Starting a MC5 400

[Britt Boyette]

Is their a trick to starting this big bore beast? Maybe I need to add a compreeion release or a big hill. Also, which is the best carb for these engines? It has the stock Bing on it now but would a Lectron or Mikuni be a better choice for performance?

Britt Boyette
76 400 MC5 (project)
77 250 MC5 (uberproject)
77 Husky WR250
75 Can Am (future flat tracker)
76 RM370
75 Hodaka Road Toad
83 YZ250
Too much of a good thing?

[marsattacks]

Here's what I do. Works well for me. Flood living daylights out of Bing Vergasser. Two or three primer kicks (easy w/ finger on kill button). Then a good proper kick all the way through w/ a crack 'o gas. Lights up like a maniac machine almost every time.[:0] I'm 6' 205 and it takes a good solid effort. Even better if you can be on a curb or something. I'm thinking of a Lectron swap-out since I lug it and the Bing doesn't like that too much. Too much bike for me to ride it properly I fear.   Good luck!

[Merlin]

Try this, gas on- open throttle full- hold tickler down until you see the first drip of fuel- gas off- throttle open about 1/4- piston just at  tdc- kick firmly- engine now running

Quote: Thomas Jefferson, We are all born ignorant, some work to remain that way.
 Quote:Peter Villacaro, "it is impossible to teach those that wish not to be taught".

[Britt Boyette]

If you ran a Lectron, do you have any idea which one and which needle you might use?

Britt Boyette
76 400 MC5 (project)
77 250 MC5 (uberproject)
77 Husky WR250
75 Can Am (future flat tracker)
76 RM370
75 Hodaka Road Toad
83 YZ250
Too much of a good thing?

[G Ellis]

I would use a 38mm Lectron. I have a New in the box,if youneed it. Later Gary

[Britt Boyette]

Gary, I've sent you an email.

Has anyone ever installed a compression release on one of these? I see that they have a boss molded in the back of the cylinder but it looks like you have to drill the hole out first.

Britt Boyette
76 400 MC5 (project)
77 250 MC5 (uberproject)
77 Husky WR250
75 Can Am (future flat tracker)
76 RM370
75 Hodaka Road Toad
83 YZ250
Too much of a good thing?

[Kip Kern]

Britt

I have had a "76" MC 400 and currently own a "76" GS 400.  Each had no compression release and usually started with the 2nd kick cold and 1st kick warm (I can start the GS sitting on the bike using my left leg).  Both used a 38mm Bing with standard jetting.  I use the choke wide open, tickle the carb until fuel runs out then kick and she starts pretty easy with no throttle.  Once warm after a second or two, remove choke and hold on[]  The MC will stretch your arms and the GS will dig trenches for planting!  Check your ignition/coil grounding, stay with the Bing, check your float setting and jetting it works fine!

[gooddirt]

Britt's new bike was my old mc5 400 as of last week. The only way for me to get it started was to loosen the spark plug and act as a compression release. The bike has so much compression before I did this it snapped the kick starter. After its started and warmed up a little bit I tighten the plug ; it will start in a 2 kicks after that. As I think now could the deck height be set to high for all of that compression?(or do I mean to low ?) Now only if I could get the bikes little brother started. LG

[brian kirby]

I am 5'7" and 140lbs, so this is how I start mine.

Tickle until it overflows, carefully ease the engine just past top dead center, KICK LIKE YOU MEAN IT! It never starts first kick, so repeat same procedure, including tickling and inching past TDC. 9 out of 10 times it starts on the second kick. The single most important step for me because of my size is getting the piston just past TDC just like starting a big four stroke. The engine has so much compression if I try to start not barely past TDC it wont get past the compression stroke on the next revolution.

Brian

'72 Berkshire

[Steve Minor]

Ever had one start...only to find out it's running backwards?
I have and it's not fun when you let the clutch out!



Steve Minor
Wilmington, NC

[Kip Kern]

Motoplat 2.4mm BTDC timing.  Deck height depends on piston manufacturer, I usually go long/max for less compression and easier starts (longer life of piston too)

[tomale]

Hi steve, yea I have it did that the first day when I was at the Tulsa in 04 for the ISDT RR it sounded fine until I let out the clutch, boy did I feel dumb. I think it happened as a result of a back fire and then it started. Timing was fine so it is the only thing I could figure. Never really had much trouble starting my 400 but then I learned along time ago to not be afraid of the kick starter.. timid translates into kick back...and pain

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)74'
250 hare scrambler (project bike)

[David Laite]

I learned this method early on my YZ since it oftentimes wants to retaliate against the rider, at best you get 1/2 a crank rotation from a single kick, nasty compression so you actually kick the kick start from about six inches above at tdc, slightly crack the throttle and it
usually fires. A buddy with a quad and a tow strap is a good backup method.

1973 Penton Six Day
1973 Penton Jackpiner
1982 Yamaha XT200
1982 Yamaha XJ650J Maxim
1984 Husqvarna 400WR
1987 Yamaha YZ490
2005 Honda CRF450R

[marsattacks]

You must have the cylinder with the horizontal port for the compression release. They also came with two-plug heads, which is what mine has.  I plan to put a compression release in mine (typical plug-sized).  The horizontal port takes a special size compression release I believe so you might need to investigate.  It might just be easier to find a two-plug head.

Mars Attacks!

[tomale]

you do need to be careful the compression release does not go too far into the cylinder.. ie, when compressed it does not interfer with the motion of the piston.. what I did was add a spacer to the compression release and then I added another little spacer inside of the release itself to make sure it opens but not too far....

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)74'
250 hare scrambler (project bike)