g741.org

This weekend's plans called for installing the cab top supports I got from XM708. Well, the M started and moved but wouldn't start again when I needed to reposition it and I smelled fuel so I thought I might have flooded it. Anyway, pulled the oil bath-fuel in the elbow-not good; drained the elbow then removed it-worse, fuel all inside the very top of the carb with a drop hanging on the vent tube. So I pulled the carb off, got all of the fuel out of the intake (puddle), then reinstalled the carb and turned on the electric fuel pump-fuel filled the carb reservior and continued to the point of spilling over the carb sides and shooting fuel out the carb vent tube! Oh what fun-needle valve or float stuck! So I pulled the carb back off, drained the intake again, then reinstalled the lower half of the carb only, set the float level and powered up the pump again. It took several tries to get the float level correct- the needle valve appears ok so it looks like I'm going to be ok, right? Wrong-when the carb linkage is removed it leaves the carb with a wide-open throttle, and as a result, when it started, it revved up to the red-line and the governor thankfully shut it down. Lesson learned-never underestimate the roar of the 230 in flight!

My concern is now I hear a slight ticking sound when idling, perhaps a lifter, and I'm honestly surprised that the 230 didn't go into full cook-off detonation mode. The good news is that it still runs, and smoothly at that. I'm not going for a rebuild at this time but wanted to share this for those of you who might be saved such trama when tackling your engine and carb.
Gary

we ended up installing a new needle with rubber tip, and the electric pump we use as a backup will overpower that, probly need a full pressure regulator if using a electric pump

I was having problems with fuel getting into my crankcase. Was told it was probably my electric fuel pump over powering the needle valve, etc. I installed a mechanical pump back on the engine and it seems to have alleviated the problem. Why not consider switching back to a mechanical pump?

we have the rebuilt mechanical we run on and the electric is there for emergency since it was there when we bought the truck

Thanks Folks!
I've considered returning to the mechanical pump but I've read and herd so many horror stories over the diaphram leaking fuel into the crankcase oil that I'm more secure with the electric pump.
Gary

Hmmmn, so you'll believe all the stories without even trying a mechanical? From what I've read you'll get years of good service from a mechanical before having to worry about the diapragm deteriorating....What can you lose with the trouble you're already having with the electric?

Nickathome wrote:Hmmmn, so you'll believe all the stories without even trying a mechanical? From what I've read you'll get years of good service from a mechanical before having to worry about the diapragm deteriorating....What can you lose with the trouble you're already having with the electric?

As long the mechanical pump is properly rebuilt using new (not NOS) diaphrams & valves that are compatible with today's gasoline, you will be good to go for many years. The diaphram cracking problem comes from using 50 year old military rebuild kits with the diaphrams being in a deteriorated state right out of the box. The material they are made from is not compatible with today's fuel blends thus it will destroy the diaphram really fast. All of these gas spilled into the cranckcase horrors people experience are 99.99% due to this issue. Bottom line, saving a buck on an NOS kit isn't worth the risk of destroying your engine, but some still insist on doing it, go figure.

My son opened the box with our rebuilt carb from Jim.... we have not blinked for 2 days... staring in disbelief at what a great job he did. Totally disassembled, cleaned, plated, new screws, bolts, nuts, gaskets,.... the works. We had it on the table as a center piece before the wife came home.... I'll post some pics but it looks the same as John's at MW is hosting.

Thanks again for the replies-this is the first trouble I've had since I replaced the carb. I don't feel the fuel pump nor the carb were faulty, especially since I got the rebuilt carb from John Bizal at Midwest and it really is a gem of a carb, as described by knattrass, and I back John to the hilt concerning the quality of his parts, and especially his kindness in helping address any of my M37 needs.

I suspect a little chunk of crud got through the in-line filter and pinned the needle valve so I will replace the filter-cheaper than going to a mechanical fuel pump. It also does not help that the truck is still not roadworthy-close but not quite, so I don't get to run it around much. Another month or so, perhaps.
Gary

knattrass wrote: We had it on the table as a center piece before the wife came home.

And you moved it...why?

So they could run the truck!

No,so they could keep the truck!!

And sleep in the house.

once you rebuild it, it should not go bad again, be sure you have a fuel filter between the feed line on the frame and the pump

Well you folks might remember I'm doing all this M37 work in my apartment complex-need to move it to a different space every now and then to keep the management off my 6....

Sorry, I jumped to my rebuilt carb and re-read your message on the pump. I had Tony at Then&Now do the rebuild on my pump. It took about a 2 weeks turnaround for $95. Tony did a great job and returned all parts. You may want to consider unbolting yours and sending it out. The difference for the cost of the kit was around $50 - pretty cheap when you see what Tony does.