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I swapped out the pilot jets yesterday and went for a quick boot around the block. /I was looking the bike over afterwards and noticed that there was no oil in the oil line feeding the left cylinder. It was a few inches back. I'm guessing it dripped out while I had the carb out. Now I'm thinking ive scarred the sides of the piston or rings. I'm going to removed the head and have a peak at the cylinder walls to look for transfer but I wanted to ask....

Whats compression supposed to be on a stock RD400c?

Got my new exhaust baffle from UK.. took a month to get here. Bike sounds perfect now. Not done jetting but it runs really really well so far. I still need to do 1/2 and full throttle plug chops... and I'm still uncertain if I will go to a 30 pilot. Running the 27.5 right now at 1/4 turns. The rpm will speed up if i go to 1/2 out but i put it at 1/4 because its still cool here and I just want it richer for now. No weird behaviors... just pulls. I havent been to redline yet while wot either but i do bring to it 6 or 7 once in a blue moon just to give a go.


https://www.bitchute.com/video/bzzTVjOQbfIc/

I need a speedo with kmh's on it.  Will the one's from the F fit in my C? They look identical to my eye.

Thanks again,

John

Just wondering if thats normal or could I have not worried it correctly in the headlight bucket. I have LED head light and tail lights but the turns signals are normal bulbs. I can easily see the head and tail light dim every time the turn signals flash on. There's no way they little bulb is dropping the voltage like that on a freshly charged batt to cause the other lights to dim a little.

Any ideas?

Hi guys,

I managed to get the RD400c together enough to drive it up and down the street fumigating it.

I have 27.5 pilot (stock 25)  5L1 needle on middle clip and 120 main (115 stock) and 1-1/2 out on air screw. Bike started right up and ran 'ok' in the little jaunts I did in 1st and 2nd. It seemed rich to me so I leaned the needle 1 position. Very nice improvement. Wanted to wheelie even more so and it felt like it wanted to in 2nd. But of idle it didnt feel as good since i leaned it out.

Everything is 100% stock aside from air filter element. I kept the bottom plate with the two venturis and sat a trimmed uni filter on it.

Question is... is it possible my bike wants a 30 pilot even though the stock was 25?

Hi guys,

Is this correct for the rear brake hose routing? The hose wanted to go on this way naturally but I'm not keen on the hose being higher than the caliper and catching air in it. Should I flip it?

Hey guys,

Im a little worried i might lose out on the hundreds I spent on renting the cabin in Fontana. I have a feeling that this stupid covid-19 issue is going to mess up my travel plans 7 weeks from now. If I cancel now I can get some of my money back.

Am I being dramatic?  lol  If I do cancel and it turns out travel is ok in 7 weeks then maybe I can still get a place to stay in Fontana.

My other concern is I had a bone marrow transplant 15 years ago because I was diagnosed with Leukemia.. my immune system isnt lousy but it's not 100%. Depending on how much it spreads it might be risky for me to really go anywhere 

Not sure what to do!

As I was looking at wires trying to sort my signal light issue I noticed a connect tuck up under the frame that was loose. I see where it came from and pull the module out. I cant find anything like it in the wring schematics I see online. Anyone know what this?

please see video I made... right side signals stopped working and i have no idea why. Bulbs are not burnt and no wired i can see are loose

https://www.bitchute.com/video/JuaovQjMMN89/

Hi guys,

Just need to know the size of the hose that joins the tank halves
the size that goes to the carbs from the tank
and size for all the venting hoses from the carbs that head to past the swing arm and point at the ground.

Also... a good idea to separate the tank halve tube without it spilling all over the effing place. A good quality quick disconnect maybe?

Thanks again

John

Just curious... is it normal for an RD400 to smoke like a chimney with premix at 32:1 ?

I have a 27.5 in there right now instead of the stock 25 pilot so maybe that's why?

Thank you,

John

Hi guys,

I am currently disassembling the top end so I can check right end gap and have a peek after it ran for 3 minutes for the first time (cyl walls and piston look perfect) and I noticed the a couple sides of the base gaskets had oil on them. I'm not sure if that happened when i was taking stuff apart... things were defo wet in there because its rich right now.

Is 15 ft/lbs really correct for those headbolts on the RD400 ?  I only ask because when torquing them I remember thinking "that's all? doesnt feel like much". Mind you, my torque wrench is long and perhaps the leverage made it feel that way.

Is it safe to go higher if I feel the need?

Thanks for everyone's help over the last few months. I got the bike to a point where I could start it. No chain or brakes yet... lots of wire placement stuff to do but it started on the third kick after being in a million pieces. Its on premix at a little more than 32:1 which is what I run in my YZ125 so I just went with that. I still need to finish priming the pump and all that. I put the stock points system on it at 1.8 btc even though I have an HPI ready for it. I wanted to get it running as good as possible 100% stock as it was when it was sold before changing the iggy. I want to feel the different between the two. I still need to get a proper exhaust baffle for the one side... I have no clue where the one that's in there is from.

One thing I noticed at this ultra early stage is the bike quickly settles into idle after a blip of the throttle. All my other 2 strokes never did that remotely as quickly... probably because they all had air leaks and I never knew it. This bike got the leakdown treatment.

https://www.bitchute.com/video/vSc0w1C73SGS/

Hi guys,

When I put all the bolts in there is this perfect gap all the way around the rubber joint. I checked the old ones the bike had and they are the same length as the ones I got from Yambits.

If I remove the bolt near the front of the muffler near the foot peg I get move it forward and close the gap as the hole for the rear mount near the wheel is oval and allows for adjustment. But... with the other bolt in it... there is that gap. The exhausts have 1A1 stamped on them so I think they are the correct ones.. I wonder if the headers are not originals.

I think the only way I can remember this is drill out the forward mount hole on the exhaust and make it oval as well so I can shift it all forward.

Anyone seen this before or have any ideas why I'm seeing it?

Also... those aluminum inserts that Yambits sent dont seem to want to fit into the mufflers... am I supposed to press them in?

Thanks guys

Hi guys,

How important is it for me to measure the ring end gap on these OEM rings and matching OEM pistons? I cant find my damn feeler guage.

Me again!

I was trying to get a little ribbon spring out of the piston ring groove and ping... it went flying and has disappeared into the ether never to be found again. It goes under the lower ring. I've never seen these before on the Wiseco pistons I am more familiar with. Can I just omit the other one and run like that or am I asking for trouble not having it under the ring?

I see on ebay ring kits with the exact same part number that dont even have a spring so I am wondering how necessary they are for a stock bike.

John

I pulled out the other exhaust baffle today to burn the carbon off it and discovered it isnt the same as the other side.

Which one is the correct one for 76 RD400c? That one with the shorting thin section doesnt have any perforations in it like the other... its just light passing through the other one onto it.

And, where do I get the correct one from?

Thanks again,

John

I did a search but couldnt find everything i needed...

Ive drilled out the brass balls on my carbs for my 76 RD400c to be able to clean out the jests behind them.

To tap them I only go in a few threads correct?

What size is the tap and grub screw?

Also the stock jetting for this bike was 25 pilot and 115 mains.

I cant find where it was suggested but does 30 pilot and 120's sound like a good place to start?  It is bored 1mm over and 100% stock everyhting.

Just went to take the rear brake caliper apart to check its state and it seems to be seized. I took my air compressor with 90-100psi in it and used that and the cups wouldnt budge at all.

What are my choices?  Ebay or Econco?

Dont kill me for asking but which way do the for seals go in?  The large gap side of the seal inwards?

Thats what I suspect but after some of the dumb things Ive found on this bike I wanted to double check.

John