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Post by dpress on Jan 15, 2020 11:25:58 GMT -5
I seem to have caught the bug because this is my 3rd Homelite now. I have just bought a Terry made saw, which is named as a VI Super Mini, but I believe it belongs to the Super E-Z family. The saw has a U/T number 10199 and serial number 2343T286. The carb fitted is an HDC model, although I can't seem to find a number on it (there is a date stamp from August 1972), so I am assuming the saw is from that era also. My issue is that the carb is flooding very badly when the saw runs - at anything approaching full throttle fuel is spitting out of the carb and pooling in the air box. When I got it today the airbox area was very dirty with fuel and sawdust residue, caused I think by the fact that the manual oiler had been removed, but a hole left at the back of the air box where the oil lines entered. The area under the carb was particularly bad, and when I took the carb off I found there was sawdust in the vent hole leading to the diaphragm. I have stripped the carb and fitted new gaskets and a new inlet needle, and both Hi and Lo settings are as per the manual, but it is still spitting fuel out at a real rate. Judging by the amount of oily residue everywhere I think this issue has been going on for some time! I am in the UK so parts are not easy to come by, so I would appreciate any advice on what might be causing my problem. Many thanks, Steve
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Post by undee70ss on Jan 15, 2020 12:11:32 GMT -5
Most likely the inlet needle is leaking, easiest way to find out for sure is to pressure test the carburetor. Anymore I pressure test every carburetor before installing.
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Post by fossil on Jan 15, 2020 12:19:23 GMT -5
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Post by dpress on Jan 15, 2020 12:49:39 GMT -5
Thanks for the replies and suggestions. I suspected a inlet needle leak but have no pressure tester at present unfortunately. However the needle is new and the seat looks okay. I have retained the old diaphragms which are still very flexible, and don't suffer with the too tall rivet like the one in my rebuild kit! I will remove the carb again, and see if I can check if the valve is seating properly - perhaps with a length of hose with some fuel in it and see if it leaks with the cover off. I just wondered if the symptoms I have might have been caused by the check valve these carbs are fitted with, or if a defective check valve leads to fuel starvation rather than flooding? The inside of the carb was as clean as a whistle so I am a bit surprised it is flooding so badly. The end of the metering lever is set level with the base of the carb (with gasket) which is as per spec I believe, and I don't think the circuit plate had been off for a long time (if ever) as it was stuck solid in there.
Steve
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Post by fossil on Jan 15, 2020 13:09:01 GMT -5
Defective check valves can give some pretty weird symptoms. I've had saws that would only run with fuel running out of the muffler and others that tuned nicely and went lean after about 20 seconds.
The HDC and WT carb check valves are easily damaged with high pressure air. They may also be sticking.
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Post by fossil on Jan 15, 2020 13:15:47 GMT -5
For the height of the metering lever. No gasket. It should be level with the body of the carb. Look at the last page of the manual. If you used a gasket, the lever will be far too high.
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Post by dpress on Jan 15, 2020 13:43:15 GMT -5
Fossil thanks for that. I had got myself confused when reading that paragraph, and having looked at it again I will need to check and adjust the metering lever. I think age is beginning to addle my brain (or it is petrol fumes doing me in....) thanks, Steve
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Post by charles on Jan 15, 2020 13:55:09 GMT -5
Would trash under a Reed Valve cause similar problems ?
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Post by fossil on Jan 15, 2020 14:12:32 GMT -5
Would trash under a Reed Valve cause similar problems ? I don't think so. They would likely cause a hard start issue. If your valve(s) are leaky the carb spit back increases quite a bit to where your air filter will be soaked. There could well be more symptoms.
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Post by dpress on Jan 15, 2020 15:37:48 GMT -5
Just got back in after another hour or so at it - I had to finish putting together my little XL to clear some space! I have adjusted the metering lever - it was too high so I will see if that cures it tomorrow - I can't test it now otherwise I will fall out with the neighbours! I also need a new duck valve for the fuel cap which is leaking badly, and had the dreaded black gunk where there should have been a valve. If the flooding problem persists then I shall have to try and check the reed block - can it be removed without taking the whole saw to bits?
Thanks, Steve
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Post by fossil on Jan 15, 2020 19:25:28 GMT -5
I don't remember and I don't have a VI model of that saw. The reeds should cause a flooding issue and you can see them when you remove the carb and the carb adaptor to see if they are sealing and that they aren't cracked or broken.
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Post by dpress on Jan 16, 2020 9:48:45 GMT -5
Okay, so I had another test session today, and still have the same problem with fuel spitting back out of the carb mouth and pooling in the airbox. I am now going to check the reed valves, but would appreciate if anyone could advise on how I remove the reed valve block - is there a video or a user manual anywhere? I have looked at lots of Leon's videos but haven't yet found one that covers that operation, and if I just reply on the parts diagram I am liable to break something.... Any advice or pointers would be very welcome.
thanks, Steve
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Post by onlyhomelites on Jan 16, 2020 15:29:00 GMT -5
Well it's not too tricky, but you have to be careful with the screws. The screw heads are soft, so you need a good #2 Philips with a long round shank. I've found that I can pull the carburetor and just reach the 3 screws on the intake block...once you get them out, you can carefully pry the reed block and retainer loose. The other way to do it with better access is to remove the throttle handle entirely; but I like to save time and not risk tearing up the throttle handle to crankcase gasket.
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Post by dpress on Jan 17, 2020 7:15:27 GMT -5
Success (after a fashion). Thanks again to everybody who has commented on this thread. It appears it was a reed problem - I have attached a photo of the chip of wood that came out with the reed block! It was a wonder it ran at all. 3 of the reeds stayed on the block when I withdrew it, but one fell off into the air box along with the chip of wood, so I am sure that was the issue. Now that problem is over, it seems that I might have fiddled too much with the metering lever height, because although running, the saw now dies out after a few seconds as if the fuel level is not right, but at least there is nothing being spat out the mouth of the carb anymore! A bit more work to do this afternoon.... Cheers, Steve
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Post by onlyhomelites on Jan 17, 2020 14:23:03 GMT -5
That's a pretty damned big chip to make it all the way to that point!
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Post by dpress on Jan 17, 2020 15:57:43 GMT -5
Looks more like a witches tooth, and was quite smooth, so heaven knows how long it had been there. I have kept it for posterity...
Steve
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Post by charles on Jan 17, 2020 16:57:57 GMT -5
That was a "cheap" fix ! Lucky you didn't lose the engine ! Hope that solves your problem
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Post by dpress on Jan 18, 2020 6:44:50 GMT -5
I pulled the exhaust off and checked the piston/bore as best able, and all seems good. There is a little carbon build up (some black staining) on the side of the piston, but no score marks or any evidence of seizure. Last night when it was quiet I stripped the carb again and took my time thoroughly inspecting and cleaning it some more. I set the HI and LO needles as per the Walbro HDC guide, which is 1 turn out for both, reset the idle screw and today it started after about 10 pulls and settled to a steady idle straight off. After running for a minute or 2 I stopped it, fitted the filter and did a warm restart first pull, so I think that saw is ready to go! I have got a couple of Mantis tillers to service next, so still some more fiddling to keep me going....
Steve
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Post by sweepleader on Jan 18, 2020 8:10:36 GMT -5
You don't mention how it runs at high speed. Be sure to adjust the high speed properly so as not to risk a lean condition when cutting. Glad to hear it is running well.
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Post by dpress on Jan 18, 2020 11:30:38 GMT -5
Thanks, I did rev it up a few times to clear it out and the carb seemed spot on, transitioning between LO and HI with no stumble at all and revving out well, but I will need to find a tree to chop down so I can test it under load, and get it properly dialled in. I didn't want to run it for too long today as it oils really well, and was making a right old mess everywhere! All told I am pleased with the result. A new duck bill arrived in the post this morning, so that has been fitted to the fuel cap, and I think that is just about it finished now. On to the next one....
Steve
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