mvarzoni

friends,

I've converted my st G90 to gas, It got ok with the stock carb, while the engine where on th straight position, up heads I mean ...
But now, it is up side down on an Extra 260 and it is failing a lot, So I decided to put a walbro carb on it, but I cant manage to fit the walbro carb on the G90 case,
I got an adapter mechanized wich is very well made, but the carb body hits against the engine's body...
I could mechanize another adapter with some angle, about 15degree, would be enought, but I'm not sure it would prejudice the engine air taking.

Has anyone here converted a G90 and used a walbro carb?
If so, what walbro carb number are you using?
do you have any pictures of the adapter?

Thanks,
Mauricio

Ralphbf

My Feedback: (27)

Try this guy

http://www.lambertsrc.com/

w8ye

My Feedback: (16)

The carb is a WT-173 Notice that the regulator side of the carb is against the cylinder. Notice that the cylinder has been machined for clearance. Notice that the carb is turned slightly to clear the exhaust manifold[img]{akamaiimageforum}/upfiles/265816/Vt57472.jpg[/img] The engine is a Super Tiger S90K version and not the G90 version. The engine belongs to Jezmo.

mvarzoni

ok, thank you for your reply, but I still have a question.
What if I incline the carb 15 degrees forward? would that affect the engine tunning some how?


Thank you.
Mauricio.

w8ye

My Feedback: (16)

As long as the carb does not hit the propeller, it will be fine. Will not effect airflow through the carb

av8tor1977

My Feedback: (6)

Another choice is to use a ZAMA carb. They are slightly smaller physically, but have the same bolt pattern. Sorry, I have no ZAMA carb numbers.

To put a Walbro carb on my Super Tiger .91, all I had to do was turn the carb a bit sideways, and grind down one of the regulator cover screws a little bit.

The 15 degree inclined adapter manifold should be no problem, if as W8YE says, it doesn't interfere with the prop.

AV8TOR

captinjohn

Hellow AV8TOR: Have you ever tried L85 gas with 18oz oil per gallon...a OS "F" glow plug witha a tad of acetone added. It works real good in The bigger SuperTigers. I seen it done at a club in Indiana. Here is a couple of Photos....Take care My Friend. Capt,n

av8tor1977

My Feedback: (6)

Hi Captain,

I played with E-85 back when I first started with the Gas/Glow experiments, but couldn't get it to run without glow power, (at least not well), so I gave up on it.

Hey, I remember those old pics of mine! That Ryan's Rebel of my brother's did a "Figure 9" on a low level loop and got hurt last week. It is fixable though, and my brother is working on it. It just tried to recover from a loop at about 6 inches under the ground. It looked for a moment like it might make it with only a pancaked landing gear, but then it cartwheeled... []

The Giant Stik of mine is still flying great with the Echo twin cylinder on Gas/Glow. It has a Poulan 42cc on Gas/Glow on it in the picture.

Hope things are going well for you,
Take care,
AV8TOR

aero nut

Hi Bob sorry to hear about your bro's ryan, but it's fixable isn't ?

av8tor1977

My Feedback: (6)

Yes, it is fixable. He wanted me to ask you what covering you used so he could try to match it locally. He took the mag off and put the Ryobi on CDI, and it needed a good bit of weight in the nose to balance. I told him to extend the nose about 1.5" when he does the repair. (He has his servos in the tail area.)

How are you doing Bill? I have e-mailed you several times with no response. Got some weird e-mails from your address though, like a virus was sending spam or something. PM me and let me know if you have a new e-mail address, and how it is going for you.

Hasta Luego,
AV8TOR

mvarzoni

Dear all,

After a very long time working in a G90 convertion,I can say, this convertion works very well, but I have an OIL question.
When it was a glow engine, it was used to use 16% oil, but now on gas, should it use same amount of oil?

Another question, how bat could a battery quality affect the CDI / spark plug work?

Thanks
Mauricio

w8ye

My Feedback: (16)

With a plain bushing type (original) rod you willneed to run 16:1 gasoline / oil ratio

With a needle bearing rod conversion you can maybe get away with 30 or 32 to 1 with your gasoline/oil ratio?

mvarzoni

w8ye,
Where do I find those needle rods? even better, what is the dimention of those rods, in order to try to find locally in Brazil.

Mauricio

w8ye

My Feedback: (16)

In this engine conversion forum is where they have been talked about.

The people have custom made them using needle bearings available from stock.

Ken Lambert and BME engines are people who have made them

Look at the bottom of the page in this link
http://www.bmeengine.com/engines.htm

The G90 engines run very well at 15:1
http://www.youtube.com/watch?v=prDFn...layer_embedded

Ken Lambert can modify yours for you
http://www.youtube.com/user/kenlambert59#p/u

mvarzoni

Another question, how bad could a battery quality affect the CDI / spark plug work?

w8ye

My Feedback: (16)

It takes a 1200 mah NiCd or bigger for the RCEXL brand ignition.

I think they work down to about 3V

mvarzoni

W8ye, Thanks for the tip, it worked perfect on a 1200nicd pack.

Another question, Do you know the neil bearings size I must use on the G90 CONNECTING ROD?

Thank you
Mauricio

w8ye

My Feedback: (16)

Pictures from Ken Lambert ST2300 http://www.lambertsrc.com/engines.html

w8ye

My Feedback: (16)

http://www.impactbearing.com/brochurepg30.pdf

The crank pin will have to be replaced with a pin that is 58 Rc or harder

mvarzoni

W8ye.

What do you mean replacing the pin?
Do I need to cut the original out and drill and put a new pin?

Thanks
Mauricio

av8tor1977

My Feedback: (6)

Yes...

AV8TOR

KenLambert

My Feedback: (107)

Mvarzoni:



It is not as simple as cutting the pin off and puting another on. so please don't cut it off unless you want to buy a new crank.It must be machined out because the crank is one peice it doesn't have a replaceble pin.

captinjohn

Ken, Can you send me a PM...there is yet another person wanting to call you to talk about wanting you to install needle brgs in a SuperTiger engine. Thanks Capt,n..... PS...are you still in Texas?

KenLambert

My Feedback: (107)

John
I sent my # by way of email, I have uploaded some videos to my websight machining some crankshafts and a short tour of my trailer shop. Or can be seen on you tube under kenlambert59

av8tor1977

My Feedback: (6)

Well Ken, even after carefully watching the videos, I am still unclear on how you change the crankpin. I see you boring out the original pin. What do you do, bore it out until you have a press fit for the new pin, install the new pin, then machine/turn off the old pin down to the new pin??? I'm confused....

AV8TOR