really good benefit and hard to get right with 44s.

I then found an intake/air hose coming from the WB1 hood was crushing against the gas tank likely slowing airflow so I clipped the hose off the hood. The engine seems to breath better now but its still not perfect. The ski feels better but still doesn't seem to be performing as well as the WB1 next to me. I just don't seem to have the top-end like the piped stock bore/non-ported 61x 701 WB1 next to mine at the lake.
 
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holeshot

holeshot

HPE products
Location
ca
Check to be sure your running a matching cdi and stator. as in 61x cdi and 61x stator or 62t with 62t. also i would run 117.5 low, 122.5 main, 1.5 n/s with 65g spring. check your reeds too.
 
kdog701

kdog701

Location
Georgia
Mine is doing that to ..not sure what's up ...tuned my pipe hot as hell and all...gonna tweak carbs a little more this spring and c


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