Chris-PA
Where the Wild Things Are
LOL, this thing ain't never gonna see 220!
Exhaust Delayed Scavenging
- Thread starter Chris-PA
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bikemike
loud pipes save lives
I was half tempted to drill a new hole and press a pin just north of the transfer ports so I could port the intake.
Chris-PA
Where the Wild Things Are
What carb is on it? It sounds like it's pig rich on H. Although I like how the smoke blows out both sides!
I'm really curious if the ring end is on the port now. You know I played around with it while the sealant was setting up, and I saw the ring in the top of the port but don't recall seeing the pin or the ring end, although it could have been off to the side and obscured. That would be boneheaded if I missed it.
However, the chassis I used was advertised as having low compression, but it turned out there's nothing wrong with the engine, and it's an older one. I just built this one because it was different. So if I screwed this cylinder up I'll just cut down the better one and use that.
bikemike
loud pipes save lives
Yeah it is rich on high end and a Lil fat on low circuit too but the low circuit ports are spaced very far apart for a smooth transition. Plus I think it's a accelerator pump carb that isn't really pumping as it should. So like most all pumped carbs I've deleted the accelerator pump and run a torch tip cleaner through the 2nd and 3rd low circuit port and worked great on other carbs n saws. Just didn't mess with this carb yet just slotted splined needles so I can use a screwdriver. That running fat sound may also be the rev limiter too. I believe its,a 13k redline
bikemike
loud pipes save lives
For the ring location I put a mark with a sharpy about a 3/16" from the ring end slid it into the jug I think I'm about a strong 1/16" week 1/8" safe from edge of intake port
bikemike
loud pipes save lives
Prolly fold a rod or shatter rod bearings
Chris-PA
Where the Wild Things Are
I've never had a problem with the accelerator pumps - I like them because I don't have to set the idle as rich.
I have not detected any rev limiting on the Poulan ignitions. Have you run into any info about that? On my fastest one I run the older Phelan ignition & flywheel, but on this one I used the Walbro parts.
It would not have been hard to deal with had I even thought about it, but on the older cylinders I'm used to the top edge of the intake is lower and the ring never gets into it. I would have just widened the intake to one side instead of both - I have several saws where the intake port is not centered. I'll have to wait until I get home tonight to see if I made a grenade or not.
bikemike
loud pipes save lives
I'm pretty sure they are a rev limited coil. My pp4620avx on turns 13k with stock exhaust or pipe on a digital tacH sounds like the pullchit was turning the same no load and light load I heard it starting to cut out when I lean it out in a cut.
bikemike
loud pipes save lives
I noticed that too on the older jugs with the intake port running lower and if I'm not mistaken it is at a downward slope.
I might try relocating the pin on the piston one day so I can widen my intake I can't rotate my piston now cause the exhaust port is to wide now.
Chris-PA
Where the Wild Things Are
Well, I lucked out - there is no pin in the port, or ring end either! I'm betting it's really close, but it should be OK.
Here it is in all its glory. I had to use a mismatched clutch cover until I fix the brake on the green one. The muffler doesn't really look that rusty, it's a flash thing.
Now I can keep experimenting with this project.
Here it is in all its glory. I had to use a mismatched clutch cover until I fix the brake on the green one. The muffler doesn't really look that rusty, it's a flash thing.
Now I can keep experimenting with this project.
bikemike
loud pipes save lives
Did you slot the bottom half of you baffle out
Chris-PA
Where the Wild Things Are
I do them like the one on the right now:
That's an older picture but I've used that same method on quite a few now. I put the opening towards the bottom - you could cut the top of the baffle but I like to pass the exhaust through a longer path before exit.
bikemike
loud pipes save lives
Me too. Next on the bench is a poulan wood shark strato 42cc. to flip it's cosmeticly nice with all stickers. It's gunna get a Lil muffler mod and I punched out the main carb a bit cause my 36cc strato woke up nice with muffler mod and carb work.
bikemike
loud pipes save lives
My pullchit is slotted like that with some bottom fuel dragster pipes on it.
bikemike
loud pipes save lives
No pop up here I'd put 1 in my other saw first.
Chris-PA
Where the Wild Things Are
I don't have the welding capability. Would probably be a pretty heavy piston by the time enough material was added to make a difference?
I'm going to run it as is for a bit and see how it works, then probably raise the sides of the piston skirt for better transfer access. In the mean time I'm trying to figure out what they intended with the transfers as they are made.
Chris-PA
Where the Wild Things Are
I had a chance to work on a smallish pignut hickory that fell over a couple of years ago, but was still alive even though now sideways. I took the video camera along with the best of intentions of doing a before and after comparison, but it didn't happen. The saw ran nicely, certainly competent, but not exciting. Then the fuel line kept splitting and the filter kept falling off, so I had to fix that. And before I knew it the engine was out and the saw in pieces! I don't even take the handles off these anymore to pull the engine.
At Mike's suggestion I've been looking at the piston skirt at the bottom of the open transfers. Here is the problem - at BDC the transfer is almost blocked by the way the piston meets the counterweights (this is a cutaway engine - try to picture the transfer runner in line with the pin):
I decided to use another piston and make the cut for the intake narrower, leaving more distance between that and the notches I was putting in for the transfers. Here is the notch for the transfers (upside down):
I was conservative about how high to make them. I reasoned that the thing runs OK without them, so I was just trying to augment the flow, and these transfers are narrower than earlier versions anyway. Plus, I did not want to shorten the transfer length, although that was just on a hunch as I have no good reason for that yet.
I only had time to fire it up and cut up a small walnut branch. It actually felt noticeably snappier, and I'm looking forward to trying it out in some real wood.
At Mike's suggestion I've been looking at the piston skirt at the bottom of the open transfers. Here is the problem - at BDC the transfer is almost blocked by the way the piston meets the counterweights (this is a cutaway engine - try to picture the transfer runner in line with the pin):
I decided to use another piston and make the cut for the intake narrower, leaving more distance between that and the notches I was putting in for the transfers. Here is the notch for the transfers (upside down):
I was conservative about how high to make them. I reasoned that the thing runs OK without them, so I was just trying to augment the flow, and these transfers are narrower than earlier versions anyway. Plus, I did not want to shorten the transfer length, although that was just on a hunch as I have no good reason for that yet.
I only had time to fire it up and cut up a small walnut branch. It actually felt noticeably snappier, and I'm looking forward to trying it out in some real wood.
bikemike
loud pipes save lives
Ok ur gunna hate this then. I think you still can go higher with the skirt for transfer. It loss more opened up now but when you have the bearing saddle there in view nearing bdc it still looks a bit tight. Jmo the simple odd chit with these small cheep engines can really change the way they run and respond. Looking forward to a vid
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