Jemco jollies

[tz375]

I have to remind myself of that all the time. Having raced vintage road race for years, I know how easy it is to get sucked in to that vortex that is racing and trying to get the best out of equipment.

The bike was built sepcifically to be a torquey street tracker type that comes out of corners ahrd but not too much top end. Not the recipe for a good drag bike. Taking it to the strip is just for fun with this bike. It's too seasy to start down the low bars different shocks, programmable ignition etc etc road and that's not the way to go on this one. I do have another that's moere shal we say Supertock eligible that might be the way to go if i like the strip.

I't geared 15-47 at the moment to work with teh 3 into 1 pipe that it usually wears on the street. I thought I had a 50tooth rear somewhere and if I find it i may just throw it on to see what it does.

[RING_DING]

I just have to throw in my 2 cents for the Jemcos. Best thing since sliced bread! I now have two bikes in one.....below 5000 rpm, well behaved and easy to ride......from 5000 rpm the beast is unleashed. I'm having a hard time keeping that front wheel on the deck. My face hurts from grinning ear to ear

[tz375]

Ring_ding,
That looks nice.

Suzukidave,
I ground a few ounces off the shifter and cut off the foot part. Then I took a length of 1/2" steel tube from the hardware store and partially crushed it to make it more oval and welded that on and then welded a blob on the end.



This is how it looks now


Of course it's raining again so I can't take it out to see how well it works.

[Suzukidave]

Good deal you have it sorted and its a setup like that i need to add to the Yellow bikes shift lever .. also the air shifter you have added looks way cool .. very clean looking setup with the polished mount

[tz375]

But unfortunately it doesn't have quite enough throw, so I have to modify the shift lever slightly. The mounting hole needs to be moved 10mm closer to the pivot and 5mm lower to work.

Always one more thing to do.

[D&D CHASSIS]

Richard, you want to have at least an 1/8in. of extra stroke on the air cylinder AFTER the shift lever is fully engaged.....

[GT750Battleship]

Geez mate, you could have run the clutch cable under the tank .


Very nice, BTW.

You beat me to it !!
Regards,
GT750Battleship.

[tz375]

Richard, you want to have at least an 1/8in. of extra stroke on the air cylinder AFTER the shift lever is fully engaged.....

Hmm. I hadn't realized or measured just how far a GT750 shift lever moves, but it's a huge amount. The Ram has around 50mm of travel and the lever moves that much or maybe more at the peg. I welded up the first hole and moved it back and down and I think I'll have to move it again.

On a short run yesterday, it shifted up and down manually OK, but I suspect I'll need a little more travel to avoid damaging the cylinder.

Time to get the gas axe out again..... If that doesn't work I may have to make a new bracket to move the cylinder back an inch or so or design a set of semi rearsets with a linkage that reduces travel at the peg to something more manageable..

[D&D CHASSIS]

Well? How was Indy?

[tz375]

Huge learning curve. Too many operator errors to list. Lots of fun. Adrenaline overdose. Best ET 13.15, highest MPH 107. Need to learn how to launch harder. Good bunch of people. Rocket fuel cleaned up jetting but it's still all over the map. Sunburned. 103 degrees in the shade of an EZ up canopy. Button shifting takes some getting used to. One the throttle is 100% wide open it stay that way for the whole run.

I rarely use clutch on upshifts anyway, but leaving the throttle pinned took a while to get used to.

Now I need to drain that fuel out and flush it with regular street gas and sit down and check plugs and head and pipes etc and go through the data to see what happened. Data logger On-Off button is too hard to operate with gloves, so I need to look at a different/remote activation.

4 ounce CO2 bottles don't last long. Pics should be available in a week or so. If there's a good one, I'll post it up.

[D&D CHASSIS]

Can you make it to Martin MI this September?

[Old School]

I wished now that I had made it down, sounds like you guys had fun. I even had buddies make it down saturday that tried to get me to ride down with them.

[tz375]

Can you make it to Martin MI this September?

At this stage that's a must. I did a quick post race inspection yesterday and replaced plugs with BR8EIXs, flushed out the race gas and repacked the noisy Jemco mufflers with fresh packing. When I looked in the cylinders, there appears to be some scoring but I don't want to bore it out yet. That can wait until I have it apart over the winter for a HP transfusion.

If I go up on bore size I have to move up to the next engine capacity class. GT on stock bore fits in the 490 - 740 class (FF) alongside the much lighter H1 Kawasaki. H2 and any overbored GT go into EE (740-779cc). I'll hit that class next year with fresh bores.

I was surprised how little packing was in the Jemco pipes. It was all pushed up so that only the rear half of the perforated tube was covered. I'm hoping that the noise level drops.

[Suzukidave]

And here i was hoping you would put in a solid tube and make stingers out of them

[tz375]

Funny you should say that Dave. I was thinking the same thing last night but I didn't have any Cro Mo tube the right size to try. For the street it has to be much less noisy. My thought was to get three lengths of thin wall tub and slip them inside the perforated tube for track use.

I doubt that it would make much more/any more power but might sound meaner.