rmh

Jack - I am not trying to proove or disproove anything
If I have upset your applecart
that's just too bad. I was just ramblin on about stuff about carbs I have worked with for a few years
You want numbers - go look em up I am going to go read the paper -

jack1933

My Feedback: (2)

You have not done a thing to my applecart, all I can see from your posts is,, this thread is not for you, so why waste your time on here, and the majority of folks don't give a hoot about tuned pipes, I sure don't, one more time IF YOU COULD NOT MAKE THE ZDZ RUN RICH, AT WOT, THEN YOU HAD THE WRONG CARB ON THE ENGINE, Just logical.

Kweasel

My Feedback: (29)

Your carb may not be too big if it won't draw at full throttle, unless peak power occurs below 70% open. I would add a stack first and then look for the bottleneck in the high speed circuit before I changed carbs.

tkg

My Feedback: (1)

!st statement, Yall got the wrong carbs on your 100-210cc engines.
Current statement, Yall got the wrong carb on your 100-210cc engine IF you can't adjust it rich at WOT..... duh really and you gotta to be a rocket scientist to figure this out??
Very BIG difference between those two statements.
edited to Correct displacement

captinjohn

Well I did not learn much from this thread, except where to get a good carburator for $12-13 dollars!! Gee I wonder if that carb could have had a fuel restriction that I was working on? I will check it again. Capt,n[:-]

jack1933

My Feedback: (2)

Hi Terry, Thanks for the input, Just what exactly are you trying to say? where has anyone stated 100150cc engines and same on the 100-150cc engines? Am confused , please explain.

tkg

My Feedback: (1)

Corrected displacement
Jack you started out with a blanket statement that the MFG's had put the wrong carbs on their 100-210 engines, you now are saying that if it doesn't run right the MFG put the wrong carb on their engine. Big difference between statements
Most of the MFG's have put the right carb on their engines for how we fly them (note fly not race) They adjust fine at WOT. There have been a FEW engine MFG who did not get right and soon the problem is noted on the net. Result no sales or fix the carb problem.

jack1933

My Feedback: (2)

Terry, Let me put it another way IF YOU CANNOT RICHEN THE HIGH SPEED NEEDLE ON ANY ENGINE AT WIDE OPEN THROTTLE, REGARDLESS OF THE DISPLACEMENT, THEN YOU EITHER HAVE AN AIR LEAK AROUND THE INTAKE SYSTEM, OR THE WRONG CARB (USUALLY TOO SMALL) HAS BEEN INSTALLED ON THE ENGINE. installing a Walbro Wga-7/9. that was calibrated, by Walbro, for a 100cc engine on a 150-157-170-210 is in fact installing the WRONG carb on the engine. And they do not adjust correctly. No one said anything about race anyway. So I still do not understand what you are talking about. Duh how much simpler does this have to be for you to figure it out?

tkg

My Feedback: (1)

I'm complaining about your "the sky is falling" statement when you start this thread. The FACT is that over 95% of the MFG's have the RIGHT carb on their engines.

tkg

My Feedback: (1)

OK so lets ask
WHO HAS AN ENGINE THAT WON'T ADJUST RICH AT WOT??????

rmh

A local friend who runs DA150's has swapped carbs n reed banks (different sizes) from DA100 - adjustments are just fine - midrange is better - top end power is down.
This is on an engine running tuned pipes so It probably is not relevant
Although-
The exhaust system affect the carb selection on ALL two strokers
I also should never have entered into this thread because frankly I don't understand what the f-is going on.

jack1933

My Feedback: (2)

Ok Terry, please stop with the complaning, and open your mind. The reason for the thread in the first place is to inform those interested why its important to be able to richen the mixture at wot. It is merely a reference point to acertain if the carb is suppling fuel at wot at the desired setting, thats all this is about. once this is known, then you can lean the hi speed needle to the desired mixture, usually I like to tune about 100 rpm less than maximum If you do not know how rich, or lean the carb is, at wot then you could not know, for sure, if the mixture is correct. I have had this sympton on several of the engines I've built, just recently on five 150cc engines made by other mfgs. Your statement that '(95% of the mfgs. have the right carb)" seems a little bit funny to me, how on earth would you possibly know this? Is it because you have contacted all of them, and they told you so, I think not. Hope this explains about the sky falling, gee whiz, if we cannot communicate on a higher plain than this, then this thread is not for you.

jack1933

My Feedback: (2)

Hello Dick If you cannot understand what this thread is all about, then why do you keep posting, with a closed mind, no matter what i try to explain, you just cant grasp it, please read the response to TKG, maybe this will enlighten you, if not , well I dont know how to explain it any better.

onewasp

Jack,

As an outsider to this discussion I suggest you re-read the posts and then tell me who it is whom has the "closed mind".

Yours is so closed it is unbelievable.

captinjohn

To quote jack.....Actual case in point. I could not get the high speed needle to richen at wot, on a 150cc engine with a wga-7 walbro, this was before any mods to the carb. I installed a wb-25 and got the high needle to richen the engine at wot, was testing for air leaks around the intake system, however there was no noticible increase in rpm, and the wb-25 has a larger venturi than the wga-7/9 at that point I started enlarging jets in the carb, it is responding well enough, so its still on the engine. Then I called walbro and was informed the wga-7/9 was calibrated for a 100 cc engine. The wb-25 is going to be installed on the engine, and I know it will work, because its already been on the engine. .................................................. .............................My reply... Walbro told you the wga-7/9 was calibrated for a100 cc engine. But you said you enlarged the jets and got it to respond well. So there is no sense in buying a differant carb. Maybe the wga-7/9 was not made right in the first place. BAD on arrival! Anyway you cuould get it to run rich enough. Right??? Capt,n

jack1933

My Feedback: (2)

Right, So there was no reference point to adjust the hi needle.5th wga-7/9 that has responded this way, recently.

jack1933

My Feedback: (2)

Colsed to what exactly. All I am trying to do is inform other modelers about a serious situation, If you cannot understand what this thread is all about, then it is not for you. Negative comments are not what RCU is about. personal attacks are unacceptable on here.

Kevin Greene

My Feedback: (85)

Would you part with one of them???....I've looked for days on the 'Bay w/no luck...Just my luck, several months ago a buddy of mine needed a 76-A carb for his Brison 3.2 and I found a dozen for sale by one individual on the 'Bay...Of course I didn't buy one for myself...[:@]...

Kevin

oceansfiftyseven

Jack, your the only one making rude comments on this thread. You've made your point. Many times already.

jack1933

My Feedback: (2)

Im sorry you think Im making rude comments, all I was trying to do is relate to you a problem I was having. If i did not make it clear, my fault, thus the many repeats of the problem. I dont know whether some just dont understand the problem. I only responded to rude comments when directed at me. Suggest you read all the posts.

captinjohn

Are you saying that is 5 five wga-7/9 carburators responded the exact same way? What do you call a reference point...is it like 1-1/2 turns open? Now if that was five carbs, how many others did you try before and did any of them adjust ok? I am trying to get the total picture here and maybe learn something! Thanks Capt,n

onewasp

What personal attack???? Where ???

A statement of the obvious qualifies?
I think not.

Through what great act of benevolence did you grace us with your presence ?
That is surely what seems to be the attitude presented here.

jack1933

My Feedback: (2)

Thanks capt,n, for the positive response. All the 5 150cc engines I worked on recently did exactly the same thing, I could back the hi speed needle all the way out, then turn it in 1 turn, or if you will , back the hi sreed needle out 4 turns, in that case the hi speed needle is no longer controlling the fuel flow to the main jet, the engines continued to turn max rpm, of course that was different for each engine, however none of them allowed the engine/s to run rich. The reference point I'm refering to here is this: one does not know for sure where the rpm should be, if one cannot have a rich run with the hi speed needle. Lets say you want to be 100-200 rpm less than max, with these wga-7/9 Walbros, there is no way you can determine your target wot rpm. I like to fly IMAC, and there are a lot of uplines, and at 95-100 degrees, ambient, I do not want a sagging engine during a contest. As far as working on 150cc engines in the past 15 years or so, I never had one that would run rich (reference point) by opening the high speed needle, Sorry for the confusion, hope this is a satisfactory explantion. If you, or anyone would like to call me regarding this, my phone no. is 580-276-5322.
Regards to all
Jack

jack1933

My Feedback: (2)

Sorry you feel this way, if you think something benevolent is the reason im on here, ok However 30 years flying giants, and building large two stroke engines should count for something. By the way, How many 150cc and up do you have in large scale airplanes?

captinjohn

Jack, are these engines you are talking about that will not go rich, is that on a test stand or in airplane? Just for data on this...what Prop...what is hi RPM (average will do)....what is the placement of fuel tank and how big of lines and or filters are you using? I caanot for the life of me figure out why five of the same carbs will not richen up. For every happening there is a cause...I would think! Thanks, Capt,n[X(]