Gt186 / cyclone 5 /FDR?

[swissdean]

Morning, trekking it from Switzerland to Woolacombe and struggling to pull top gear on my cyclone 5(v2). Curios what others are running . My set up is gt186 ( out of the box), 110/60 crank, 30 mm phbh, 18 degs static, casa perf filter, 4.71 fdr with 46/19 cogs and bgm v4 sport ( curly one)

Pulls lovely to 7400 rpm in every gear, flip from 4th to 5th and it drops from 7000 plus to anywhere between 5800-6200 rpm, will sit all day there which is between 60-64mph I guess ( speedo is in giga counter above 40! ) but was hoping it would pull more

What cogs are others running and what are you cruising at in 5th ( either rpm or speed) please

Thanks

[nsaints]

Regardless what the manual says I found my GT186 happiest with a FDR of 5.0
BGM exhaust, 25mm, modified airbox

[Warkton Tornado No.1]

From one brief try of a friend's GT186 my impression is of a torquey engine. However, as you say:

"My set up is gt186 ( out of the box), 110/60 crank"

then perhaps port timings remaining as for a 58 mm stroke is the issue here

[Storkfoot]

I have run many thousands of miles on a GT186 with an MB/bgm Clubman, although more latterly with a Ron Moss Avanti. My final drive has been 4.9 and it is fine. I did once try it with 4.6 but it wouldn’t pull it. That’s always been on a four speed gearbox.

[jonw]

From one brief try of a friend's GT186 my impression is of a torquey engine. However, as you say:

"My set up is gt186 ( out of the box), 110/60 crank"

then perhaps port timings remaining as for a 58 mm stroke is the issue here

Modified timings are on the link below.
viewtopic.php?f=7&t=8343&p=72224#p72224

I had a GT186 with GT 60-110 crank, 3mm packer, PM Pipe, 30mm PHBH, 16-47 Pacemaker box which would rev to just over 8K.
Dynod at just over 19hp before I put the 60-110 crank in and it felt stronger after.
It also was happiest at 60 on A roads.

[swissdean]

I have run many thousands of miles on a GT186 with an MB/bgm Clubman, although more latterly with a Ron Moss Avanti. My final drive has been 4.9 and it is fine. I did once try it with 4.6 but it wouldn’t pull it. That’s always been on a four speed gearbox.

Funny, that’s exactly what I’m thinking, drop first cog to an 18.. will give it a go when I get back

[swissdean]

I have run many thousands of miles on a GT186 with an MB/bgm Clubman, although more latterly with a Ron Moss Avanti. My final drive has been 4.9 and it is fine. I did once try it with 4.6 but it wouldn’t pull it. That’s always been on a four speed gearbox.

Yep, that’s two of you saying the same.. mind made up,

[Toddy]

I have run many thousands of miles on a GT186 with an MB/bgm Clubman, although more latterly with a Ron Moss Avanti. My final drive has been 4.9 and it is fine. I did once try it with 4.6 but it wouldn’t pull it. That’s always been on a four speed gearbox.

Same as Paul running mine on 4.9 li150 46x19 lovely ride

[dickie]

I have run many thousands of miles on a GT186 with an MB/bgm Clubman, although more latterly with a Ron Moss Avanti. My final drive has been 4.9 and it is fine. I did once try it with 4.6 but it wouldn’t pull it. That’s always been on a four speed gearbox.

Yep, that’s two of you saying the same.. mind made up,

I ran mine initially at 4.7 with ancillotti clubman and 25phbl. I then changed to bgm clubman and phbh30 and it still wasn't happy.

Once I changed to 4.9ish it was MUCH nicer to ride.

Funny what a difference 5% can make, but it does.

That's 3 of us now.