TBS
I have chainsaws and chainsaw accessories.
Ever so slight which is common on a lot of zenoah designed cylinders.
I killed my old ryobi...kind of.
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Ever so slight which is common on a lot of zenoah designed cylinders.
nenicu
ArboristSite Operative
For general information: the strato Ryobi's were made in 40 cc and 44 cc [sold in Europe]. They were sold as Homelite also in both 40 and 44 cc. I'v had both Ryobi variants and i now have a 44 cc Homelite. The 40 cc Ryobi was Zenoah Komatsu ,the 44 cc[Ryobi and Homelite] built with chinese cylinders.
Chris-PA
Where the Wild Things Are
This thread inspired me to port my Ryobi!
Previously I had pulled the base gasket, matched the lower transfers and modded the muffler, but the porting was unchanged. It ran nicely, but with a 132deg exhaust duration I always wanted to get a bit more from it. Today it was warmer but raining so I pulled the cylinder. The exhaust was raised to 142deg duration and widened to about 55%, and the transfers were raised to maintain 15deg blowdown. I think anyway, as I have not put it back on to take final measurements. I was shooting for 60% exhaust width but it was awkward getting the dremel in there to that width, so I stopped a bit shy of my marks. It's quite a pain raising the transfers on these even with the removable covers.
Previously I had pulled the base gasket, matched the lower transfers and modded the muffler, but the porting was unchanged. It ran nicely, but with a 132deg exhaust duration I always wanted to get a bit more from it. Today it was warmer but raining so I pulled the cylinder. The exhaust was raised to 142deg duration and widened to about 55%, and the transfers were raised to maintain 15deg blowdown. I think anyway, as I have not put it back on to take final measurements. I was shooting for 60% exhaust width but it was awkward getting the dremel in there to that width, so I stopped a bit shy of my marks. It's quite a pain raising the transfers on these even with the removable covers.
TBS
I have chainsaws and chainsaw accessories.
Now I may have to port mine.
bikemike
loud pipes save lives
Beforeand after vids if possible plz
Chris-PA
Where the Wild Things Are
I have a Craftsman yellow GZ4000 that I did the same things to (base gasket, lower transfer match, muffler mod), and my Jenn Feng McCulloch MS4018 that I raised the exhaust port, transfers and also increased the strato intake duration. So this one will be in the middle.
I'm working on a mod to the Jenn Feng air valve, as I'm having trouble with shaft wear on the phenolic housing. There is a nice seal on one side, but not on the other and the phenolic housing wears at the lever end. Then the idle gets inconsistent. The design of the Zenoah valve is the same in that regard. I wanted to bore it out and put in a bearing and seal, but there is not enough material on the housing for that. Now I'm just looking to make a bushing/sleeve.
I'm working on a mod to the Jenn Feng air valve, as I'm having trouble with shaft wear on the phenolic housing. There is a nice seal on one side, but not on the other and the phenolic housing wears at the lever end. Then the idle gets inconsistent. The design of the Zenoah valve is the same in that regard. I wanted to bore it out and put in a bearing and seal, but there is not enough material on the housing for that. Now I'm just looking to make a bushing/sleeve.
bikemike
loud pipes save lives
Remove the shaft and use a dremel to hog out just a little bit of the housing to fit a oring in as a seal/bushings
Chris-PA
Where the Wild Things Are
It's wallowed out too much for that - the shaft moves too much. I 3D printed a drill guide that fits in the housing, but when I make a bushing I'll print another with a larger ID to match the bushing. I may do an o-ring, but I don't want to add too much friction, and after all carbs work OK without them. But that won't effect this saw anyway as its air valve is good yet.
I had wanted to get the saw back together today as it was 55F during the day, but going down to 16 tonight. Unfortunately the power went out when the front came through so I ran out of time. Now it's gonna be too cold for a bit. Hopefully I'll get it finished between Christmas and New Years.
Chris-PA
Where the Wild Things Are
I put the cylinder back on, sealed it up and measured the timing - and I missed. 
I was shooting for an exhaust duration of 142, which I hit, and a transfer duration of 114, which I did not. I must have measured poorly and ended up with a transfer duration of 120. 6deg of blowdown wasn't going to work well. So I had to increase the exhaust duration to 150, which should run well, but it was not the plan. The exhaust width is at 57%. The blowdown is at 15 which is where it started (stratos can stand a shorter blowdown than normal).
The cylinder is back on again and hopefully I'll get the rest back together so I can run it Friday.
I was shooting for an exhaust duration of 142, which I hit, and a transfer duration of 114, which I did not. I must have measured poorly and ended up with a transfer duration of 120. 6deg of blowdown wasn't going to work well. So I had to increase the exhaust duration to 150, which should run well, but it was not the plan. The exhaust width is at 57%. The blowdown is at 15 which is where it started (stratos can stand a shorter blowdown than normal). The cylinder is back on again and hopefully I'll get the rest back together so I can run it Friday.
Chris-PA
Where the Wild Things Are
It worked out quite nicely:
In the first clip it's running around 11k, but I was having trouble tuning it due to a leaky check valve. Yet another crap ZAMA C1Q. It was not all that big a leak, but enough to make tuning inconsistent, especially the L. So I put another carb on it with a check valve that seems to seal better and took the second clip, but in a different piece of wood since I had bucked the other one up. Here it's running 12k. The chain is just Oregon 91PX.
I did use it to noodle full bar and it ran great. I'll have to find a bigger piece of wood to buck make it work more, but I'm happy with the way it runs.
In the first clip it's running around 11k, but I was having trouble tuning it due to a leaky check valve. Yet another crap ZAMA C1Q. It was not all that big a leak, but enough to make tuning inconsistent, especially the L. So I put another carb on it with a check valve that seems to seal better and took the second clip, but in a different piece of wood since I had bucked the other one up. Here it's running 12k. The chain is just Oregon 91PX.
I did use it to noodle full bar and it ran great. I'll have to find a bigger piece of wood to buck make it work more, but I'm happy with the way it runs.
TBS
I have chainsaws and chainsaw accessories.
So I'm not the only one that had issues with that particular carburetor!lol. Your saw cuts nicely!
Chris-PA
Where the Wild Things Are
Thanks! I really don't like C1Q's
TBS
I have chainsaws and chainsaw accessories.
I bought a 40cc from surpass to go with the 56cc and it is a nice piece. I'll load a few pictures later.
TBS
I have chainsaws and chainsaw accessories.
Actually worked on the ryobi today. Did a little exhaust porting removing the huge lip in the port. Should have it back ready to run tonight with the tanaka.
I also finally ran the surpass 56cc in 18inch pine and it can throw chips
, the only issue was the fuel filter hangs up by the cap but it's a simple fix.
I also finally ran the surpass 56cc in 18inch pine and it can throw chips
, the only issue was the fuel filter hangs up by the cap but it's a simple fix.
Ryobi has also the 35cc strato cilinder. Also made by Zenoah/Komatsu.
Pics of mine (whitout the cilinder shaped strato venturi. Waiting on my order...)
TBS
I have chainsaws and chainsaw accessories.
I got it back together but ran into problems, I snapped a cylinder bolt, and need a card kit. I also got the tanaka more or less together but the chain tensioner was broke. The ryobi is coming apart again.
I took the 56cc out for noodle making and it kept me happy ripping up 20x24 rounds, much better saw than a husqy 445.
Glad to hear you guys are still playing with the Ryobis. Some of the parts can be bought online from Ardisam, makers of the earthquake clone. I use the Tiger bars like the one Chris had in his video. I think the saws pull the 16 inch bar much better than the 18 inch bar the saws come with, plus a few years back those bars, along with a chain were going for $13, so I bought 6 of them. Very recently there was a good deal on 14 inch Raisman bars, so I got a few of those to try, too. Haven't had them in wood yet, except on a yellow Craftsmen "professional" version that needs the limiter caps pulled.
I have had problems with the C1Q carbs, too. Some of them are fine and some seem to be very erratic, no matter what you do. There is a chinese carb on eBay right now that fits the 38cc earthquake and is going for something like $13, but it isn't the strato version on the Redmax/Ryobi. I've thought about using the strato linkage from a bad C1Q in the chinese carb as a cheap fix to the carb problem, but Chris says the venturi size on the chinese carb is too big. Not much to lose for $13, though.
If anybody needs a new air filter for these saws, or some of the other Redmaxes, I may have a good deal for you. I bought a box of a dozen filters for them awhile back - most are for the Redmax GX4000/ryobi 10532, but some are for other Redmaxes.
I have had problems with the C1Q carbs, too. Some of them are fine and some seem to be very erratic, no matter what you do. There is a chinese carb on eBay right now that fits the 38cc earthquake and is going for something like $13, but it isn't the strato version on the Redmax/Ryobi. I've thought about using the strato linkage from a bad C1Q in the chinese carb as a cheap fix to the carb problem, but Chris says the venturi size on the chinese carb is too big. Not much to lose for $13, though.
If anybody needs a new air filter for these saws, or some of the other Redmaxes, I may have a good deal for you. I bought a box of a dozen filters for them awhile back - most are for the Redmax GX4000/ryobi 10532, but some are for other Redmaxes.
Chris-PA
Where the Wild Things Are
Well....... You got me thinking about that and I was going to post a reply to your message, but I'll just post it here. The carbs on these are little, like 24/64". That's because much of the air flows through the air valve, not the carb. But the 28/64" carbs are not that much bigger, and I was just contemplating giving it a try on a ported 40cc one I've been playing with. So I agree it might be worth the experiment. I have some carbs I can swap the shafts on.
