Glow head brotherhood.
10-18-2014, 08:19 AM
#829
I got it brand new off RCU for $40. It took a couple gallons to really run well but it was a fantastic runner out of the box. It turns a 9x5 APC at almost 16k without a muffler.
10-18-2014, 09:48 AM
#830
Senior Member
I have been over the troubles with my 62 in the Club Saito forum to no avail. It runs fine for the most part until about 7 minutes into the flight then if you go below half throttle it dies, I suspect a main bearing not seated properly and when the case heats up sufficiently it causes enough drag to kill it at the lower throttle setting. I know its not the planes fuel system because my Saito 45 bolted up to it and flies the plane just fine. After it dead sticks you carry it back to the pits and fire it up and without changing anything it runs fine.
10-18-2014, 11:02 AM
#831
Okay, what am I missing? How does a hot case cause more drag? I don't see it but the list of things I don't see is quite long, so bear with me. 7 minutes equals just about half a tank of fuel. If it were a fuel draw problem then there is a chance it doesn't matter that your 45 likes the fuel system. Have you replaced every inch of fuel tubing...from the vent to the tank to the clunk to the carb? If you are tired of talking about this in the forums then PM me. But, the main bearings are going to be hot before 7 minutes and that may be something to consider.
11-03-2014, 08:15 PM
#833
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I need to stay off eBay for a while. Seems like everyone is selling off all the 2 strokes for gassers. I have bought 10 engines in the last 2 months. I think I may be addicted to Nitro.........
11-05-2014, 10:13 AM
#837
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[QUOTE=jeffie8696;11901657]I am going to bench test it before any further conclusions[/QUOTe
Have you considered just putting new bearings in it to see? I mean , if it were bearing failure, this would eliminate that possibility , and cheaply as well. Just curious , have you had a chance to bench test yet.
Have you considered just putting new bearings in it to see? I mean , if it were bearing failure, this would eliminate that possibility , and cheaply as well. Just curious , have you had a chance to bench test yet.
11-05-2014, 09:44 PM
#838
Senior Member
My Saito is still under warranty so I would not be inclined to open it up or change the bearings. However I did get a chance to do some bench testing and was able to replicate the results exactly, set needles as usual, run engine up for a few minutes and then pull back to about 50% throttle and it will die every time.
So I started messing with the needle settings and found it would run fine one click lean off 4 stroking (8 stroking?) two clicks and it will die every time.
It will richen up just fine and acts normally when setting high speed needle and the low speed needle is excellent, trust me I have been through the needles settings on this one. I use SIG 15% Champion and have changed the OS F plug too, I am using an 11X8 Pro Zinger at it tachs at around 10,000 static. Usually a lean high speed needle results in an overheat and stall at WOT this is the other way around so its perplexing. I can imagine a lean midrange causing it but this is ridiculous.
So I started messing with the needle settings and found it would run fine one click lean off 4 stroking (8 stroking?) two clicks and it will die every time.
It will richen up just fine and acts normally when setting high speed needle and the low speed needle is excellent, trust me I have been through the needles settings on this one. I use SIG 15% Champion and have changed the OS F plug too, I am using an 11X8 Pro Zinger at it tachs at around 10,000 static. Usually a lean high speed needle results in an overheat and stall at WOT this is the other way around so its perplexing. I can imagine a lean midrange causing it but this is ridiculous.
11-06-2014, 05:50 AM
#839
I posted about this in the Fox thread,but I'll add my GlowHead move here. Fox .50 with a bad piston/liner. Answer: use a junk MDS ABC P/L and head from a .40. Guinness beer can liner shim and a custom made wristpin. We bored the piston to fit the Fox wristpin and Fox .50 rod as the MDS rod small end was egged out real bad. It was in a crash. The MDS head fit though the fins are clocked a little. This engine is a work in progress so we have some modifications to make to it still.
This engine turned a 10x6 APC at 11,400 on 10% fuel and 12,200 on 25% fuel with a .036" head spacing. The MDS P/L had roughly 10 gallons on it and still a good fit.
This engine turned a 10x6 APC at 11,400 on 10% fuel and 12,200 on 25% fuel with a .036" head spacing. The MDS P/L had roughly 10 gallons on it and still a good fit.
11-13-2014, 06:15 PM
#841
The Guinness beer can didn't have enough taper by itself.... So we just used a junk MDS chromed brass liner on the inside and then the beer can to add some flair outside the liner. LoL.
Next assignment is to drop the liner (and beer can shim) to take advantage of the longer stroke of the Fox by getting the MDS liner situated so the piston is getting to the proper height in the liner and also tighten the head clearance. Currently it will turn a 10x6 at 12,200rpm on 25% nitro and 11,400rpm on 10% nitro (20% castor goo in both). We will be working on it this weekend perhaps.
Next assignment is to drop the liner (and beer can shim) to take advantage of the longer stroke of the Fox by getting the MDS liner situated so the piston is getting to the proper height in the liner and also tighten the head clearance. Currently it will turn a 10x6 at 12,200rpm on 25% nitro and 11,400rpm on 10% nitro (20% castor goo in both). We will be working on it this weekend perhaps.
11-15-2014, 10:10 AM
#845
Jeffie- I may be wrong on your specific problem but your symptoms are a classic case of a Saito having tank gravity pressure reduced for whatever reason and the low speed a bit lean. The low speed can be up to 80% of your throttle on a Saito. A little reduction in gravity feed and a little bit lean on the low speed with do what you are describing on Saitos.
11-17-2014, 01:43 PM
#847
We milled the deck of the Fox .50 / MDS .40 hybrid (dubbed FrankenFox) to square it up first off but moreso to drop the MDS liner to correct the port height and head spacing issue. The ports of the MDS liner are higher than the ports in the original Fox liner. This also created a .033" head spacing. The Guinness beer can shim got damaged during tear down so we cut a new one. Coors Light shim stock is .003", so we had to go back to the Guinness can shim stock to achieve the proper .005" liner to crankcase shim spec. I took a slow motion video of the first pass after squaring the deck: http://youtu.be/4sfmdaS893Y
If you look carefully, you can see the tiny chips flying away. This process gave the engine a 650rpm boost to 12,750rpm on a 10x6 APC and 10% nitro. There's a few more mods in the works on this engine, but maybe not until it warms up a bit. The 12,750 figure was obtained when the air temp was a messily 15F.
If you look carefully, you can see the tiny chips flying away. This process gave the engine a 650rpm boost to 12,750rpm on a 10x6 APC and 10% nitro. There's a few more mods in the works on this engine, but maybe not until it warms up a bit. The 12,750 figure was obtained when the air temp was a messily 15F.
11-17-2014, 02:07 PM
#848
For the crankcase heating up, I have a couple motors that just had too little clearance for the crank to case fit. I just polished the crank a bit, just not where it is supported under the rear bearing, and it solved the problem. Magnum pro .28 (T Tiger rebrand?) and a Norvel .25. Just a bearing misalignment or a few .0001" can make a difference. If it is under warranty, I would not touch it though. I also have a couple that have way too much clearance, and fuel pours out the front bearing opening. (Ucktam)
11-20-2014, 04:24 PM
#849
Hey guys,
I need some advise on this one. I bought an OS 108 FSR and the carb has been modified with JB Weld (I think) to make it a remote needle setup. I'd prefer to remove the JB Weld and get a replacement needle valve assembly on the carb. I don't have a remote needle valve for this.
Is is there a way to remove the JB Weld without destroying the carb body? Anybody have any experience with this?
thanks.
I need some advise on this one. I bought an OS 108 FSR and the carb has been modified with JB Weld (I think) to make it a remote needle setup. I'd prefer to remove the JB Weld and get a replacement needle valve assembly on the carb. I don't have a remote needle valve for this.
Is is there a way to remove the JB Weld without destroying the carb body? Anybody have any experience with this?
thanks.
11-20-2014, 05:03 PM
#850
Methanol will soften JB weld. Acetone may as well, but I've softened JB enough just soaking in methanol for a day or two to pick it out with a hobby knife and sharp pick.