David, let us know how your Mikuni works out, and what you had to do to get it in there.
The FCR looks to be too dificult to fit for my liking.
The BB carb seems too small for the 351 so i'd like to see the results of the 36mm.
Thanks,

 

Great advice Mikko. Thanks. Your guide is definitely the way I plan to approach it.

I started with #52-#152 based on the few posts up on this forum and ThumperTalk for the FCR35. There isn't really much info out there for the FCR35 unfortunately, and even fewer posts that state what altitude their jetting is for.

Just today I ordered an #52 and #58 pilot jet, and a #150 and #155 main jet so this weekend I have jets 1 step either way to play with in my testing. I am hoping that will be enough to help get me to the right point. Who knows though

 

TM36-68 off Ebone
$269 + 8 shipping.

Bill's 34 mm $392 shipping included.

It will go on this week.

David

 

FlyingFinn said most of it.


First thing, get the bike to run stationary as slow as you can and keep it running. Even if its 2500 RPM. Then add fuel by covering part of the carb or you could use an un lit propane torch. If the bike smooths out, its too lean

You could also use a can of spray carb cleaner dirrectly in the carb. I would also spray it around your pipe that hooks the carb to the bike.
ANY leaks there and you will be tuning and tweaking with no results.

I think form a gasket #2 is a poor choice I would use one of those rubberized silicone sealers like Permatex Ultra black or Great Stuff.

Its a start...

David

 

So I ordered some larger pilot jets on Monday and they arrived yesterday. Didn't look quite right, but thought I'd give fitting them a crack. My first impression was correct - the jets were the wrong ones!

Turns out the FCR35 is an older (and less common) N424-25 series carb with a thread of 4.5mmx0.75mm and length of 15mm. The far more common pilot jets that you see on eBay/RMATV/etc are for the N424-21 series carbs So if anyone in the future decides to fit an FCR35 please take note of this so you don't waste money learning the hard way.

Anyway, contacted Show and Go Motorcycles (http://www.showandgo.com.au/) who seem to be the only ones in Australia that supply jets for this carb and they had the ones I want in stock. Should get them early next week. The guy I spoke to seemed very knowledgeable and immediately familiar with the challenges of fitting the FCR35 to a KLX with starter motor. He reckons looking at a jet in the mid-50's range is the correct range at sea level. I ordered a #50 just in case I need to go 1 leaner, but also got a #55 and #58 to cover my bases 2 settings higher than the #52 I currently have installed.

At the end of this exercise I am going to have a nice range of jets - not sure if I will be able to sell them to try recoup the costs

Anyway, the up-side of this is that I won't be working on my bike this weekend so I can go for a ride

 

My FCR touches exhaust AND starter. It is a bitch to get in/out. I only use the pull cable.

not ideal, but ive ridden 1000's of miles with no reliability problems.

I might look for the "correct" spigots thanks to this thread..
I think the ball peen idea is great too, Ill give that a whack.

 

Arctra - I got both jets and spigots from Show and Go.... had to do my homework first using the Sudco catalog and help from guys here to work out what I needed.

 

I put it on Friday and went for a ride. What a difference. I now have second gear throttle wheelies. It was pretty much plug and play. Cables both had to be re routed. Carb fits fine. Its too rich, I ordered jets like what others have used because there is no sense in re inventing the wheel. These will get me in the ball park.

I opened up the pilot one turn, cut back the acc pump start and finish points and aimed the pump at the needle.

I have a bigger pilot jet (15), A smaller needle jet P4, a leaner needle and one main jet either side of stock.

Bike ran excellent once the carb was on. Snow and cold are holding me up from doing any more.

I saved about a hunnert bucks in the end over bills carb. His is probably jetted closer, but mine is bigger

I started a thread here.

https://www.kawasakiforums.com/forum...ad.php?t=34657


David

 

Well, I have spent the week itching to fit up the carb again with the #55 pilot jet, but put off doing it in the evening as I figured it was going to take a lot of fiddling - and I needed the bike for riding to work.

Anyway, got up early this morning (6am) to make the changes to the carb (2 turns out on the a/f screw to start with), whip the old one off, and fit the FCR35 again. Managed to sort that all out by 7:30, but figured the neighbors would not appreciate me firing the bike up that early. By 8:30 I couldn't wait anymore, so I tried to start her. Could hear she was close to firing, but needed a choke. Even pumping the throttle a bit to make the AP pump extra fuel didn't work, so I push started it. Fired up straight away - no mess no fuss.

After setting the idle I left the bike idling for about 10 minutes to see if it would stall once the temps got up, but it was fine. So already a big step up from last time. Took it for a good 10 minute ride, varying the revs a lot and making the AP work. She ran fine the whole way! Even when I got home and left it idling again it didn't stall, even though it was idling slower than what I had set it as when cold. Coolant temp was sitting around 70C, so I suspect when I do some single track and get the temps up in the 90's I will struggle with idling a bit. To be honest, I have been struggling with that on my CV carb anyway, so not much difference. An suggestions there?

On the test ride she ran fine under normal and hard acceleration, had nice mid range power (so I assume needle height is OK), and didn't seem to bog on acceleration (so I assume the taffy type mod I have done it pretty close). I did notice that there was a strange deceleration bog/hollow sound under some conditions, but I didn't quite nail exactly what was causing that, so have some more testing to do. There was absolutely NO popping on deceleration which surprised me. I know with the CV carb you will never fully get rid of the popping, but perhaps you can with the slider carb?

Anyway, I am going to wait for the day to warm up a bit (it's about 26C right now) as it's meant to be a hot day (expect 30C-35C temps) so will be a good chance for me to see how she does when it gets hot. Once I fine tune that, I need to figure out how to do the cold starting.

Any hints/tips on fine tuning the settings now would be welcome.

 

I would turn the pilot screw in 1/4 to 1/2 turn and see what happens. Always look for vacuum leaks.

Or just re adjust the pilot screw with warm bike, the idle speed you want.

I find if the bike idles faster when good and hot, (after a good floggin) its too rich.

Really glad you are using it. Any performance difference? CAN YA WHELLIE NOW?

David