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?
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!
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".
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?
I would use a 38mm Lectron. I have a New in the box,if youneed it. Later Gary
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?
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[:p] 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!
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
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
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
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):D
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)
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
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!
(http://i24.photobucket.com/albums/c36/80fj40/marsattacks.jpg)
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)
I had a similar expeience as a teenager...a 1974 Harley Sportster, with a kick start only and the last year of a right side shift. I was in high school and about 120 lbs dripping wet, the cold winter starts were the worst !
I repeat what was said above, I had to kick it like I was meant it ! Both feet on the kicker and get it just before it explodes and give it all I had...I ended up on the ground a few times...but usually got it and or pushed it...course the compression relase did help !
Today, it is the little bore motors I like...they have even caught me off guard. A finely tuned machine will start...just mean business when kicking it over.
Victor
I just picked up my MINT this weekend...I've owned about 10 vintage open class bikes of both Euro and Asian persuasion -- and the MINT has the most compression my leg/foot/thigh has ever known. The motor is unbelievable.
A lot of it is compression, but a lot of it is the gear ratio on the kickstart mechanism is very "tall" on the KTM compared to most other bikes. For example, on my Maico a full stroke spins the engine over barely more than 1 revolution, where the KTM with a full stroke spins over 3-4 revolutions, which is why I ease it just past TDC so I make sure I get past that first compression stroke. This makes the already stout compression seem even more than it is, but if you get it past that first compression stroke it makes the easier to start.
Brian
'72 Berkshire
Guys...time to man up. The Mint 400 motors spin easier than CZ 400s, unless maybe the timing is too advanced.
Grab a step stool and put a boot to the '81 495. That'll make you a fan of the easy-kicking Mint in a hurry. Helps to be big though.
Quotequote:Originally posted by Big Mac
Guys...time to man up. The Mint 400 motors spin easier than CZ 400s, unless maybe the timing is too advanced.
Grab a step stool and put a boot to the '81 495. That'll make you a fan of the easy-kicking Mint in a hurry. Helps to be big though.
Or a nearby hill!:D
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?
Big Mac is right. In the early '70s I had E.C.Bert build a very radical and high compression CZ 400 for me, modified combustion chamber, reed valve, even had a Bing carb. I once broke my foot from the kickback on that motor, and I was wearing my boots. I have 3 CZ 400s now, all have motor work done to them and none of them are anywhere close to that E.C. Bert motor. In the late 1980s I thought I was done with racing and the vintage scene had not started yet. Nobody wanted that bike, so I dumped it into the dumpster. I wish I had that motor now. Hindsite is 20/20.
Lloyd
I agree with Big Mac also. The only time I have any issues with kicking any bike over is when I do not commit 100% to kicking it. Especially with big bores (two or four stroke) the key is to not be timid, the worse thing you can do is give it half effort, that is when they kick back and hurt you or break off the kickstarter.
Brian
'72 Berkshire
I'm with Kip.
Dave
Me too Dave. Base gaskets and lower compression are always bearable compared to Hip replacement... :(
Raymond
Down East Pentons
Here is a new method for starting big bore bikes. I have neer seen this before, but the video shows you how to do it. The guy is even wearing sneakers.
You can check it out here -
http://www.youtube.com/watch?v=FamfgXMW9Mc
I haven't tried it because I'm to old and scared. LOL
Tony
Tony,
I wish I knew that back in 1972 when I had my 3-man 450 Husky. It was a 3-man bike cause you needed 2 guys to push to get it started!
This is not needed with a Bing, when you blow in the vent tube you are just flooding the Mikuni like the tickler does to a Bing. Its a neat tip, but laying the bike on its side until it overflows does the same thing, thats what I do with the '79 Maico 440 that has a Mikuni. Works great.
Brian
'72 Berkshire
Brian,
Yes, that was the way we started our KTM's & Maico's when we were racing many years ago. Then, we found Lectron's. Trouble free.
Tony
Try that with my YZ490 and you'll end up with a very wet NGK and sneakers would leave you with a very sore arch. His RM did start nicely, with the Lectron carb.
1973 Penton Six Day
1973 Penton Jackpiner
1982 Yamaha XT200
1982 Yamaha XJ650J Maxim
1984 Husqvarna 400WR
1987 Yamaha YZ490
2005 Honda CRF450R
That is a flat slide TM Mikuni, it came stock on that bike.
Brian
'72 Berkshire
I wondered that after making that post, Thanks Brian!
1973 Penton Six Day
1973 Penton Jackpiner
1982 Yamaha XT200
1982 Yamaha XJ650J Maxim
1984 Husqvarna 400WR
1987 Yamaha YZ490
2005 Honda CRF450R
Maybe I am dreaming this but I think I saw an NOS "low compression head" for an MC5 400 on ebay a year or two ago. It went for something nearly 100 dollars. I'm backwards on mechanical details but I guess that it would make for easier starting (couldn't you just use different base gasket?). Maybe there is a better reason for such a head that is more to do with operational ignition/heat production.
Quotequote:Originally posted by Merlin
Quotequote:Originally posted by David Laite
"Try that with my YZ490 and you'll end up with a very wet NGK and sneakers would leave you with a very sore arch. His RM did start nicely, with the Lectron carb."
Better go back and take a better look, the RM has a Mikuni flat slide not a Lectron.
1973 Penton Six Day
1973 Penton Jackpiner
1982 Yamaha XT200
1982 Yamaha XJ650J Maxim
1984 Husqvarna 400WR
1987 Yamaha YZ490
2005 Honda CRF450R
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".
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".
(http://i52.photobucket.com/albums/g8/BobWardlow/kick.jpg)
Good stuff Rob, rule 2 also applies to your golf swing!
1973 Penton Six Day
1973 Penton Jackpiner
1982 Yamaha XT200
1982 Yamaha XJ650J Maxim
1984 Husqvarna 400WR
1987 Yamaha YZ490
2005 Honda CRF450R