Topics

So 15 years ago I had an RZ350 and started to fuel inject it with a megasquiirt and some throttle bodies from an R6. I had it running and was about to start the arduous tuning process (i didnt have an O2 sensor) but I decided to get leukemia instead so that was the end of that.

Now I find myself yearning for a project to sink my teeth into and EFI popped into my head again. The plan is keep the airbox and use an O2 sensor this time to help with tuning. I have a 2004 700MXZ here I think I might sell to fund the project.

First thing would be buying a Vape ignition because I'd want the extra wattage it generates to run the fuel pump. I highly doubt the stock makes enough juice. Also there is no coolant like the RZ but I'm fairly certain people run those spark plug head temp sensors and alter the tables in the code to adjust mixture as the bike warms up. I have 10ah liFeP04 cells and Id use 4 to build my own 12v battery to make sure there's plenty of juice if I ever get caught in stop and go traffic. The Megasquirt has ignition map capability but I dont think I'll go down that road for fear of melting holes in pistons. This will really just be a project to keep me busy and interested over the winter.

I'm still a little on the fence if I take this on, tho.... im trying to save a down payment on a house and heading down this road will easily cost $2000 if not more. Im telling myself if I sell the sled its money I wouldnt have had anyways so.... its ok to spend it on this project.

If I do go down this road... there is still time before the snow to order a Vape and get that on and running. Once thats done everything will be in place to start EFI build.

Am I crazy?

Hey guys I just found a pair of stock pipes from a canadian RZ350 I had... is there a market for these things?

Thanks again

Hi guys, long time no chat! Hope all is well with everyone.

I wanted to ask about my jetting... my 76 RD400 you all helped me rebuild from the tires up runs super well. I must have made 50 jetting changes to test everything I could and landed on my current set up. I know I ended up on the rich side but it's the only way I could get it it not surge at stead throttle at relaxed paces and also I run the bottom rich so it doesnt buck when I shut the throttle to start slowing down. If I open the air screw just a 1/2 turn from where I have it then it starts to bucks on decel.

Around town it's fine and at city cruising speeds it perfect but when I start to roll the throttle open to get up to near hwy speed is starts to noticeably smoke. Not a thick cloud, not that bad but more of a haze left behind. Same when I open it 100% to accelerate on the hwy it does this, but more so. I run premix at around 45:1 if I recall correctly. I'll have to check that little container I use when I fell after hitting reserve.. but it doesnt seem to be too much oil when just bombing around town... i dont really see any smoke at all. jusrt checked... its 8.5oz or 250ml that pour in when I fill and it takes 13.5 liters

Am I right in thinking that if I lower the main jet size I will not only lean out WOT but it was also lean out half throttle and up?

Picked up a 2001 MXZ 700 in very decent shape. Just need to replace the clutch with a used one from fleabay and it's good to go. Motor is STRONG which was really my main concern. Thankfully, with all my experience with our RD's and RZ builds over the years, I wasnt blind going in and knew what things to look for.

It's a 121" inch short track with less than an inch lug on it and a wide ski stance... it's made for hard pack trails and it shines on them... but I like to go off trail every chance I get so the plan is rail extender to 136" for more floatation in deep snow and a 1.75 paddle track 'Backcountry' that should make this thing miles more capable in the powder. I'm also going to shorten the radius arms and steering rods and bring the skis inwards 2" a side and will add a 6 or 8 inch bar raiser which will allow me to rock the sled from side to side easier.. very useful in the fluffy stuff. I'm also removing that seat and putting on a smaller lighter one from a Polaris.

Once all done I will have a very competent sled off trails for 1/4 of a new sled of the same type and power.

Hi guys,

I'm about to start to disassemble the RD400 for the winter the go through the motor and make sure I did everything right during my rebuild last winter and also to send out cyls and head for squish correction.

From quick older check Im getting 1.3 ~ 1.4 mm of squish. I am just wondering if I use a thinner base gasket to drop the cylinder say .4mm would i notice any difference in low and mid range power? Id have to watch my compression of course.... i think it was 140psi the last time i checked.

Thoughts?

Hi guys,

I'm just wondering how a machinist goes about centering the dome perfectly to be able to drill and dowel it?

thought youd guys would enjoy this pic

Happened to come across this site that offers a stubby looking 2 into 1 system further down the page. Anyone ever heard of K2 Tec?

http://www.moto-works.jp/k2tec/rd400.html

Hi everyone.. hope youre all good and had a good summer.

I like my bike to be stock but the one thing Ive always wanted to do was get the squish corrected. I'm hoping for a little more oomph all over... I assume thats what would happen. I dont imagine it will be a big difference but every little bit helps on a stock bike. Anyone had this done and what benefits did you see? Wonter is nearly here so it would be a good time for me to have it done.

Also, I seem to remember someone here offers the service... i cant remember who though?

John

Hi everyone,

Hope you are all having a decent summer.

My 76 completely stock rd runs fine but something I have always noticed is that the left exhaust pulse is a strong POP POP POP without skipping a beat while the right side seems to be 2 little pulse per the left's, one.

I thought it was the exhaust baffle because i ordered a new one from the UK but recently I took them out and they look identical so I swapped them but the exhaust pulses didnt switch sides.

I checked timing with the timing light today and neither side has moved. Ive messed with idle screw and air jets on one side and not the other and cant get the pulses to be the same. I also tested for air leaks again and there are none.

I'm going to swap the carbs next to see if the issue switches sides as well....

Anyone ever seen anything like this?

Hey guys... has anyone run the stick needle on the 2nd clip to lean it out one notch on a stock set up?

I have all stock except the oiled air filter and i run a 25.7 pilot (stock was 50) and a 140 main. I run the air screw at 1/4 out otherwise it bucks like mad when i close the throttle. I think my current setup causes the 1/8 to 1/4 throttle to be too rich and i get that burbly spot between 4 and 5000 rpm on the hwy and bombing around town.

Is leaning the needle something one can do to clean up that area of the rpm at steady throttle?

Hi guys,

I drive from Ottawa to a town exactly 100 km's from me and it takes 8.5 liters. That leaves 2.5 liters before reserve.  That leaves  29.5 km's in the tank for a total of nearly 130km's per tank in the hwy..

I'm almost 100% sure that driving around town I can get to 160km's easily.

Is it possible that HWY driving at a steady 5500 rpm (100kmph) can suck more gas than bombing around town and talking it easy?

Hey guys,

I notice when im on the hwy at steady speed and not speeding... there is smoke coming out of my bike. I really notice it at night because the clear underside of the brake light illuminates it. If I open the throttle more to accelerate it increases the more i open it. I am running around 40:1

I know my bike is rich because I only run the air screw at 1/4 out because it really prevents the closed throttle bucking and surging. The needle is on the middle clip and I have 150 mains.

What ya think? Am I way too rich? The bike runs smooth and its not fouling plugs, yet, but... could it be running much better?

Thanks again,

John

Hey guy,

Yesterday I decided to install the HPI. Everything seemed to be ok. The bike started up but needed some extra idle screw.

1st issue is it is not charging the battery. Voltage at battery does not change at all when running or stopped.

I floated the ground and connected it to the r/r as showing in my work of art below. Is that correct?

Check this out.. a good watch.

https://www.youtube.com/watch?v=EZG6EBakNfs

I ordered a seat cover from Econocycle and am getting ready to remove the old one and put this one on. I've never done anything like this before and I want it to look perfect. There's also a strap included but I'm not sure how its supposed to be attached and to what.

Any tips or tricks to get it right?

While i was making sure i wasnt melting piston tops with all my plug chops i discovered my right cyl looks not good compared to the left that looks perfect.

I think I know why... when I was putting the rings in the pistons for this side  i bent the rings an imperceptible amount. The entire ring would just fall into its groove... it would get hung up a but but a light push could get it in. This was the only thing that was difference when putting the two sides together.

Would a ring that cant move freely cause what I'm seeing? There's even places that cross hatching has been worn through... especially about the boost and exhaust ports. All ports on both cyls were chamffered by me.. and the left shows zero wear above ports.

I've order a hone and some NOS Yamaha rings like the ones that came with the pistons. If I give a light hone and replace the rings... should I be ok?

Hi guys,

Any ideas on how to stop my front brake pads from moving around? I can hear that little tabs on them hitting the caliper at lower speeds.

Rubber band maybe?

Just picked up the bike from having dropped it off for a safety certificate. Tomorrow I will go to get it registered and get a plate then I'm all legal.

Funny thing.. I was getting my truck bed ready for the bike when the owner of the shop drives from the back on my bike and parks it beside me. He says "nice little bike" then tells me that if I ever choose to rebuilt it... it would be worth nearly 10g. Of course I was like "rebuild it?  I just sank 5 grand in parts and 6 months of my time into this bike." then i realized the bike looks like its been around for 44 years so I relented and said "paint job and powder coating next year"

Hey guys,

Just wondering if anyone has another option for the shifter return spring? On my bike it is needlessly strong. It is actually starting to hurt the top of my foot/toes while bombing around from light to light.

Are all RD400c's like this or has someone put a different one in my bike during its lifetime? Weird thing to complain about but gawd damn its a strong spring.