Project Bens GSX250 Cafe Project

Hi Guys,

Due for an update post engine rebuild. Engine re-fitted and the bike runs well, compressing 120psi per cylinder and idling beautifully. It has a strong exhaust now and a nicer note. There are 0 oil leaks, even through the exhaust and side covers. Positive crankcase pressure fixed!

So the cylinders need to be run in, under load and not sitting at idle too long. These mikuni carbs are fine at idle, but are flooding the engine when I open the throttle. The importer says the Keihin CR's are only about 1-2 weeks away. So avoiding the risk of glazing the cylinders I am going to have to be patient. This means that I'll affix the seat, and work out some electrical stuff (one weaker coil, brake light switch in the master cylinder is backwards, I have to finally clean up the electrics and wrap the loom)

 

Hi Angel, welcome mate!

I had a friend reset the float heights with his carb balancing set and a vernier calliper to test the factory clearances. That certainly stopped my bowls flooding! He also soda blasted the carb bodies for me and we checked all the gaskets. It's certainly helped get the bike idling but when it comes to the vacuum behind the constant velocity carbs there's no helping that I don't have an airbox so i'm replacing them for mechanical carbs.

 

Well, this happened today.

After months of waiting, anticipation and questions they arrived. Expertly packed, jetted and cast these are so light! They fit the bike nearly perfectly, I just need some linger spigots to get the throttle cable tree away from the engine a little more for full throttle.

I've already got the bike idling and revving past what it was on the old CV carburettors. Its in a reasonably rideable state engine wise. I just need to modify some cables and add the roadworthy rubbish.

Video's to come once its tuned

 

Hi Clancy1,

I got them from Modern Motorcycle Company http://www.shop.modernmotorcyclecom...rs/products/clip-on-handlebars-classic-chrome

They are 33" I think, I cant remember that was 2 years ago almost haha. Best to measure your forks or look up in the manual anyway. They clip my tank a little so I have to adjust the steering but its because of the seat length and small tank shim forward that I did.

Hope that helps

 

Guages were the chrome ones, white background with the headlight/neutral/oil/indicator lights wired in. Took a few resistors to get the LED's working but after some soldering they were perfect! I think the speedo was 1/4. Hope that helps

 

Okay, so a massive update. Rant begin:

After taking the bike to the dyno guy, he wanted a higher level of finish done on the bike before he put it through its paces. After charging me an exorbitant amount for changing my fork seals I took it out of there to a local bike mechanic called "Antique Motorcycles" in Moorabbin near me.

Not only is this the first time I've been greeted with a smile but they were attentive, thorough and QUICK! They are a club/mechanic and roadworthy inspector all in one, with some AMAZING bikes in the collection. (And a bar! lol)

The next day they called me up and told me that the roadworthy would fail, because the welding I had done for my rear-sets was "life threateningly bad". They could actually break them off with their hands.... I was shocked and angry. They needed to cut them off and remake them with 6mm steel instead of 3mm, and remake the allthread controls for the break and gear lever out of steel with additional tension springs and nuts.

Unfortunately the F**KING IDIOT that welded them in the first place is not really that receptive to "customer complaints". So that money is gone, but I called the Kustom Kommune and told them to recommend him to no-one anymore. They apologised and let me know that he's not been seen for about a year anyway. Life threateningly bad... I should have followed my instinct in the first place, but it was my first bike and I was excited someone could do it in the shop.

They also did my steering stop to stop my tank slap, changed my head stem bearings to correct ones (loose), mounted my seat and battery with custom brackets and tuned my carbies to a rideable state!

In the end the bike is fully registered, operational and I've taken it for its first ride.

Other than the charge circuit not being dodgy still (fixing that this week) and some clutch slip (plates on the way) I can now take it back to the dyno and get these CR specials tuned magnificently. You should HEAR the thing. I'll find a mate with a helmet cam and film something for you soon, its incredible. The mechanics couldnt belive "the racket coming from that little bike"

So finally, the carbs run well at idle, have a flat spot at about 7000 rpm that I cant get past in second third or fourth just yet (so im speed limited to 70kmh until the tune) but in first when you get past 7000rpm the power is explosive! Actually seriously fast.... I'm surprised what these mechanical carbs deliver at high RPM, they are fiddly because you have to keep the throttle open to match the rpm, you can't just wind the throttle full open and let it climb because that starts to flood the engine. But when you match it and twist the grip holy **** it moves.

Anyway here's a few photos, looking forward to the tune and the charge circuit being done then i'm out on some rides!

2 years almost to the day. Thanks for all the tips and advice, I appreciate everyones input and those that went above and beyond to send me parts for testing (Grey)