'78 XS400-2E - pseudo project

[chulsmith]

Hi all,
First, thanks to all of the members of this forum who have provided insight and tips that I've been reading for the last couple of months. I thought I'd post pics, my list of to-dos and questions to which I haven't been able to find answers.

I bought the bike off of craigslist in running condition as I just wanted to ride for the summer and start on mods during the off-season (I'm in Minneapolis). After finding this forum and reading about how others are able to cold start their bikes on a handful of kicks, I thought 'I want MINE to do that too!' (sometimes took 20+ times!). That got me into tinkering around the carbs and engine (all completely new to me) from which I made my list.

My strategy is to get the engine tuned and then this winter, make some cosmetic changes.

The only things I've done thus far are (please forgive my lack of terminology knowledge):
Cleaned carbs (twice) and adjusted floats to spec
Tried to sync them but was told that's one of the last things I should do (http://www.xs400.com/forum/showthread.php?t=12827)
Checked compression (135 on each cylinder - a bit low? manual says 140-170)
Got new spark plugs
Checked gaps on the points
Adjusted timing (adjusted to the LF line but when doing the right side, the plate wouldn't adjust far enough to get it perfectly lined up with the RF line?)

It started cold this morning with only a few kicks so that's a win for me. Now I'm running lean on the left side - lots of popping and backfires when I ride.

To-dos:
Rejet, tune and sync carbs
Reset right side timing
Rear brake pedal on rare occasion kicks back at me so need to check that out
Check clutch - if I accidentally kill it, sometimes I have a hard time finding neutral

My questions are:
Is there anything I can do about the right side timing issue? I've moved the plate as far as it goes and seems like it needs to go a bit further.
I don't know what size my current jets are - is there a way to measure this or should I just buy a couple sizes up from stock? (I'm running pod filters)

I'll do some research on the brake and clutch issues as I'm sure there's something on the interweb about those things.

The cosmetic mods I want to do this winter:
New handlebar setup - probably clubmans - with new grips, mirror and controls
Maybe new gauges
New seat setup - the Sportster seat is comfy, but want to do something more brat-style
Get a tiny battery and relocate it - open up the triangle
Chop fenders
Remove chain guard
New foot pegs

Thanks again!

 

[Requiem]

Welcome to the forum!
To find out what jets you have now there's really nothing you can do but take of the carbs and take out the jets and see what number they are... When switching to pods and open filters you could try going up 1 or 2 sizes on the main jets, possibly 1 on the pilot jets (don't follow that size advice blindly, i'm hardly an expert)

 

[xschris]

Welcome to the forum. A lot of trial and error to get a modded bike to run right. Use a manometer for syncing the carbs. When you adjust the timing make sure you don't move the mark on the fly wheel back at all as it will put slack in the chain throwing off the timing. This also applies to setting the valves. Don't forget to do those also=)

 

[DARKMIDKNIGHTWARRIOR]

Welcome to the forum!

 

[chulsmith]

Thanks all. xschris, I think that's what I did the first time I set the timing. I went back and redid it yesterday morning and now is running the best since I bought it. I just can't seem to get the idle down from 1400/1500 not matter how far the screw is turned. Would this have anything to do with needing to rejet my carbs?

 

[xschris]

Sounds like it is still lean in the pilot circuit.

 

[chulsmith]

So I've been riding around town. Threw on some new handlebars and made some non-engine related adjustments. Now the idle has come down from the 14/1500 range to the normal 1200/1250 range. Seems strange to me, but I'll take it! When it's cold it sits at around 800 for a couple minutes but it quickly gets up to where it should be.

One of the problems I'm having is when starting it cold, it will sometimes take up to 15-20 kicks. Usually it's right around 10-12. After it's been warmed up, it starts on the first kick, maybe two. Any suggestions on how to remedy this?

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[xschris]

It is lean/dirty pilot circuit or the compression is low. A good tuned bike should start 1-2 kicks.

 

[chulsmith]

Thanks xschris - I measured the compression and it does seem a bit low according to the manual - it's at 135psi on both cylinders. How do I increase that to the range the manual suggests (140-170psi)?

 

[xschris]

New rings, valve job, gaskets.... I would look to the carbs/ignition system first. Make sure it is all set correctly and the carbs are synced with a manometer.

 

[chulsmith]

xschris - on your 1-2 kicks comment, is that with the choke on or off (for a cold start)?

 

[xschris]

Choke on. It is also good to prime the carbs. If you have a in-line visible fuel filter this is ease. Turn the petcock to pri(prime) and wait for the fuel to stop flowing. The carbs are now filled. Turn it back to on, pull the choke and start.