Magoos 85mm + Single Carb. Anyone?

[Yamah0]

I have the Magoos freestyle ported 85mm flat top cylinders with a single carb, but till now i havent got my setup to run right and dont know what this setup is capable of ecxept what iv heard from u guys:frown:

When i first put the motor together, Paul had by mistake sent me the wrong size domes (28cc) so my compression was at 150psi and the ski did not feel powerfull at all for what its got, so i thought its ok its just cuz of the low compression.

So then Paul sent me 24cc domes which i got yesterday, and i put them on and that bumped my compression up to 225PSI:bigeyes: so i put some good gas and took her down for few minutes hoping that the low power issue was due to low compression but, Nope... the difference wasnt all that great, it was just a tiny bit better... i think.
I know 225psi is way high, but today im gonna swap these domes out with some 25.5cc and that should bring my compression down to 185 to 190.

Now Paul recommends running duals on his cylinders, which i havent got around doing yet cuz i wanted to try out the single, which gets me thinking now could the single carb be the factor limiting the power and unleashing the beast? So is anyone here with magoos cylinders like mine running a single carb? If so what size and how do u like it?

Today im gonna take off the 44mm ATP carb i have on, and put on a
49mm Full Spectrum and see if itll make any difference. If so then its hopefully carb issue

Anyways thanx in advance.

 

[Mile9c1]

Where do you have the waterscrews on your pipe set at? I'd only open the top one, try 0.5 turns out to start with.

Were you trying a stock 44mm carb? What jetting? You'd be a lot better off with duals, but it should run well with a single.

 

[sflsurfrider]

whats your jetting and popoff at?

 

[Big Kahuna]

That ski should be ripping with a single, even if it a stock single 44.......


Check your adjustment screws on your pipe............ Also, 4cc's is not going to net you 75 lbs more compression, sounds like you had a leak in your head........... with ADA 701 domes 38cc will get you about 170 lbs +/- and 35cc will net about 185 lbs +/-...........

 

[Yamah0]

Where do you have the waterscrews on your pipe set at? I'd only open the top one, try 0.5 turns out to start with.

Were you trying a stock 44mm carb? What jetting? You'd be a lot better off with duals, but it should run well with a single.

Well i messed alot with the water screw and i dont really remember where i left them at but i think top and middle are closed and the bottom is open quarter turn... ill check tomorrow.

I was running the ATP carb, which is a modified 44 that opes up top to a
47mm.

Anyways i swapped out the carb today and put the 49 FS and it seems like the ski is ripping now or at least i feel its potential. Havent got it tuned right yet.

I ran 135 high, 125 Low, 2.0 needle/seat with a 115g spring and the ski didnt want to go, it was lean even tho i opened over two turns on the low, soo i changed the low jet to a 132.5 and the ski was ripping but not so clean and felt a lil rich.

Tomorrow im hopefully gonna try to find a 2.3 needle/seat and put the 125 low back on and see what happens.

I have not checked my popoff so i dont know. Ill check it tomorrow.
Where should it be at?

That ski should be ripping with a single, even if it a stock single 44.......


Check your adjustment screws on your pipe............ Also, 4cc's is not going to net you 75 lbs more compression, sounds like you had a leak in your head........... with ADA 701 domes 38cc will get you about 170 lbs +/- and 35cc will net about 185 lbs +/-...........

I dont think i had a leak in the head.. remember im running flat top pistons so u should see higher PSI #. no??

The PSI numbers ur talking about are correct when using the ADA head with stock 701 cylinders.. :dunno:

 

[sflsurfrider]

i believe im running
135 hi
125 lo
32 lbs popoff w/ stock arrester


also, maybe try to close the bottom and middle adj screws and open the top one a full turn.

 

[waterfreak]

I'm running the same set up (85.5 61x big bore flat top) with a single 48mm freestyle carb. My jetting is 135 main, 125 pilot, 2.0 needle and 115 gram spring. pop off is 32 psi. My boat ripps!!! You can ask anybody that has ridden it! There is no dead spots whatsoever and it pulls like a mofo on bottom.

steve

 

[sflsurfrider]

I'm running the same set up (85.5 61x big bore flat top) with a single 48mm freestyle carb. My jetting is 135 main, 125 pilot, 2.0 needle and 115 gram spring. pop off is 32 psi. My boat ripps!!! You can ask anybody that has ridden it! There is no dead spots whatsoever and it pulls like a mofo on bottom.

steve

:werd:

 

[WaveDemon]

I'm running a very similar motor (WF - 86 mm, single aftermarket carb, ported, 61x case, domed pistons) and it is the hardest hitting motor I've ever ridden. Mine even hits hard with 150 psi. Everyone who rides it has a huge grin on their face when they get off. There is definatly more potential in your motor.

 

[Jr.]

I have been in contact with Zane today, He is on the right track.
as with any new combo, there is tune time......... He's getting there
Thanks for all your input in helping him :headbang:

 

[Yamah0]

I'm running the same set up (85.5 61x big bore flat top) with a single 48mm freestyle carb. My jetting is 135 main, 125 pilot, 2.0 needle and 115 gram spring. pop off is 32 psi. My boat ripps!!! You can ask anybody that has ridden it! There is no dead spots whatsoever and it pulls like a mofo on bottom.

steve

This is exactly what i ran on the 49mm Full Spectrum few hours ago and it didnt go. It seemed too lean and would want to shut off when i hit the gas...

So then i changed the 125 to a 132.5 and it was a lot better but still not right... it seemed rich down low when i first hit the gas... like BoOorr.... BRAAAAAAAP:dunno:

Was told that i need to run a 2.3 rather than a 2.0 and and put the 125 back and ill be fine... I just got a 2.3, so we'll see tomorrow:woot:

Should there be a difference in jetting, n/s and spring between the 48mm and 49mm?

BTW... Is there somewhere i can read/learn about popoff?

Thanx
Zane

 

[freestylegeek]

...

BTW... Is there somewhere i can read/learn about popoff?

Thanx
Zane

Right here:

 

[parrdaddy]

This is exactly what i ran on the 49mm Full Spectrum few hours ago and it didnt go. It seemed too lean and would want to shut off when i hit the gas...

So then i changed the 125 to a 132.5 and it was a lot better but still not right... it seemed rich down low when i first hit the gas... like BoOorr.... BRAAAAAAAP:dunno:

Was told that i need to run a 2.3 rather than a 2.0 and and put the 125 back and ill be fine... I just got a 2.3, so we'll see tomorrow:woot:

Should there be a difference in jetting, n/s and spring between the 48mm and 49mm?

BTW... Is there somewhere i can read/learn about popoff?

Thanx
Zane

Full Specs are different animal to jet, they seem to be affected more by smaller changes in jet sizes. I would suggest calling Ed.

 

[Big Kahuna]

missed the part about about being Flat top pistons..........

definately open the top and close the mid and bottom....

 

[Yamah0]

missed the part about about being Flat top pistons..........

definately open the top and close the mid and bottom....

And others say definatly open bottom and close top and middle:17:

 

[Big Kahuna]

And others say definatly open bottom and close top and middle:17:

Well, you want bottom power right, that is the top screw, the middle is for midrange and the Bottom Screw is for Top end................ That why I say run the bottom and mid closed.........

 

[freestylegeek]

Well, you want bottom power right, that is the top screw, the middle is for midrange and the Bottom Screw is for Top end................ That why I say run the bottom and mid closed.........

ah, you non-flattopper...
Things are slightly different in the 'high performance' world. :biggrin:
'b' pipes are even MORE engine specific once you get into that kind of thing.

I would start almost dry (bottom screw open a tiny bit - verify with a garden hose), and then fiddle with the top screw 1/2 a turn at a time. Do the same with the middle screw. This should give you a good indication what general direction you need to go. Once you find out what screw has the effect you're looking for, then start dialing it in with 1/8 turn increments.

My flat-top Lamey needs TOTALLY different settings than my domed ported stocker used...

 

[Big Kahuna]

That is true "Ole Metal Flake God"........... Kinda like tuning carbs!!!!!!!!!

 

[superramjet]

full spectrums have the returns drilled out and run a jet in the return line. Are you returns restricted at all?

 

[Don 79 TA]

i had a setup like that back in 03
made some nice mid and upper rpm power
i ran a single 48
personally i think it's to many CC's to fuel with a single carb
I ran 240psi
while it improved it, it still wasn't what i wanted.
at that time i was dead set against dual carbs, have to say the fuel mileage was awesome.
i did try another carb, and made a massive difference down low, how ever the upper and mid fell off, again wasn't tunned on my setup, just something we swapped to see

as Paul had said it's a new combo and yes tunning is needed.
the draw back to a single carb with big CC's is getting it dialed just right.
I'd think duals could possibly help
also we bumped the static timing a little, and that helped too

i also had a 760 cyl, and personally prefer the 701 cyl for bottom end hit/response, again just personal preference.

if you can try dual carbs