Motorized Bicycle Engine Kit Forum  

Sponsors



Go Back   Motorized Bicycle Engine Kit Forum > Bicycle Motor > DIY Home Built Motorized Bicycle (non kit)

DIY Home Built Motorized Bicycle (non kit) Post all about your home built rides here. Weedwacker motors, lawn mower engines ect. This area is for non kit builds

Reply
 
Thread Tools Display Modes
  #51  
Old 01-31-2017, 10:37 PM
MEASURE TWICE MEASURE TWICE is offline
Motorized Bicycle Elite Member
 
Join Date: Jul 2010
Location: CA
Posts: 1,897
Default Re: Adapting Briggs Build to accept bigger engine

I took the bike out to the motorcycle OHV park. It has quite enough power for the 13:1 ratio and climbs hills great. Lot of get up and go!

No hard starting due to any of what I saw a little oil around the air filter from the breather tube. I did not take the filter out to see, but there was no more dripping.

There is a sort of a problem with starting the engine, but it is not the engine per say. The clutch grabs good too. It is when the engine is off and you pull the recoil starter, the clutch sometime still grabs a little. If you do not have the rear wheel off the ground you cannot get the engine started when it is doing this.

I found a work around before I try to repair or replace the clutch. Could be lubing some other area than just the brass bushing?

What I did to get by today was with engine off move the bike a few inches forward and then reverse and feel when it frees up. Then I stop moving the bike and start as normal.

Still this is not desired, so as soon as the next storm is gone I will look and see whats grabbing when it should not. I could think maybe the springs on the clutch could be worn. I don't think anything uses lube for the shoes as it could then get on the grabbing surface of the shoes and the bell.

Also take a look at the critters that were in the road. I was in my truck, but I had to stop. So I got a few pictures.
Attached Images
File Type: jpg CAM27118.jpg (234.1 KB, 6 views)
File Type: jpg CAM27119.jpg (215.1 KB, 9 views)
File Type: jpg cropCAM27118.jpg (149.3 KB, 8 views)

Last edited by MEASURE TWICE; 01-31-2017 at 10:40 PM.
Reply With Quote
  #52  
Old 02-04-2017, 11:59 PM
MEASURE TWICE MEASURE TWICE is offline
Motorized Bicycle Elite Member
 
Join Date: Jul 2010
Location: CA
Posts: 1,897
Default Re: Adapting Briggs Build to accept bigger engine

Found the issue with the clutch was that the bushing was gummed up with maybe the oil I put on that maybe gathered some dust. I cleaned it out with paint thinner and then oiled it up and it is smooth. Just don't know if it will be happening again soon needing cleaning. There are some groove scratches in the bushing. The springs although rusty and maybe worn are cleaned with wire brush before and are not a problem.

I got some springs from the hardware store thinking I would maybe need them, but they were the wrong size anyway. I just want to ride it some more and just put every thing back. Another time I'll bring the clutch springs to see if I can find a match, but it probably is not an issue.

Was wondering if I could get a replacement bushing sleeve of brass from the company that makes the clutch. I already contacted them and they probably either did not have any support life for such an old clutch or they forgot. The bushing may be something I will just try to find else where as well, like at the hardware store. Otherwise I saw a Max Torque 35 chain 3/4 clutch with two sets screw and a full length key way for about 32 dollars on Amazon. Free shipping.

A fiber washer broke, I will get another to replace inside the clutch. It was where I pointed to. Probably could run without it, but I'll even cut some material to the right size with a gasket cutter set I have if necessary. OSH has a lot different sizes of these fiber washers.

I really like the feel of my whole torso being pushed back from the acceleration as I twist the throttle.

This is da beast!
Attached Images
File Type: jpg CAM27310.jpg (254.9 KB, 10 views)
File Type: jpg CAM27311.jpg (337.6 KB, 8 views)
File Type: jpg CAM27312.jpg (242.2 KB, 7 views)
File Type: jpg CAM27320.jpg (297.5 KB, 8 views)
File Type: jpg CAM27316.jpg (346.0 KB, 9 views)

Last edited by MEASURE TWICE; 02-05-2017 at 12:18 AM.
Reply With Quote
  #53  
Old 02-12-2017, 12:15 AM
MEASURE TWICE MEASURE TWICE is offline
Motorized Bicycle Elite Member
 
Join Date: Jul 2010
Location: CA
Posts: 1,897
Default Re: Adapting Briggs Build to accept bigger engine

Tried the bike today after oiling the sleeve bearing and it rolls easy with the engine off and starts so easy.

I will replace the fiber washer in the clutch when I find a better supplied Hardware Store. One fiber gasket that needs just a little trimming will make a couple and have an extra for the pawl clutch in the older engines recoil starter. OSH did not have the exact size one for the clutch or the pawl clutch I replaced by scavenging one from an other recoil starter.

I have a punch set for gaskets I bought at HF for cheap. It got a but rusty, but some how the sharp cutting edges were left untouched. I'll make the pawl clutch gasket for a extra spare part. Finding a fiber gasket big enough for ID and OD, did not happen.

I did see Granger and some Ebay sellers have a oil lite, or called bronze brass sleeve bearing. From today's ride I don't think it is going to be necessary to replace with a new one, but nice to know I can get the part for the old clutch.
Reply With Quote
  #54  
Old 03-01-2017, 07:32 AM
scratchbuilder's Avatar
scratchbuilder scratchbuilder is offline
Motorized Bicycle Elite Member
 
Join Date: Jan 2015
Location: ca.
Posts: 536
Default Re: Adapting Briggs Build to accept bigger engine

Mt, didn't you add-on to your 3/4 short crank..i might have to do that..although it means going outboard with my clutch.
Reply With Quote
  #55  
Old 03-01-2017, 02:41 PM
MEASURE TWICE MEASURE TWICE is offline
Motorized Bicycle Elite Member
 
Join Date: Jul 2010
Location: CA
Posts: 1,897
Default Re: Adapting Briggs Build to accept bigger engine

Parts or parts and shipping to make the crankshaft longer to fit the clutch was not worth the cost. Buying a used Briggs would be cheaper.

Also to make longer these clamp on adapters also makes some of the added length unusable. So the total length would have extended the cover. I would have to work on the cover too. The cover is already more than I like sticking out, but it is not so uncomfortable that I would redo everything I built.

Considered this is a learning experience and another build when I can do it will take all this into account to try and have things work out best.

As you said about turning the clutch around, it will usually with most clutches not matter as far as the shoes grab.

The thing I did notice in either gears or clutches, if there is a full length key way or not, when you try to put a key on the crankshaft up next to the crankcase wall, is that the darn key way slopes upward right at the crankcase wall.

This makes a key not fit flush. It does not matter if there is enough key to do the job and you resort to shortening the key a bit. If there is not much key left though to fit, then like what I have is 1/2 inch length key. Is this enough?

I think so and I'll see.

I did something in the past to modify a key which rather than cut it shorter when presented with this problem.

I took a Dremel and carved the mirror image shape of the slope at the inboard end of the key way on the crankshaft, onto the key I made. Half of the key had a square shape and the rest was carved to a shape enabling me to use the sloped section of the key way all the way up to the crankcase wall.

I think it was Fasteddy said the reason for the carved slope shape on the Briggs crankshafts inboard end of the key way slot, is for removal of keys that might get stuck. I though could be as if you chew up a key and damage the key or the key way slot then it would be difficult to remove the key. I suspect tapping the key in the direction of the crankcase wall, the key naturally gets pushed up at that curved sloped angle. The with screwdriver and needle nose vise-grip type remove the worn key.
Reply With Quote
  #56  
Old 03-01-2017, 05:16 PM
curtisfox curtisfox is offline
Motorized Bicycle Elite Member
 
Join Date: Dec 2008
Location: minesota
Posts: 3,723
Default Re: Adapting Briggs Build to accept bigger engine

I think it was Fasteddy said the reason for the carved slope shape on the Briggs crankshafts inboard end of the key way slot, is for removal of keys that might get stuck. I though could be as if you chew up a key and damage the key or the key way slot then it would be difficult to remove the key. I suspect tapping the key in the direction of the crankcase wall, the key naturally gets pushed up at that curved sloped angle. The with screwdriver and needle nose vise-grip type remove the worn key.


I think the real reason is because they us a rotary cutter, and can only get so close with it. All do to automation,and modern machining ............Curt
Reply With Quote
  #57  
Old 03-01-2017, 05:56 PM
scratchbuilder's Avatar
scratchbuilder scratchbuilder is offline
Motorized Bicycle Elite Member
 
Join Date: Jan 2015
Location: ca.
Posts: 536
Default Re: Adapting Briggs Build to accept bigger engine

Yep..the next build I'll get everything right....wrong! I agree I've got my eye out for another engine. I'm gonna put the 3.5 crank back where it goes...maybe a belt drive. I don't want to set in on the shelf not right.
Reply With Quote
  #58  
Old 03-01-2017, 06:48 PM
curtisfox curtisfox is offline
Motorized Bicycle Elite Member
 
Join Date: Dec 2008
Location: minesota
Posts: 3,723
Default Re: Adapting Briggs Build to accept bigger engine

Can always put the clutch on a jack shaft......................Curt
Reply With Quote
  #59  
Old 03-01-2017, 09:46 PM
MEASURE TWICE MEASURE TWICE is offline
Motorized Bicycle Elite Member
 
Join Date: Jul 2010
Location: CA
Posts: 1,897
Default Re: Adapting Briggs Build to accept bigger engine

That is what I did, but lost one of the mechanical advantage of one pair sprockets small to large to gear down. Not a problem now since I found this replacement engine doing just fine at a 13:1 ratio instead of 20:1 ratio.

As far as a 1/2 inch key length I think it won't shear unless maybe hit a log, but then there is a problem as the front wheel would probably also crumble.
Reply With Quote
  #60  
Old 03-03-2017, 11:39 PM
MEASURE TWICE MEASURE TWICE is offline
Motorized Bicycle Elite Member
 
Join Date: Jul 2010
Location: CA
Posts: 1,897
Default Re: Adapting Briggs Build to accept bigger engine

My new clutch works great. There are 13 teeth on this new Max Torque clutch instead of like my older clutch with 12 teeth.

Now my Overall Ratio is 12:1 instead of 13:1 on to a 26 inch rear wheel, but still the engine handles it really well and start very easy always.

Looking forward to trail ride and explore soon.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 10:50 AM.


Sponsors

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
MotorBicycling.com