.21 valvola engine question.

[Tofastformellow]

will do next time out..got too windy today...
is this the correct fuel nipple for the .21 CMB VALVOLA.

I was told by a very knowledgeable member it should have a chamfer on the inner hole.

http://www.intlwaters.com/index.php?automo...=si&img=892

what motor are you tunning ?? a green head valv or the newer red head valv with the shorter drum?

from the factory the green head valv does have a chamfer in the nipple feeding the engine .

when you toss out the factory 3rd channel needle valve and install a longstroke nipple , you loose this feature , and it can cause some headache in setup with regard to progression , lean up top and correct down low .. or correct up top , and rich down the middle and low end..

either ditch the lowend needle altogether ... or

i would order an actual 21 Valvola Nipple...or ask a switched on supplier to get you one in ( and not just sell you another longstroke one as they do fit..) , or mod it like the factory .. i have found my engine runs very well with it in there all stock..

from 20% to 70+% nitro the range of adjustment is in the needles on the factory stock carby to run very well..

Jason

 

[Dan Hydro]

will do next time out..got too windy today...
is this the correct fuel nipple for the .21 CMB VALVOLA.

I was told by a very knowledgeable member it should have a chamfer on the inner hole.

http://www.intlwaters.com/index.php?automo...=si&img=892

what motor are you tunning ?? a green head valv or the newer red head valv with the shorter drum?

from the factory the green head valv does have a chamfer in the nipple feeding the engine .

when you toss out the 3rd channel needle valve and install a longstroke nipple , you loose this feature , and it can cause some headache in setup with regard to progression , lean up top and correct down low .. or correct up top , and rich down the middle and low end..

either ditch the lowend needle altogether ... or

i would order an actual 21 Valvola Nipple...or ask a switched on supplier to get you one in ( and not just sell you another longstroke one) , or mod it like the factory .. i have found my engine runs very well with it in there all stock..

from 20% to 70+% nitro the range of adjustment is in the needles on the factory stock carby to run very well..

Jason

Terry is trying to tune a Green head valvola with a 3rd channel needle valve, but it looks like the nipple was replaced with the one from a long stroke (no chamfer) I have a green head long stroke and the nipple in his pictures are the same has mine.

Starting to think that, thats the cause of all his problems.

Dan.

 

[Tofastformellow]

quote "Terry is trying to tune a Green head valvola with a 3rd channel needle valve"

i have to change this :

Terry is trying to tune a Green head valvola with an AFTERMARKET REMOTE 3rd channel needle valve

i have pm'ed him , with some info that works on my valv..

Jason

 

[Ken Retallick]

McCoy No 9 plugs???

Put a 59 in it!!!

Or K&B 1L

 

[Tofastformellow]

LOL's

Jason

 

[Dan Hydro]

LOL'sJason

oops forgot the aftermarket part,

Sorry Jason, my bad. LOL

Dan.

 

[tmunn]

thanks ken that is exactly what jason told me to do with the plugs ...are you SA boys teaming up on me. :lol:

Here is what I have for plugs.

os #8

odonell purple dot

k-b 1L

mccoy 8 and 9

thanks everyone .

maybe testing tuesday night ?

 

[tmunn]

Guys

I finally have the engine setup pretty well it is starting very well idling and will take off and run like crazy from the launch.

I will experiment by leaning in the lsn some more next time out.

I am however only running the x437/3 or the x438/ 2.It seems to like these props the best and cannot seem to get the m or x440 to run well and stay on pipe. with the 440's, it comes off pipe and takes forever to get up on pipe and sometimes wont unless you bring it in and launch it again.

Would the fact that i am only running 30% nitro explain why it won'r run well or turn the larger props or is that determined by pipe length and other variables.

with the smaller 438/2 or the 437/3 I can get it running pretty well to the point that it will only ocasionally come off pipe and then get right back on if i make the boat cavitate a bit.

If i go wot there is no issue but if i back out of the throttle to avoid a wake or another boat it will bog and not pipe up without me making the prop cavitate.By that time the other boat is gone.

any suggestions

Thanks

Terry

 

[Watercadet]

Guys
I finally have the engine setup pretty well it is starting very well idling and will take off and run like crazy from the launch.

I will experiment by leaning in the lsn some more next time out.

I am however only running the x437/3 or the x438/ 2.It seems to like these props the best and cannot seem to get the m or x440 to run well and stay on pipe. with the 440's, it comes off pipe and takes forever to get up on pipe and sometimes wont unless you bring it in and launch it again.

Would the fact that i am only running 30% nitro explain why it won'r run well or turn the larger props or is that determined by pipe length and other variables.

with the smaller 438/2 or the 437/3 I can get it running pretty well to the point that it will only ocasionally come off pipe and then get right back on if i make the boat cavitate a bit.

If i go wot there is no issue but if i back out of the throttle to avoid a wake or another boat it will bog and not pipe up without me making the prop cavitate.By that time the other boat is gone.

any suggestions

Thanks

Terry

30% is really not doing you any favors. Are you at any kind of elevation?

Remember too, running a small prop and letting that Valvola scream like a Dremel on crack in not a bad thing.

 

[Tofastformellow]

LOL's Dremel on crack...

thats just funny . with the LS out on my motor it actually sounds more like a mac 21 .. dont know why ... :lol:

put some risers on the front of the sponsons , stick it on 60% and run a 44-45mm prop.

you got email terry

Jason

 

[tmunn]

ok i think i am on the right track now with the engine and agree with you guys that on 30% she won't turn the larger props.

i atleast know now what the problem is.

what makes it run well for 4-5 laps and then when you back ot of the throttle a bit it won't pipe back up right away ?

jason

you probabaly answered it in an e-mail I will check them for it.

thanks again

 

[shoboat]

Terry,

Your real problem is the cup on the trailing edge of your propellers,it needs to be reduced.

Too much cup loads the motor,back the cup off and watch her run. :lol:

Have Fun Testing,

Mark Sholund

 

[CharlieB]

When I was having the exact same issue it drove me crazy. I checked the fuel system and preasure line. I decide to take the engine down and found the cause.

A .25" piece of gasket was missing from the rotor cover. At 1/2 throttle the engine just screamed, but when I opened the throttle bore it went too lean an took out plugs. In short, the new gasket fixed it. If your needle investigation doesn't help, look for an air leak. H.T.H's Charlie.........

 

[tmunn]

Guys

I just got in from tuning and she is working very well now with only one small problem.

I can bring the boat to a crawl and punch it it will take off like crazy and right up on pipe and as long as you stay WOT or almost WOT everything is fine and it will run until she is out of fuel.no problem...

Same thing from launching from the beach .Radio in one hand launch with other and up on the pipe and plane she goes.Stay at WOT or Almost WOT no problem she'll suck the tank dry if i let it.

Here is my only issue right now if you back out of thr throttle to less than 3/4 -1/2 she will come off pipe and not pipe back up unless you give her a little twitch or left turn and then away she goes back up on pipe and will run fine.

I am pretty confident i have the engine issues worked out and many thanks to those who helped.. +

I also just this evening have worked out my balance and C/G issues.

I added 3oz of tape weights to inside of the sponsons at the top/inside as an experiment..NOT pretty but wow what a difference.

I figured that i could get away with less weight farther forward than inside the engine well up by the tank <_<

It was very windy and she never blew over once and the was nice and flat the whole way around the track.

i am going to leave them there and if they fall of i will replace them only epoxy them in place.

Mark

Is it difficult to back the cup off and does that sond like the problem described above.

.I have not done it before.Could you explain what to do if i pm'ed you my e-mail addy.

Thanks

terry

 

[Don Ferrette]

Try some 50%, 60% would be even better!

If that's not an option, pull the pipe out 1/8" or take just a little cup out of the prop. B)

 

[tmunn]

Since I do not know how to take the cup out of the prop i will try pulling the pipe 1/8 next time out.

This not getting right back up on pipe is the only issue I am having trouble with now.

I added some tape weights to the inside edge of each sponson and the boat handles

EXCELLENT now pops aross the wake and no hint of blow over.Nice and flat and more of the rear of the boat out of the water and no sign of stuffing.

Terry

 

[Roxyflash]

Do you restrict the water any?Sometimes the 20 motors need a little more heat to get them singing.When you bring it in how hot is the head?I take the the nipple of the rudder and tap the inner hole for a set screw then take some set screws and drill different size orifices in them small to large.Srew one in the brass nipple then screw in back in the rudder.Running a mc coy 9 needs some more heat also plug the plug element down grab the two last coils in the plug with a pick and pull the element down.This will advance the timing on your motor it may wake it up wont know till you try it.

 

[tmunn]

I do not restrict the flow of water and the engine runs very cool propbably only about 100-110 degrees.And you can place your thum and forfinger on the case with no fear of getting burned.

Earlier on in the year i actually re-worked my rudder like some do to alow more water to enter and keep the head cool.

I was only seeing a fine mist comming from the water outlet.Now I have a full bore stream.

I can restrict the water line with a zip tie to reduce the water flow as an experiment.

I was concerned about the engine not getting enough coolant and perhaps should not have been.

I will experiment.

I am now running a mccoy 59 and that is much better.

1)what is a safe operating temperature for the .21 valvola.

2)as the temp goes up when i restrict the water flow will I have to go in or out on the LSN or HSN ??

Terry

 

[Don Ferrette]

I do not restrict the flow of water and the engine runs very cool propbably only about 100-110 degrees.And you can place your thum and forfinger on the case with no fear of getting burned.
Earlier on in the year i actually re-worked my rudder like some do to alow more water to enter and keep the head cool.

I was only seeing a fine mist comming from the water outlet.Now I have a full bore stream.

I can restrict the water line with a zip tie to reduce the water flow as an experiment.

I was concerned about the engine not getting enough coolant and perhaps should not have been.

I will experiment.

I am now running a mccoy 59 and that is much better.

1)what is a safe operating temperature for the .21 valvola.

2)as the temp goes up when i restrict the water flow will I have to go in or out on the LSN or HSN ??

Terry

Getting some heat into that motor can't hurt. A real simple way to know if your at a good running temp is that when you bring it in you should only be able to hold the top of the motor for about a second or two. Sounds like it's running a little on the cool side. B)

 

[Brad Christy]

Terry,

A good 21 will run like a top at about 220-240 degrees head temperature. A VERY reliable source tells me that they are running their 21's in this temperature range, at about .002" head clearance with no detonation and no plug loss. The hotter they get, the cleaner the fuel burns. Just what I'm told. Don't shoot the messenger.

I've been restricting my water for years. I also pull the plug element out (about two coils) and run a bit richer mixture. Try this and see if it helps.

Thanks. Brad.

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