Going case inducted too!!!

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Ron344

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Oct 13, 2012
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Centering the reed block shouldn't be a problem it's only 1 1/4 inch center to center. lots of room for that. I figure I have all winter to work on this motor and right now it's too cold to do anything else. The only problem is I'm burning a lot of propane to heat the garage. Anyway,you should start working on your motor.
 

Davezilla

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Mar 15, 2014
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Yup... I need to start on mkine again soon... Went to take mine to the store this morning and the clutch was slipping badly so needless to say, no ride this morning.

I've been saving used brake pads that are the same thickness as the clutch pads in our engines so I'm planning on cutting out some new pads from the semi metallic ceramic pads I've been collecting. I'm also looking at other ways to improve the clutch's holding ability but hopefully this pad material will hold better than the red hard rubber or cut up tire looking clutch pads these things come with. I guess I'll soon find out since it's gonna need them before I can ride it again...
 

Ron344

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Oct 13, 2012
209
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colorado
Davezilla, I have never had the clutch slip because of the pads. I have had problems with flower nut stripping out that's why I made my own flower nut. I posted a picture of it not too far back on this thread. I might have to rethink the way I bolted that plate on the case, you were right there might not be enough room to center it on the case. Oh well, nothing ventured nothing gained.
Your idea for the clutch pad sounds interesting you'll have to show me when you make them. There are a lot of little improvements you can make to these motors. I think that's why I like working on them.
 

Ron344

Member
Oct 13, 2012
209
2
18
colorado
I got some more work done on the motor this weekend. Friday I got the reed block in the mail So I started working on bolting to the case. It was no easy project it took most of the day. I end up not putting davcon on it, it's just screwed down. Then I thought I would make a top for reed block I'm not sure how this is going to work yet but I like the looks of it. There is not much room to put the carburetor on so it will have to go out the side of the bike.
Now I will have to order some more parts before I can do too much more.
 

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MotorBicycleRacing

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I got some more work done on the motor this weekend. Friday I got the reed block in the mail So I started working on bolting to the case.

Then I thought I would make a top for reed block I'm not sure how this is going to work yet but I like the looks of it. There is not much room to put the carburetor on so it will have to go out the side of the bike.
Why not use the carb adapter plate that comes with your Arrow Motorized Cycles reed block?

 

Ron344

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Oct 13, 2012
209
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The reed block kit that I got goes on the cylinder not the case, so the one that came with it would have to be changed anyway. Anyway you look at it I would have to make something. That's why I started out this way I think I have more option when I decide what size carburetor I'm going to use. I can also grind out the inside the way I want for better flow. I'm not going to do any more until I get the carburetor I decide on. I originally was going to put fins like the head has on top, but can't do that ether until I get the carb.
 

Theon

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Jan 20, 2014
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Down draft Walbro from a Chainsaw, bolted to the top of your box would look nice.
But please tell me your not going to use an angle fire head.
 
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Ron344

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Oct 13, 2012
209
2
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colorado
Hey Theon, I was thinking of a walbro carb. or a tilotson I'm not sure what size I would need? I'm not sure if I have the clearance to put a different head on it, but I will check into that. This head had a lot of work done to it with about 160 compression. It ran real good. I do have another billet head on my other bike I could use. Also Fred makes an angle fire head.
 

Theon

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Jan 20, 2014
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The angle fire has a few disadvantages, I guess it may depend on how hot it gets there, but here, even a fairly mild engine will run hot with one. Also center fire is much better for an even burn especially as the comp ratio goes up.
The 21/19mm walbro style carbs are used on most big chainsaws, and usually have a built in choke butterfly which is handy, as the smaller walbros not necessarily.
That sized carb may be a little overkill, but bigger is good.
 

Davezilla

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Mar 15, 2014
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I was thinking the same thing, a decent sized walbro/tillotson could bolt directly to the block either to the top or the side depending on frame clearance, I think a down draft around 19 to 21mm would feed it just fine. It would be real easy to drill and tap the bolt holes into that block then drill and bore the intake hole for a down draft setup, side draft may be a bit tricky but not impossible on that block you made to bore an intake hole thrum the side without compromising air flow.
Either way, cant wait to see what you decide to do....

I got another bike coming to me Tuesday so I'll be pulling my other engine parts out and getting ready to do the conversion soon.
 

Ron344

Member
Oct 13, 2012
209
2
18
colorado
I was thinking of a carburetor between 18 and 22mm so I might try the 21mm warbro it sound like would work pretty good. Down draft would be nice if I have the room. Thanks for the suggestions.
I can't wait to see you work on yours Davezilla.
 

Davezilla

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Mar 15, 2014
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Hopefully this bike I'm getting has a nice frame, so far all I know about it is it has disc brakes, but I got a welder,plasma cutter,and a lot of steel tubing in the shop so I could do some cutting and modifying if needed...

With my clutch problem, got that fixed today but no more centrifugal until I can fix it, the gear is only pressed onto the drum so that's what came loose and was spinning freely so nothing goes to the wheel.... I'm thinking that brazing it back on should be strong enough, but for now I just set it back up as a manual clutch so I can keep riding it.

Like I mentioned, depending on what frame type this one I'm getting is, I may be building up my next build real soon but will be able to take my time on it since I already got a fast and reliable one to ride during the buildup.... since I do all my work at the shop now I may be limited to a fee hours a week to work it but should have something nice by the time the weather gets better...
 

Davezilla

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Mar 15, 2014
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The walbro and Tilly Carbs are nice too because they can be tuned externally so dialing them in is fast and easy.... the 21mm should work just fine with your setup too. I got a 19mm Tilly for my other engine too.
 

Ron344

Member
Oct 13, 2012
209
2
18
colorado
I went to a small engine shop today to ask about some different walbro carburetors and the guy ended up giving me a 22mm walbro. That worked out real nice. I'm thinking I might use the steel plate that came with the reed block it will give me more room for an air filter. I will have to do some fabrication work to make it work. I will probably need to make a piece to raise it up a little too.
 

Davezilla

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Mar 15, 2014
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That size will work well and the beauty of these floatless carbs is that they don't necessarily need to be oriented perfectly level to work so if you need to set it up as a down draft or even as a 45 degree draft it'll work the same, you could just make a flat plate to adapt the carb directly to the reed box if there's enough frame clearance. Technically that would give the best airflow since there are no bends from the carb into the reed block if you got the room...
 

Ron344

Member
Oct 13, 2012
209
2
18
colorado
Your right about the carb you can put it in any position you want, that's the nicest part. I got more work done today. I made the carb plate and a spacer for it. Next I might start on the air cleaner.
 

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Flyman

Member
Nov 28, 2014
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Vian Oklahoma
I,m running a 19mm Walbro.Just make sure your seals don't leak.The pumper
must have a sealed crankcase to work.If not they will lean out & stick the piston.

Fly
 

Ron344

Member
Oct 13, 2012
209
2
18
colorado
Fly, I have been thinking about that. I might go with the sealed bearings seeing you probably can't get better seal for these motors. The next thing I need to do is order bearings for the case and wrist pin. I haven't done it yet because I'm not sure what to get.
 

Davezilla

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Mar 15, 2014
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That's another issue and most people just plumb in a small barb from one of the transfer ports to make the pulse line. These cases do a pretty good job here, but the gravity feed is usually enough to feed the carb if the pulse line does get accidentaly disconnected. I use those small spring clamps on stuff like that because they're typically easy to install and remove as well as providing even clamping pressure all the way around the tube to prevent future air leaks and help secure the lines. You can get these in any size off ebay for cheap, and most auto parts stores have these in small assorted kits, but if one is needed that's smaller than 1/4" or 6mm they're easy to find on ebay... Cheap insurance too. Also in a pinch or if you simply can't get a hold of the smaller spring clamps, safety wire also does an excellent job.