Motorized Bicycle Engine Kit Forum
Register FAQ Members List Calendar Mark Forums Read

Sponsors



Go Back   Motorized Bicycle Engine Kit Forum > Motorized Bicycle > Motorized Bicycle General Discussion

Spark knock


Discussion at Motorized Bicycle Engine Kit Forum in the Motorized Bicycle General Discussion forum. I hear a little banging around in my engine I hope it is not a bearing bounching around in there. ...
Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 05-15-2008, 10:49 AM
Master Motorized Bicycle Builder
 
Join Date: Mar 2008
Location: Daytona Beach
Posts: 191
Default Spark knock

I hear a little banging around in my engine I hope it is not a bearing bounching around in there. I just put high octane fuel in it today, and it still was doing it, do these engines spark knock?
Reply With Quote
  #2 (permalink)  
Old 05-15-2008, 01:56 PM
Master Motorized Bicycle Builder
 
Join Date: Mar 2008
Posts: 146
Default Re: Spark knock

no, at a 6.5:1 compression ratio, you could run kerosene and it still wouldn't knock.

What you have is a worn wrist pin bushing giving you notice it needs to be replaced. Do it sooner rather than later or you could really damage your engine.
Reply With Quote
  #3 (permalink)  
Old 05-15-2008, 05:23 PM
Bikeguy Joe's Avatar
Moderator
 
Join Date: Jan 2008
Location: Ashtabula county, Ohio
Posts: 2,168
Default Re: Spark knock

At least take it apart and check it for play. Pop off the head and jug and check the piston for loseness up and down on the rod....I believe Norman can tell you exactly what it feels like or Ilikeabikea, since they worked on Normans bike awhile back and I remeber reading comments on the loose bushing.
__________________
If it ain't broke, and you mess with it long enough, it will be.
Reply With Quote
  #4 (permalink)  
Old 05-16-2008, 12:41 AM
Master Motorized Bicycle Builder
 
Join Date: Mar 2008
Posts: 146
Default Re: Spark knock

Remove the piston and then stick the wrist pin in directly into the bushing. Clearance should not exceed 1 RCH-rch is a military unit of measure and is a very small amount that is barely visible.
Reply With Quote
  #5 (permalink)  
Old 05-16-2008, 09:44 PM
Norman's Avatar
LORD VADER Moderator
 
Join Date: Jan 2008
Location: pampa texas
Posts: 1,021
Default Re: Spark knock

you might be getting piston slap)caused by piston too loose in cylinder) or the piston might be hiting the head (caused by the base or head gasket too thin or the head is not machined properly and tapping the head at the edge of the heads machined sealing ring)
I don't think you will hear preignition knock form these engines. I set the base gasket too thin on an engine and it will make a very strange sound when the piston taps the head and it will tap only when wound out.
burning anything but regular gas is a waste of your hard earned money in these engines.
__________________
norms-iron-works.tripod.com
motor assisted bicycle engine headlights that work off of your white power wire. check it out
Reply With Quote
  #6 (permalink)  
Old 05-17-2008, 01:00 PM
Master Motorized Bicycle Builder
 
Join Date: Mar 2008
Location: Daytona Beach
Posts: 191
Default Re: Spark knock

Think my gaskets will stay intact, when I take the head off or will I need new ones, could I use some of that high temp RTV, also do I need a ring compressor to put it back together?
Reply With Quote
  #7 (permalink)  
Old 05-17-2008, 01:10 PM
Ilikeabikea's Avatar
Moderator
 
Join Date: Jan 2008
Location: Pampa, Texas
Posts: 883
Default Re: Spark knock

On the gaskets you just don't know if they'll stay intact until you take them off. If they tear you can make new ones pretty easy. If don't think I'd use RTV. Aluminum paint works pretty good though to seal gaskets. And you won't need a ring compressor. There are only two rings. One word of caution. There are some little tits (for lack of a better word) that are in the ring groove. Be sure you get the ring gap around the tits. It keeps the rings from turning. If you try to put the cylinder on with the gaps somewhere else you won't like it. It's no big deal, just something to look for.........................
__________________
There are only 10 kinds of people in this world. Those that understand binary and those that don't............

http://bdconner.com
Reply With Quote
  #8 (permalink)  
Old 05-17-2008, 06:01 PM
deacon's Avatar
Master Motorized Bicycle Builder
 
Join Date: Jan 2008
Location: north carolina
Posts: 2,331
Default Re: Spark knock

On the ring thing be very sure to look out for it tits he mentioned above the big thing is your ring will break if you try to but in over that little bump. Ask me I broke two before i found out.

You know what is good about this forum somebody told you about that without being asked because they know that is the most likely problem you will run into. I like that alot about this place. People actually try to look out for each other.
__________________
visit my blog if you dare ... Riding in the hood, The deacons facts and fiction.... http://chinesekitmotorbike.blogspot.com/
Reply With Quote
  #9 (permalink)  
Old 05-17-2008, 08:38 PM
Bikeguy Joe's Avatar
Moderator
 
Join Date: Jan 2008
Location: Ashtabula county, Ohio
Posts: 2,168
Default Re: Spark knock

Heh heh...you guys both said "tits".
__________________
If it ain't broke, and you mess with it long enough, it will be.
Reply With Quote
  #10 (permalink)  
Old 05-17-2008, 08:39 PM
Bikeguy Joe's Avatar
Moderator
 
Join Date: Jan 2008
Location: Ashtabula county, Ohio
Posts: 2,168
Default Re: Spark knock

Those are "anti rotation pins"...I like the other one better.
__________________
If it ain't broke, and you mess with it long enough, it will be.
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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Won't start - no spark (possibly) swodell Bicycle Engine Kits 17 06-06-2008 02:37 PM
Spark plug replacement sisdavid Bicycle Engine Kits 18 05-27-2008 02:42 PM
spark problem dazdog Bicycle Engine Kits 10 05-05-2008 09:27 PM
Spark plug wire and boot. ran49 Motorized Bicycle General Discussion 12 04-01-2008 02:39 PM
Loss of high RPM spark? Pablo Bicycle Engine Kits 93 03-28-2008 11:14 AM


All times are GMT -5. The time now is 02:27 AM.


Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2008, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.1.0
Motorized Bicycle Engine Kit Forum vBulletin Optimizations


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22