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Re: help starting it up
Posted: Sun Feb 28, 2010 9:54 pm
by leehuggy72
The reason I say all this is that you could spend months with the OKO and spend a lot on jets and needles, and then still find it's not quite right. If I still had my Mugello 186, and knowing what I do now, I'd go TM24.
SO before i go deep into this
you say mikuni.... how come a tm24 and not a larger carb like a keihin 28/30 as before..
do they give same power,economy,efficiency than a larger carb.
i still might have an oppurtunity to buy a mikuni tm28 is this the right size or erring on the larger side for what i need....
I just want the best carb i can afford and learn off people who have had these and problems associated with them, and if that means stopping using a copied keihin and spending more money, but eventually should benefit in the long run
Re: help starting it up
Posted: Sun Feb 28, 2010 10:13 pm
by coaster
I'd say the size of carb you need depends a lot on what you want to use the scoot for. A 28/30 isn't necesarily too big especially if you are running a revvy pipe but if touring or town riding is your normal style then I'd definately go for a smaller carb. I've often thought the 26mm? PWK would havre been a better bet, I'd get more MPG and it would probably pick up better.
Re: help starting it up
Posted: Mon Mar 01, 2010 2:51 pm
by storkfoot
Lee, there's no definite right or wrong answer but if you've got the new balls out Mugello version and an expansion like a PM25 or a JL3, and you want to ride flat out everywhere, then a 28mm carb is OK. But, a TM24 would still be able to flow the mix, it would use less petrol, and would be responsive. One down side if you go down the TM24 route would be that you'd either need a new manifold or, as I did, buy a stepped rubber one.
Also, there's plenty of lads who have experience of the TM24 whereas the Mikuni 28mm is not as widely used. That said there's even more lads with experiences of Dell'orto PHBH carbs. It's your shout
Re: help starting it up
Posted: Mon Mar 01, 2010 3:38 pm
by lee b
my muggy 225 has the phbh 28mm delly on it and goes really well,i can vouch for that,no probs as yet.
Re: help starting it up
Posted: Mon Mar 01, 2010 3:44 pm
by TheSeeker
coaster wrote:Lee, if it's any help, my Mk1 Mugello 186 with PWK 28/30, BGM 120 (standard indian flywheel) and Sito Ancilotti has the following jetting:
Pilot - 34
Main - 138 (Yes I know that's huge but I holed 2 pistons on smaller mains
)
Needle GJH needle in top clip
Timing is set to 17 degrees
Squish was about 1.3 when I originally built it.
Starting from cold can be a bugger if I havn't used it for a week or so, maybe I could go up in the pilot but it runs just fine otherwise, nice and clean through the rev range and doesn't 4 stroke too much on feathered throttle.
When starting I have found that it likes the throttle to be closed (warm or cold start), wait till it fires and be ready to open the throttle a very little way untill you can feel that it's caught, then blip it until its warmed up.
Good luck
Hello Coaster
This is very close to the setup in my cutdown. Starting from cold is also difficult but after 3 "starts then dies" it picks up and goes. Can I ask which pilot jet was fitted as standard? I have a BGM PWK carb from Scooter Center and I can't find this documented anywhere. I'm planning to buy one pilot up and one down but I have no idea what I currently have fitted.
Ben
Re: help starting it up
Posted: Mon Mar 01, 2010 8:34 pm
by coaster
Mine was a scootrs okond came with a 32 cited and a 34,36,38 sullied along with 105, 107,110115 mains
Re: help starting it up
Posted: Tue Mar 02, 2010 12:14 am
by leehuggy72
evening,
just gonna try and get my head round these carbs and play a little.. don't want to give up yet..
few questions if you guys can help..
1. downdraught manifolds any good ? where can i get one if so ?
2. i've changed float to 22mm, what should the float needle hole look like when looking down it..
3. the float bowl i have is the clear plastic type, were do i need to grind off this plastic stop you all mention about.?
4. what do the bgm needle sizes translate too, 21,24,28,30 ?
many thanks for your help so far, regards lee
Re: help starting it up
Posted: Tue Mar 02, 2010 8:42 am
by minotaur
i4ve got a 30mm oko pwk, changed manifiold from scootrs type to mbd and it is now easier to start
Re: help starting it up
Posted: Tue Mar 02, 2010 11:27 pm
by storkfoot
leehuggy72 wrote:
1. downdraught manifolds any good ? where can i get one if so ?
2. i've changed float to 22mm, what should the float needle hole look like when looking down it..
3. the float bowl i have is the clear plastic type, were do i need to grind off this plastic stop you all mention about.?
4. what do the bgm needle sizes translate too, 21,24,28,30 ?
Lee,
1. CamLam or Mike Phoenix will probably have the Mugello downdraughts, or at least used to. They give better clearance from the engine mount. Remember though, if you go smaller on the carb in future, it'll be too big.
2. Hmmh, a hole
If you take the carb off and gently tip it back on it's side, the needle should seal the hole.
3. Don't know. Never had to do this on a bgm.
4. I'll lay good money no-one will know the answer to this. Not sure that Scooter Center do either. You could get digital verniers and compare the diameter, taper etc with the ScootRS tech pages if you
really wanted to know. Personally, forget it and buy a GJH and JJH from Allens to start with. At least then if you read the chart on the ScootRS tech pages, you can see where they go weaker/ richer etc
Good luck
Re: help starting it up
Posted: Wed Mar 03, 2010 1:51 pm
by corrado