I found my heavily rich problem, I think

[Rusty McNeil]

Went through the carbs again last night to have a look and change some jetting and think I found a problem causing my heavy rich issue at idle and up.

Underneath the jet block there is anl o-ring that goes around the brass tube that the needle slides in to. There is a sligh bevel on the back of the jet block to accomadate this o-ring when the jet block is tightened down.

The o-rings were dried out and frail and I had replaced them at the start of this engine project with some of the correct diameter but that were thicker than the old ones.

I didn't realize they were TOO thick, I found that even though the jet block screws were very tight, they were just compressing the heck out of that o-ring but not pulling the jet block down tight and getting a good seal on the jet block, the jet block gasket and the carb body......I could see a visible gap where the jet block should have been tight against the gasket. I missed this last time...

I'm thinking this had to have been contibuting to some kind of problem.....

I put the carbs back together and have them ready to mount and try 'em out this evening or Friday...hope I found it...unk:

 

[tugla]

good feeling when you find a reason they are not working right rather then a anomaly i , sweet, i assume you rechecked the float level while you were in there right?

 

[mr.maxx]

good job Rusty!!! easy to overlook lil things like that....

 

[Dr.n2o]

Nice job....let us know how it turns out

 

[vmaxinID]

Best wishes unk:

 

[Rusty McNeil]

Thanks guys, I hope it turns out to be something simple like this...I was going nuts trying to figure out how the same jetting I had before except for the mains could be rich at idle and cruise when the engine displacements gone up 28% WTF:ummm:

I'll keep you updated..

And I did recheck all the float levels too... right on the money at 1.120"

Actually that's why I noticed it cause I took it out in the bright sunlight to get a good look at the dial caliper "touch" on the float and thats when I saw that gap where the gasket is..

Thanks,

Rusty

 

[maleko89]

Cool, Rusty. That would definitely do it....same if those rubber jet block caps wear out.

 

[one2dmax]

Correct. All must fit nice and tight!

 

[Rusty McNeil]

Ok, fixing those o-rings and getting the jet blocks seated properly did the trick.

I installed Mikuni 190's while I was in there, and removed the 177.5 PAJ2's and installed 182.5's

Stg 1 needles on leanest clip and stock springs with two coils cut just like my old setup......I do have some stage 7 & springs and needles on hand...Plus a butt load of jets now...

It's now close enough on top to start tuning, Looks like the mains are about right; 12-13:1 at WOT up around 8500-9000rpm

At a steady 3/8-1/2 throttle 6500-7500 rpm in 3rd or 4th, 65-85mph it is also running around 15:1, I think the motor is working hard enough at this point the a/f needs to be richer than that so I think I need to richen up the needles a clip or two to adress that????:ummm:

At part throttle cruise it's around 15.5:1, Probably OK for cruise but may richen that up a tad cause I'd rather sort this out from a rich condition down rather than running lean, so I think thats going to be the PAJ2 back down to the 177.5's????:ummm:

Once I get the a/f satisfied where I don't think I'm going to burn it up then I'll ignore the a/f guage and start tuning it to feel using the factory pro method.

Any carb gurus want to say if i'm on the right track here??:confused2::confused2:

Here's the new problem tho.

I was running it thru it's paces in each gear starting from about 2500-3000 rpm up to 8500-9000 and then letting it back down to slow speed and then doing it again from the next gear up to see what the a/f was doing.

One of those times when I closed the throttle and it was winding down in gear I looked in the rear view and there's a huge cloud of blue smoke rolling out of the exhaust pipes. I'm like oh fuck, destroyed the rings or burnt a hole in a piston or something.:bang head:

It went away and I drove normally on the way back to the house and it was fine.

I get off and notice oil all over the place around the carbs, running down from there. I start looking and digging and figure out that the shitty stg 7 crankcase ventilation system dumped an ass load of oil down the front two carbs.
Pull the air filter and the inside of the two front pods are soaked in oil and the carbs are oily as hell inside as well.

The little aluminum restrictor orifice that goes in the smaller down tube is in place, everything is just like the manual says.
Is there a better way to do this job?

I'd go back to the air box setup but would have to find a new home for my Wideband a/f brain and the air horn motor, plus I don't know if this bigger motor can be fed thru the stock airbox...maybe with no wye installed??

How do the flatslide guys deal with this, just blow it to atmosphere with a catch can and not use any positive ventilation??

Any one have an opinion on that?

 

[ouchez]

I have read on the Hole Shot site that Walker says to always leave on the stock air box, is this the reason why I wonder?

O

 

[one2dmax]

We put a catch can onto the reaper bike. Worked well!

I may have a picture somewhere (and it has flats on it too).

Sean

 

[sdt354]

I have read on the Hole Shot site that Walker says to always leave on the stock air box, is this the reason why I wonder?

I think it depends on what you're after tuning wise. With a stock motor running on the street I like the benifits of the air box. Just my h.o.
Steve-o

 

[Rusty McNeil]

We put a catch can onto the reaper bike. Worked well!

I may have a picture somewhere (and it has flats on it too).

Sean

What's the philosophy? A place to vent and a big enough catch can to hold it all till it has a chance to run back in the motor.
Do y'all run it from the oil fill hole, the stock PCV hose, or both?

 

[one2dmax]

Shoot me an email and i'll try to get a picture.

 

[Rusty McNeil]

Shoot me an email and i'll try to get a picture.

K. Thanks.

If I ever get this this tuned it's gonna be a beast. Even tuned poorly it's stupid fast!

 

[Rusty McNeil]

Bump

Mark or anyone else;

What do you think about the jetting/tuning questions??

 

[gamorg02]

rusty i'm not an expert but i'd agree that 15:1 seems too lean for the 3/8-1/2 throttle but 15:1 for cruise i don't believe is bad at all. i'd address the 3/8-1/2 and it might also help the cruising.

 

[tugla]

whats it doing at wot?

 

[Rusty McNeil]

whats it doing at wot?

Other than spinning tire? : )

It's so lean coming off the needle, around 15:1, I am scared to run it to hard into the main. I thought it was around 12-13:1 but haven't seen that again. I used the choke to get it off the needles and then when on the main started pulling the choke and it climbed pretty high. Not going to do that again till I get some bigger mains in it and am able to tune it from the top. Down the way it's supposed to be done.


I've got some more jets ordered. It's got a mikuni 190 main now, ordered 210, 220, 230's

 

[one2dmax]

Recheck the float levels. Shouldn't need that much main I would not think.