Register

If this is your first visit, please click the Sign Up now button to begin the process of creating your account so you can begin posting on our forums! The Sign Up process will only take up about a minute of two of your time.

Page 1 of 14 12311 ... LastLast
Results 1 to 25 of 348

  1. #1

    Join Date
    Jan 2005
    Location
    San Antonio, TX
    Posts
    1,402

    Who is converting Toro trimmers?

    Hello,
    I got around to stripping down my new Toro 25cc powerhead that I got off Ebay. It looks a lot like Echo/Koritz engines. Trimming the flange will be a pice of cake, since it is heavily vented. Very nice two ring engine. The timing is retarded like many Weedeater fleatherlite. Exhust 65 degrees,Tranfers 51degrees,Intake 60 degrees. It looks like the ignition timing is retarded also. I am attaching some pictures of the raw engine. Don't be afraid to jump in with you two cents.

    Thanks, Dave
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Mk25153.jpg 
Views:	17 
Size:	56.5 KB 
ID:	298590   Click image for larger version. 

Name:	Lj22011.jpg 
Views:	13 
Size:	57.4 KB 
ID:	298591   Click image for larger version. 

Name:	Lj22357.jpg 
Views:	14 
Size:	59.2 KB 
ID:	298592   Click image for larger version. 

Name:	Vt57420.jpg 
Views:	22 
Size:	55.1 KB 
ID:	298593  
    Every day above ground is a good day.

  2. #2

    Join Date
    Jun 2005
    Location
    Mansfield, TX
    Posts
    215
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    Dave,

    I have been looking at the Toro conversion done here...

    http://www.scottellingson.com/store_007.htm

    He quoted me $155 plus shipping. I sure would be interested your results !

    CJ

  3. #3

    Join Date
    Dec 2003
    Location
    kissimmee, FL,
    Posts
    85
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    That Toro looks a lot like a Kawasaki 26.3 cc engine that I have converted.The intake on your looks a lot like the intake on mine, and the casting on the front of your crankcase looks a lot like mine before I cut my crankcase. I found that the heat dam from a Stihl 25cc engine would work on the Kawasaki. I used the stock muffler but I modified it a little bit. There is a picture of my Kawasaki in this thread.

    http://www.rcuniverse.com/forum/m_25...tm.htm#2525185


  4. #4

    Join Date
    Jan 2005
    Location
    San Antonio, TX
    Posts
    1,402

    RE: Who is converting Toro trimmers?

    Hi,
    I have a new Makita 24.5cc from a RC250 trimmer, a new Toro 25.4cc trimmer, a used Mantix 21cc cultivator and all of them look like they came from the same designer. They all have the same basic design. I think that Koiritz makes them all. Does your Kawasaki have a two or three magnet flywheel? When the engine is at top dead center (TDC) where are the magnets positioned. With most o0f my American engines, the two magnets are centered under the two poles of the coil. This is true with Homelite 25,33 Ryobi 31,26 Echo 44cc which is a three magnet wheel. The trailing magnet is uncovered on the Echo 44cc saw engine. With the Japanese engines the magnets are centered on some and others lead or trail. I need to rig a degree wheelsetup so that I can use my timing light. These differences in timing are probably emissions related.

    Dave
    Every day above ground is a good day.

  5. #5

    Join Date
    Jan 2004
    Location
    Blairsville , PA
    Posts
    124
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    I was wondering how suitable these are and looked here. Thanks for posting the pictures. I see some good points, the muffler bolts on instead of springs or wire, like you said trimming should be relatively easy, it has a rear bearing, a plus, and it looks like a built in mount for RC. All in all these look like they are better suited than most. I also like the way the flywheel is backwards like a Weedeater brand. Your pictures helped me, thanks again.

  6. #6

    RE: Who is converting Toro trimmers?

    Hi all, I am Scott Ellingson. I have converted many engines. Over 50 of different sizes and models. For a 25cc the Toro is the closest I have come to a G26. Actually if done right it will be as good or a little better. Zenoah claims 8900 on an APC 16x8. My test Toro is up to just over 8600 on that prop with a gallon of fuel ran through it. The engines I convert are a little different than the one you have. Mine have the rubber hoses running to the transfer ports. I like them because it allows me to mill out the transfer ports, then weld shut the covers and reinstall them. I then mill out the exahust and intake to a much larger size for better flow. The one thing i still want to try is moving the flywheel a few degrees to advance the timing a little. It will make it harder to hand start but should pick up power.
    If you want a good quality 25cc to convert the Toro is it. I have done Poulan 25, Homelite 25, amd Mac 28cc's. The toro woops butt[:@] on all of them.
    There is no replacement for displacement....you can allways throttle back!

  7. #7

    Join Date
    Jan 2005
    Location
    San Antonio, TX
    Posts
    1,402

    RE: Who is converting Toro trimmers?

    Hello,
    Here are some more pictures of the Toro 25cc witj out hoses on the transfer area. Also a modified manifold to accomadate a 11mm carb without a pulse hose.

    Dave
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Om34426.jpg 
Views:	15 
Size:	54.8 KB 
ID:	307915   Click image for larger version. 

Name:	Ql34865.jpg 
Views:	14 
Size:	54.9 KB 
ID:	307916   Click image for larger version. 

Name:	Di99585.jpg 
Views:	22 
Size:	39.6 KB 
ID:	307917   Click image for larger version. 

Name:	Xr45896.jpg 
Views:	13 
Size:	61.8 KB 
ID:	307918   Click image for larger version. 

Name:	Oz31364.jpg 
Views:	19 
Size:	68.0 KB 
ID:	307919  

    Every day above ground is a good day.

  8. #8

    Join Date
    Jan 2004
    Location
    Blairsville , PA
    Posts
    124
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    Hi, it is going to be hard to keep up with all that is going on here now, I know that none of us are going to puposely ignore any one. I just received the 8mm x 1 taps I ordered so now I can make a couple of prop hubs. I have an engine like you describe, designed with a 2 bbl carburetor and an engine like Dave Wallace's, designed with a single bbl carburetor. I kind of like these carbs, IF they will perform. No one has mentioned the original carbs that I have seen. I will "open ports" also if needed. I have mine cleaned up, the back plate mounts made, and when I get the hubs machined, I am going to test them against each other, with no porting and the original carbs for a baseline(s) of operation for these Toros. It is good to hear the report on RPMs that you are getting and I agree they are well made engines. They are nice and light also as you say. It looks like they have a forged conn rod besides the dual reasonably sized front and rear bearings. The 2 bbl version also has a 3/8" spark plug (3/8 x 24 threads, I think, they are fine threads, but I really didn't think to check until now. Normally you find a 7/16" thread on trimmer spark plugs. Oh yes, the reason I want to run them with the original carbs is because I ran them as a trimmer powerhead, as received, and the throttle response was excellent, nice and lively, but of course there was no load. The Toro carbs I discussed are not like a Walbro or a ZAMA and in fact are somewhat like the rotary barrel RC engine carbs. The idle adjustment that is more important to us than a weedeater user is accomplished by a mechanical limit stop of the rotation of the rotary barrel, cylinder, or whatever it is actually called. The single barreled carb is somewhat simpler, simply by having only one bore through the carb that the rotary part opens and closes like a RC carb. The bore on the single bbl does seem small and could be restrictive. The 2 bores of the 2 bbl carb also seem small. In spite of this I will try them and might work on them if necessary because I figure if they won't work as is, there is not much of a gamble in possibly ruining them. I have already figured how to lighten the spring return so a servo would not have to fight a fairly strong return spring. Some carbs are a challenge in figuring out a linkage for them that will be good and reliable. They all seem to be different in some way so expect to put on your thinking cap for this part of any conversion. So, has anyone tried a converted engine with the original Toro carb and what were the results? A new carb and the cost for it to get the most performance out of any engine is likely to be the same for these Toros as with most other engines I suspect. You at least need to have a 2 needle carb for RC. Most trimmers I see now have a single needle carb.)

  9. #9

    Join Date
    Jan 2004
    Location
    Blairsville , PA
    Posts
    124
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    Scott, I wonder if you have seen a single bbl Toro engine? They have a bigger and different intake port but the exhaust port seems to be about the same as the 2 bbl version. Since you have good results by porting, I will look closer at the ports of both. As far as trying to alter the timing a few degrees, we won't know if it is worth the effort without trying. Have you figured out how to do it with doing any damage to the basic engine? I have a suggestion you might consider. How about rounding out the mounting holes in the magneto coil and then make some bushings to fit with off center holes, which would give an excentric adjustment ability. (Like adjusting the camber on some cars front ends.) Of course, this will probably be a trial and error deal. A washer on top (maybe the bottom also) would then be needed to tighen it all down. One other point to add: Getting more power on the top end by changing the timing might negatively change the engines idling ability. What do you think? Be conservative at first? ( I like a good idle without the engine quiting because I have been in enough trees.)

  10. #10
    Ralphbf's Avatar
    Join Date
    Mar 2004
    Location
    Woodland, CA
    Posts
    1,450
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    In my Hot Rod days we used an off set key to change the cam timing
    Ralph

  11. #11

    RE: Who is converting Toro trimmers?

    I actually have thought of changing the timing. I was actually going to remove the key on the flywheel and tighten it down in slightly different locations to try it. If I find a good result I will widen the key-way and use sleeve retainer on the flywheel. Only problem is it will never come off I have not had time to do many things with porting the Toro. I have got it to the point I am now and it should (after break in) put out the same as a G26 at less weight. 3lbs 7oz ready to fly. I have been to busy building engines I have sold to do much more. I make all my own parts so it takes allot of my extra time. This winter when thing slow down I am going to blueprint the engine and see where all the ports are timed. That will help to figure out the best combo for even more power. Reliability is just as important as power so I am not sure how much more can be squeezed out of the engine. I agree a reliable idle is a major concern. My test engine never dead sticks now. It has around 2 gallons through it and it runs from takeoff to landing perfectly. The biggest thing is tuning. Many people are not that good at tuning a gas engine. Much different than glow but once you figure it out it is easy. I am putting a 25 in a 110!QUOT! Sig Rascal right now. It will be a great combo. Our test engine is getting moved from an 18lb biplane to an 11lb 1/4 scale space walker. It will be a better plane for the engine. The biplane is a pile of crap. So warped up it takes 3/8 trim on the ailerons to keep it level. Like pulling a box through the air.
    To answer your question about the single bbl toro engine, No I have not done one. I ordered 40 of the engines and all were the 2 bbl. I got lucky, I machined a 2bbl model for a guy a week ago. It looked the same but was cast different. There was far less aluminum around the intake and exhaust. Very little room to machine. That model is no good for conversion. At least it will not put out the same power.
    There is no replacement for displacement....you can allways throttle back!

  12. #12
    Ralphbf's Avatar
    Join Date
    Mar 2004
    Location
    Woodland, CA
    Posts
    1,450
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    So your saying the 1 barrel version is the one to convert.

    I've been looking for the 2 barrle version.
    Ralph

  13. #13

    RE: Who is converting Toro trimmers?

    I am sure not saying that. I have only done the 2bbl version. I like them because of the ablity to increase the size of the transfer ports. The results I have goten are very good. A good running, light, and powerful engine. I think either convert well. I would have to see some numbers on the 1bbl version to decide which is best. My conversions get 7800 to 8000 rpm on an APC 16x8 prop. They will pick up around 1000 rpm or more after break-in it complete. That will take 4-5 gallons of fuel on non synthetic oil. Synthetic is not good until break-in is complete.
    There is no replacement for displacement....you can allways throttle back!

  14. #14

    Join Date
    Jan 2004
    Location
    Blairsville , PA
    Posts
    124
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    About my suggestion to change the timing, I was thinking about another magneto with slots. I looked at the Toro just now, my suggestion is not that good for this engine, it would take some engineering to change the timing and who knows if the time would be well spent. I tend to be satisfied with 7500 to 8000 RPMs out of 25cc. I just read your comments about the 2 bbl version with not much metal around the ports to enlarge them. I think this is what I have and I was wondering when I read you saying you enlarged the ports a lot. That is now cleared up. I haven't had a whole lot of time either up to now to work on these Toros. There must be several versions of these engines, maybe some we haven't seen yet. I took the rear cover off of the rear intake, you know the little rascal where the rear rubber tube connects, to be absolutely clear. There is a Reed valve in there. Is that familiar? I didn't check the front one yet, but I expect it will have one also. With these particular engines, lets call them the "2 bbl light castings", I would think the exhaust ports could be enlarged a bit and then an adapter intake should be possible to use a bigger bore 2 needle Walbro or ZAMA carb with an adapter intake spacer that makes use of the rubber tubes to the front and rear intake ports. I will try something along this line of thinking when I get to it. These engines have turned into a tangent hobby. I have two RC airplanes, glo versions, and I haven't flown either one in a long time. You mentioned a 28cc McCulloch, the first engine I converted is a 32cc Mac. The ports are decent sized as is, I used a 5/8" Walbro and get close to 8000 RPMs with a 20-6 prop. Of course I added a 5/8" pipe to the muffler also. I like the 32cc Macs, I have a couple more of them, but they are around 5 lbs.

  15. #15

    RE: Who is converting Toro trimmers?

    The best way i have found to deal with the reed valves is to close the holes and remove them. Do not use the rubber hoses at all. It would be a bear to make an intake to utilize them. I make new intakes after I increase the intake size. I also turn the carb the correct way for RC use. I then run a remote pulse line to the carb. It is the only way to do it if you turn the carb. 1 intake bolt lines up with the pulse hole on the carb so no way to run a channel. A good way to tell if you have the good 2bbl engine is the color. The thin one is very bright silver. Also if you look on the back you will see 3 gussets in a triangular pattern. They look as if they could be drilled and tapped for somthing. If your fins are even all the way accross, you have the good engine. If there is a circular dip in the middle of the triangle pattern then it is the thin one. If it is the thicker one it can be made to do well over 8000 rpm when broke in. If the thin I think 8000 may be the max. I run an 11mm Walbro twin needle carb on my conversions. That and an aluminum pits style muffler. A velocity stack will pick up 300 or so RPM on this engine and actually the stock muffler only reduced the RPM by a couple hundered but was very quiet. Strange I thought.
    There is no replacement for displacement....you can allways throttle back!

  16. #16

    Join Date
    Jan 2004
    Location
    Blairsville , PA
    Posts
    124
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    Scott, It remains to be seen with modifying some of these 2 bbl Toros. If there is not enough metal around the main intake port to open it sufficently?, maybe the only way to get enough power is to find a method to use the front and rear Reed controlled ports? I haven't really looked at this system closely. I haven't pulled a cylinder completely off yet. It might be possible to cut down the height of the original carb spacer/intake maniflold and make an adapter to center a single bbl Walbro on it? I don't see the need to turn the original plastic manifold yet, I will study it more. These engines are light enough to consider them for twins. The pull starter will add about 5 ounces and could probably be retained if a modeler wanted to do that. One other point, obviously a lot of money was spent on research and development to design these engines. The basic mechanical design is very sound and a lot of the money was no doubt spent on emissions. A lot of the small 2 cycle engine companys now seem to be concentrating on 4 cycle designs, for emissions, so some 2 cycle bargains, like these Toros, are showing up as surplus.

  17. #17
    ETRNL's Avatar
    Join Date
    Apr 2005
    Location
    layton, UT
    Posts
    238
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    sorry to jump in on your guys conversation but is the same engine your talkin bout????

    [link]http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7707022525&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1[/link]
    ETRNL KNIGHT
    \"If u can read this, thank a teacher, If u can read this in english, Thank a Vet\"

  18. #18
    Ralphbf's Avatar
    Join Date
    Mar 2004
    Location
    Woodland, CA
    Posts
    1,450
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    Maybe, there are two versions, a one and a two barrel.

    I'm not sure which one Scott is converting, and the guy selling these doesn't know which one he has.
    Ralph

  19. #19

    Join Date
    Jan 2005
    Location
    San Antonio, TX
    Posts
    1,402

    RE: Who is converting Toro trimmers?

    Hello,
    The engine that Junkman is selling is the piston port engine with a clutch. The engines Scott is converting are the so called two barrel version. They are the same except for the cylinders. The two barrel version has reed valves built in to the transfer ports. The one on ebay would be a good engine for a MT.

    Dave
    Every day above ground is a good day.

  20. #20

    RE: Who is converting Toro trimmers?

    You will have to ask Junkman which he is sending. He doesn't know which he has unless he looks. He has both the 1 and 2 bbl versions. All the engines I have are from him. He is a very nice guy to deal with. Buy 40 at a crack and he gives an even better deal
    I just test ran 2 tonight that i sold. These i put a 9/16 id exahust pipe on instead of a 1/2 id. Both turned an APC 16x8 at 8100 rpm. That is very good. I use a laser tach accurate to .05%. All of the other ones I converted started around 7800 RPM. The best part is they will pick up 800 to 1000 rpm when broke in. If that holds true they should do that prop at 8900 to 9100 rpm. If that ain't a G26 I don't know what is. They make a Homelite look lika a terd
    There is no replacement for displacement....you can allways throttle back!

  21. #21

    Join Date
    Jan 2005
    Location
    San Antonio, TX
    Posts
    1,402

    RE: Who is converting Toro trimmers?

    Hi Scott,
    The one I got from Junkman was the piston port type. It has the small transfers without much beef around them. I wrongly assumed that that was all he had. Your engines with the milled out transfers are the best choice.

    Dave
    Every day above ground is a good day.

  22. #22

    RE: Who is converting Toro trimmers?

    I think they may be all worth a try. When I mill them the ports are still no bigger than a Homey or Poulan 25cc. There is just somthing about the engine that is makes power. I suppose the twin ring helps. Plus they are ballanced so well. Very little vibration at all. All the toro's should make a good conversion. Some types may have a little more potential but I think they will all be good. I would like to see some numbers on an engine like yours. It may suprise you.
    There is no replacement for displacement....you can allways throttle back!

  23. #23

    Join Date
    Jan 2004
    Location
    Blairsville , PA
    Posts
    124
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    I made a couple of prop hubs and ran a single bbl and a 2 bbl Toro, both with a Master Airscrew Classic prop. I used this same prop to test the 21 and 25cc engines I have done. The 2 bbl toro gave 7300 to 7400 RPM. I use a ACE Tachmaster that I modified and added 3 extra scales to along with a 2 or 3 blade selector switch. As long as the Sun is out, I have a 5k, 10k, 15k, 20k, and the 25k RPM range. I still have the article to do this somewhere, if anyone is interested in the modifications. OK so the 2 bbl put out around 7300 to 7500 RPM and I could see it was not going to go much higher so I concentrated on adjusting the idle, THE ONLY ADJUSTMENT, and it would idle nicely around 2200 RPM or so. These are still new engines with very little time. The throttle response is very quick. The single bbl engine idled great, but sagged above 3/4 throttle and I was running out of time today for this. It was obvious that the single bbl carb has problems. I will take it apart out of curiosity to see if I can find the problem. The way these carbs are designed, they are Walbros by the way, it is very difficult to "bore" them bigger. There is wire that moves into out of a plastic tube, when the barrel rotates. The wire doesn't look like it can easily be removed to work on the bbl. I would try this if possible because of the excellent throttle response. I now am going to make a carb spacer adapter and try a 13mm Zama (9/16") to replace the single bbl. I haven't given up on the 2bbl engine. I am going to look at the ports on both engines also to see if they can be opened. I think an aluminum plate adapter is possible for the existing 2bbl carb spacer to adapt a 13mm carb to it also. I am going to modify the existing 2 bbl carb spacer/manifold also. I think the main intake port can be opened some and I am going to leave the secondary Reed ports in place and in operation to see how this works. I think there could be some potential with using the Reed ports, after all there are already there, and before I defeat them, I want to satisfy my curiosity. One other point about these engines, I think a aluminum plate mount bolted to the rear of the engine is well worth the trouble. 1/8" is thick enough, and this gives you a larger footprint for mounting along with strengthing the rear of the case, in my opinion, for not that much weight. I use a 3" x 4" plate with the engine centered. I counter sink for the 10-32 mounting screws, but not all the way flush. If you leave them a bit high, your firewall will keep the screws from backing out. Another small point is that the muffler on the engine can work out very well for a side mounted engine. The screen "spark arrestor" (I guess that is what it is for) is easy to pry off and then an exhaust hose could be used. I tested with the original mufflers and they are pretty quiet. When you examine them, it doesn't look as though they would restrict the engine too much and they are not overly heavy. Until the next chapter of the Toro saga.

  24. #24

    Join Date
    Jan 2005
    Location
    San Antonio, TX
    Posts
    1,402

    RE: Who is converting Toro trimmers?

    Hi,
    Could you post some pictures of those reed valves?

    Dave
    Every day above ground is a good day.

  25. #25

    Join Date
    Jan 2004
    Location
    Blairsville , PA
    Posts
    124
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Who is converting Toro trimmers?

    Hi Dave, I intend to post some pictures when I figure out how. My digital camera and it's software is part of the problem. I got too many irons in the fire. I also had to put a new hard drive in and lost a bunch of stuff on the old drive. You know, everything happens at once. I have done some more testing, I used a new 14mm carb on a single bbl Toro with a new carb manifold I made to match, the results were not spectacular, but the way it was running I now think the magneto must be defective. It was not running steady, I thought it might be too much carb, but this is the engine that ran the same way with the original carb. It still turned 7500 RPMs with a 16-8 and I think it will do much better. This is the same ZAMA carb as the one that gave me close to 8k with the 25cc Weedeater, so I will resume testing with another magneto. I plan on posting photos also, I took some photos already.


Page 1 of 14 12311 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
All times are GMT -6. The time now is 07:05 PM.

SEO by vBSEO 3.6.1 ©2011, Crawlability, Inc.