Another vibration thread.
- Thread starter Josh Cox
- Start date
- Status
- Joined
- Oct 19, 2005
- Messages
- 18,978
Either not doing comp check correct or definitely got leakages. Here ball park to think with
I found an article in an old Classic Bike magazine on
testing compression which may be of some general assistance.
Here's the gist of it:~
In the absence of manufacturers quoted figures expect the
following pressure from different Compression Ratios:
6:1 88-118;
7:1 103-147;
8:1 125-162;
9:1 140-176;
10:1 162-191;
11:0 176-206.
I found an article in an old Classic Bike magazine on
testing compression which may be of some general assistance.
Here's the gist of it:~
In the absence of manufacturers quoted figures expect the
following pressure from different Compression Ratios:
6:1 88-118;
7:1 103-147;
8:1 125-162;
9:1 140-176;
10:1 162-191;
11:0 176-206.
- Joined
- Jul 25, 2010
- Messages
- 5,947
aceaceca said:
Mine'd go through a ' chinter ' or hard low amplitude high frequency vibe around 1800 / 1900 rpm . on certain thrttle settings
otherwise what I thought was vibration was road shoch transfered through the handlebars on chip seal roads .Fork stiction .
The head'd move a bit , as seems typical of British ( 360 Deg. Twins ) perhaps. Putting a boot heal on the primary , timing cover etc whilst driveing , it wouldnt slip of from , nor could I detect , vibration . Though we didnt try it over 4.000 rpm .
to busy hanging on .
I adjusted mine today, vibration is gone, thank f*&k.
Blacklav,
Loosen the three bolts that screw into the head, sit on the bike with the stands up, bounce up and down a few times, tighten the bolts down without moving the plate, so there is not pretension.
Blacklav,
Loosen the three bolts that screw into the head, sit on the bike with the stands up, bounce up and down a few times, tighten the bolts down without moving the plate, so there is not pretension.
Thanks for compression ratio`s Hobut.
Josh, i dont believe it. as easy as that. I will do it on saturday and will let you know how i get on.
I had the engine running when i did the comp test, got half way through and the unused spark plug fell off the head and everything stopped. No sparks on both plugs. Phoned an expert up who said I had blown the ignition box in the boyer. So i took it off ready to send to boyer. On phoning them the guy said he had not come across it before and it was more likely to be a faulty coil. So i replaced the unit and did the checks he recommended and strangely everything works ok. I hate not knowing why,could have been a bad connection .
So I will do another comp test without fear of blowing me boyer.
Regards
chris r
Josh, i dont believe it. as easy as that. I will do it on saturday and will let you know how i get on.
I had the engine running when i did the comp test, got half way through and the unused spark plug fell off the head and everything stopped. No sparks on both plugs. Phoned an expert up who said I had blown the ignition box in the boyer. So i took it off ready to send to boyer. On phoning them the guy said he had not come across it before and it was more likely to be a faulty coil. So i replaced the unit and did the checks he recommended and strangely everything works ok. I hate not knowing why,could have been a bad connection .
So I will do another comp test without fear of blowing me boyer.
Regards
chris r
Brooking 850
VIP MEMBER
- Joined
- Oct 3, 2011
- Messages
- 1,618
Pazon electronic ignitions(Andrew used to work for Boyer before he moved to New Zealand and started Pazon) recommends having an old plug earthed to the engine(if it is out of the hole for testing) and keep it plugged into the plug cap while running the engine for carb tuning or any testing. It discharges the system, while not being needed.
Regards Mike
Regards Mike
Hello all, just an update on the vibes issue.
First though my comp tester is useless. I tried it with another ( more expensive one) and got 135 to 140 psi on both cylinders. Woopee.
Now the vibes, I did what you suggested Josh and it made them slightly worse. I tried packing them so the rubbers were tighter, i put spacers in the frame to loosen them, but nothing worked.
so now I`m wondering if the norvil or some other head steady may cure it.
Regards
Chris r
First though my comp tester is useless. I tried it with another ( more expensive one) and got 135 to 140 psi on both cylinders. Woopee.
Now the vibes, I did what you suggested Josh and it made them slightly worse. I tried packing them so the rubbers were tighter, i put spacers in the frame to loosen them, but nothing worked.
so now I`m wondering if the norvil or some other head steady may cure it.
Regards
Chris r
- Joined
- Jan 12, 2011
- Messages
- 1,723
The cheapest, and quite good, rod type head stead is the Dave Taylor.
Handling will be improved because although the head is allowed to rotated fore and aft and up and down, it cannot move side to side, and that is the improvement.
Vibration, about the same with the Dave Taylor, but a quite good upgrade overall for about $200, and you do want the additional spring "option", like the Mark3's come with.
Handling will be improved because although the head is allowed to rotated fore and aft and up and down, it cannot move side to side, and that is the improvement.
Vibration, about the same with the Dave Taylor, but a quite good upgrade overall for about $200, and you do want the additional spring "option", like the Mark3's come with.
- Joined
- Oct 19, 2005
- Messages
- 18,978
I've taken off on analog Boyer after trading plugs with Wes whose low battery/points wouldn't fire em, forgetting one plug wire off till low power to accelerated noticed, no problemo a number of times, so suspect indeed the coil fixed it OR you bumped wires just right and it will show up again.
- Status
