Jetting - GT186, 30PHBH, TSR EVO

[Donnie]

So, after finally getting the exhaust to fit I need to get the timing and jetting done.

So, its a 30phbh coming out the normal side on a GT186, no packers, exhaust port lowered slightly, Ram air filter on end of air hose, static indian wassel ignition set at 17 BTDC.

Nearly forgot, this also has a boost port between the casings and back of the reed valve if that makes any difference.

The current set up on the carb is

Main Jet 125
Atomiser AV266
Slide 40
Needle X13 (top clip i.e. weakest)
Pilot / idle jet 50
Choke jet 70
Float 8g

Float valve is a 200.

So, im thinking all this will be fine (was on a mugello 186 and 42mm clubman) for getting the ignition sorted, but obviously Ill need to get out on the road and go from there doing plug chops etc.

But wondered if anyone had any suggestions on anything i may have glaringly missed? Im wondering if it's really worth upping the float valve from a 200 to a 300?

[dickie]

Those are close to what rich Taylor recommends with a franspeed race. Except that he suggests av268.

[Stevepshipley]

My 198 mugello and tsr evo with 30mm delorto is

125 main
X13 top clip (I think)
AV 266
40 slide
55 pilot
Float 300
Cheers steve

[burnside]

That looks a little on the lean side to me. This is the jetting for mine GT186, 30 PHBH, Fran Race, I bought the carb from Rich T and he set it up, haven't had the need to change it;

135 main
X13 needle, 1 clip from top
AV268
40 slide
55 pilot
70 choke
300 float needle

Initially I thought it would be on the rich side but if anything may need to raise the needle one clip

[Donnie]

Looks like im fairly close then I'll start with a 135 main jet then too and work down, plus order the 300 float valve.

Thanks chaps.

[bazza3004]

Same as what your jetting is apart from i had a 128 main

[mainstand]

I'm fitting one of these soon, good to see some info re the set up. Can I ask what gearing & chain you lot are using please?

[Donnie]

Im using an Li150 box and 16 / 46 with a 81 link chain and pull down chain guide.

Had a quick go today but as soon as I was about to go out to set up the carb I could feel a bump, basically had to trim even more off the rear footboard. By the time I'd sorted that it was getting dark. So, if the weather holds ill be out jetting tomorrow.

[burnside]

Mine is as per Donnie's but with a 17 front sprocket...changing to a 16 this weekend though as struggling to pull that gearing a little

[Donnie]

finally got a break in the weather to get a quick hour out on the road!
Started off with the following, float needle valve is still a 200 but a 300 is on its way.

Main Jet 135
Atomiser AV268
Slide 40
Needle X13 (top clip i.e. weakest)
Pilot / idle jet 50
Choke jet 70
Float 8g
Float valve is a 200.

So, idle and slide seem ok right out of the gate but was wary that mid range all i had changed was the atomiser to a AV268 from a AV266 but left the x13 on the weakest setting figuring it should be close, however its pulling like a train, lovely feeling when the expansion kicks in!
Of course that could well mean its running lean but the problem is that its a new plug and while its starting to colour up already, it's too early for good reading on plug chops
So, figured i'll move the needle one notch richer but it made no difference really, therefore ive moved to the bottom (richest setting) and the difference was quite evident ie its quite burbley at town speeds ie 30 ish but once the power kicks in it wants to fly!

Granted i skipped the 2nd to last clip, which i suspect would clean up the burble to some degree round town (started piddling down so headed home) but then it might be lean when on the open road so now im thinking maybe a different needle, ie one that has a shorter taper which would be leaner at the lower end, or swap the atomiser to an AS rather than an AV?

[Toddy]

Just to ressurect this one, im building a lad a GT186 30mm PHBH and Clubman Pipe any updates on the jetting in the thread or still the same ? also gearing wise was looking at LI150 16x 46 @ 4.9 any thoughts or recomendations please

Cheers Toddy

[burnside]

Just to ressurect this one, im building a lad a GT186 30mm PHBH and Clubman Pipe any updates on the jetting in the thread or still the same ? also gearing wise was looking at LI150 16x 46 @ 4.9 any thoughts or recomendations please

Cheers Toddy

I'm running the same gearing on my GT186/PHBH30 with Fran Race, it's about as tall as I'd like to go with that pipe but should be fine with a clubman.

[Toddy]

Just to ressurect this one, im building a lad a GT186 30mm PHBH and Clubman Pipe any updates on the jetting in the thread or still the same ? also gearing wise was looking at LI150 16x 46 @ 4.9 any thoughts or recomendations please

Cheers Toddy

I'm running the same gearing on my GT186/PHBH30 with Fran Race, it's about as tall as I'd like to go with that pipe but should be fine with a clubman.

Thanks, Same jetting as earlier post buddy ?

[dickie]

Which clubman? Mine needed altering when I changed from ancillotti to bgm.

[Toddy]

Which clubman? Mine needed altering when I changed from ancillotti to bgm.

Ancillotti

[Storkfoot]

My GT186 has been on the road for 7 years now (just checked and I was quite shocked it was that long!). Same carb and with an MB/BGM Clubman, the first version.

Anyway, agree that LI150 box 16/46 is the way to go.

Needle valve 300, choke 70, pilot 55, Slide 40, main 122. The atomiser and needle was AV264/x13 clip second from top. But, since I fitted a breath sweet filter a couple of years ago it has been Av266 x7 2nd from top clip.

Hope that helps, Paul.

[Toddy]

My GT186 has been on the road for 7 years now (just checked and I was quite shocked it was that long!). Same carb and with an MB/BGM Clubman, the first version.

Anyway, agree that LI150 box 16/46 is the way to go.

Needle valve 300, choke 70, pilot 55, Slide 40, main 122. The atomiser and needle was AV264/x13 clip second from top. But, since I fitted a breath sweet filter a couple of years ago it has been Av266 x7 2nd from top clip.

Hope that helps, Paul.

Cheers buddy great help

[burnside]

Just to ressurect this one, im building a lad a GT186 30mm PHBH and Clubman Pipe any updates on the jetting in the thread or still the same ? also gearing wise was looking at LI150 16x 46 @ 4.9 any thoughts or recomendations please

Cheers Toddy

I'm running the same gearing on my GT186/PHBH30 with Fran Race, it's about as tall as I'd like to go with that pipe but should be fine with a clubman.

Thanks, Same jetting as earlier post buddy ?

Yes but it is slightly rich mid-range, I will get round to sorting that at some point

[Donnie]

Just to ressurect this one, im building a lad a GT186 30mm PHBH and Clubman Pipe any updates on the jetting in the thread or still the same ? also gearing wise was looking at LI150 16x 46 @ 4.9 any thoughts or recomendations please

Cheers Toddy

I got rid of the TSR as between it being too low and the fragile exhaust port of the GT I ended up breaking the exhaust port flange twice in two years I loved the combo but once bitten twice shy. Now back to my muggy and CST3.

[Simon_T]

Just to ressurect this one, im building a lad a GT186 30mm PHBH and Clubman Pipe any updates on the jetting in the thread or still the same ? also gearing wise was looking at LI150 16x 46 @ 4.9 any thoughts or recomendations please

Cheers Toddy

I'm running the same gearing on my GT186/PHBH30 with Fran Race, it's about as tall as I'd like to go with that pipe but should be fine with a clubman.

Thanks, Same jetting as earlier post buddy ?

what crank and rod mr T

I have a similar setup but will be utilising a RM clubman.

cheers