Gearing

[bill]

what ranges of gearing are people using and what max rpm are you using on a 350?

thanks

[steve-e]

All 6 is good And start in 1st

[bill]

hey thought it was my job to put silly replies to perfectly sensible questions

but will keep your information stored just in case i have a momentary lapse of concentration

ta

[little chud]

Hi Bill,

Not sure what we've been ruinning on the front but 36 on the back. I'll check when I next go to the workshop. I think most of the teams run the same gearing for all tracks, although not the same as each other. Not sure I agree with the first part of this but we're not clever enough yet to do our own thing. Might try some changes this year.

As for revs. Again a few of us are running john roberts ignitions which have a change light at 10500 i think and limiter at 11000. I guess the power is dropping off quickly after 10k so these seem to work OK. I like it becuase I'm pretty heavy on the revs so its nice to know I'm not going to kill the engine every time out.

Its worth talking to Alan Steele about it. He's a font of knowledge when it comes to 350's. Trouble is he's ill at the moment so best to give him 2-3 weeks.

hope this helps.

jc.

[martyf350]

we used to run 15-36 as an allround setup but if you go somewhere with a long straight i think we ran 37 0r 38 on the back.im sure people used to say goin up 1 tooth on the front was equal to 2 on the back.we did have a chart that showed what gears give what ratios dave saunders may have this if ray passed it on when he bought the bike

marty

[steve-e]

you'd go down on the back for long straights - one up on the front is nearly two down on the back but not quite.

[David Saunders]

Hi Bill I run 15 X 37 used to be 16 X 36 but the 15 X 37 seems to get you off the line a bit better and puts a little less pressure on the clutch. As for revs I've got a red line of 11500 which is about peak power although the bike will revto at least 13000 but probably not for long. My crank has now done around 600 race miles and is looking good for another season ( I hope I'm not speaking to soon ) so keeping to 11500 seems to work. I change pistons and rings every 300 miles and use Valvoline oil. I do have a chart for the gearing so if anyone wants a copy I could post it to you. I don't think I know my way round this to be able to attach and post it here.
Dave

[bill]

thanks everyone

i have gearing chart

do people still use mikuni vacuum petrol pumps?

if so where to you pick up on the engine?

ta

[little chud]

Hi Bill,

we used a vacum pump intill the festival last year and then switched to electric. As it turned out there wasn't anything wrong with the pump, we had a very hard to find blockage in the tank outlet. We run a battery so fitting the electic was easy enough and worked a treat at cadwell and the plumb pudding.

Our vacum was taken of the back of the left hand crancase. This was done when we got the bike but it looks like a short bit of car copper brake line, glued in place with some kind of epoxy glue. The people in the know say to make sure that the vacum pipe is as short as possible and is strong walled. Gives a good strong pulse then at the pump.

I'm pretty sure Chris Jolly runs two vacum pumps. If one fails the other still works.

I'm not sure what we did with our pump but it might be kicking about for spares if you want it.

Dave, thanks for the tip re 15/37. I might give that a go. see if I can make a clutch last more than a race.

cheers

John

[bill]

Cheers John

[martyf350]

when we switched from electric to vacuum me drilled a hole in the right hand cylinder,tapped it then used pneumatic airline fittings to fix the pipe in place.we used a small diameter plastic pipe.i have seen them set up before comin out from the top of the crankcases behind the cylinders

marty

[little chud]

Hi Marty,

when I fitted one to our scooter sidecar, I tapped into the carb rubber between the carb and reedblock. this worked fine. I've also seen them like you say in the cylinder, not sure if they tap into the inlet or transfer port? but defo not th ewater jacket

john.

[martyf350]

good point i didnt mention that i think we tapped into the trasfer port to get the pulse

how are things goin for the start of the season?

marty

[little chud]

Not great. Poor old Alans been in hospital having his apendix removed so our engines have got as far as been stripped. Doug spoke to him yesterday and he sounds a load better and keen to get on with them. I guess we will have them beck by the end of feb.

Hopefully we will be getting the fairing fitted in the next week or so. Then painted. So again shud done in time.

then the normal stuff to do, clean, lube etc etc etc etc etc etc

I'd like to get out for the 9th march at elvington to get some track time but if not we'll get a day a teeside or mallory before the first round.

How about you? you deffo out.

jc.

[martyf350]

yeah hopefuuly goin to ring aden just to make sure things are still as we left it when we spoke before christmas!im chomping at the bit i just wana get out there asap

marty