Starter and Big bore

On a stronger battery try ballistic batteries. They have two different batteries that are smaller and lighter than stock. The 8 cell is 275 cca's and $159, 4.5x2.5x4.25 inches and 1.7 lbs. The 12 cell is 410 cca's, $189 and 4.5x3.5x4.25 inches and 2.4 lbs.
You might find them cheaper on Ebay.
Leo
 
Hi folks.... Very interesting reading for me as I am experiencing a lot of the symptoms mentioned so far. I have a 1971 xs2 with an 840 engine conversion based on the 'halco' spec. Electronic ignition which doesn't like any weakness in the battery. I think the starter finds it hard to turn the engine and although the battery is good quality soon loses power if the bike doesn't start and then it's all over.Theres also a lot of horrible noise when the starter doesn't mesh properly although I have noticed when the decompression lever goes tight it meshes properly.Compression too high to kick start.Bike always starts with a jump from a car 2nd or 3rd time ......... Thinking about removing the starter motor ( i have read articles about the engine/ crank being damaged by the malfunction of the starter motor and have found small metal debris stuck to the magnet in the oil filter) maybe then I could use the decompression lever to kick start?! Or something ludicrous like having another backup battery for the ignition system........ Bike runs great when it does start....... . Sorry to waffle on so much
 
What starter motor did you upgrade with?


grizld1 said:
Displacement: 700 cc. Compression: 180 lbs. Starting system: OEM starter only, kickstart removed (orthopedic issues). Starting issues: None, even below 30* F. Modifications: Upgraded starter motor and ground cables. Years in use: 4. Battery: AGM replacement for OEM unit. Bottom line: Keep everything clean, tight and tuned and the OEM starter will spin a 750 motor just fine.
Click to expand...
 
The work was not done by me and I,m pretty sure they put the original starter motor back in .... You wouldn't know the bike has been modified to look at it. I,ve heard that people who use them as flat track racers take out the starter motor... Partly to lose weight I guess
 
Hi gents.
My first post here :)

I have a Halco Tuning 1066cc monster that doesn't like to start.
I've just managed to put on a '74 decompression gizmo on the left.
Still battling.

She kicks back . Hard.

No go with electric start.

I've read that the harley guys use a pushbutton type decompression thingy, and managed to get one off a husqvarna chainsaw.

Is it at all feasible to install this on the right hand cylinder?
Apparently it allows you to swing the motor past one compression stroke and then automatically closes.

The idea being to start one cylinder, and then use that cylinder to start the other one.

The bike runs like a demon, if you can start it....

Any help appreciated.

I would even consider a second Yamaha xs decompression setup for the right side if I could find one...

Thank you
John
South Africa
 
I have used batteries from 190 to 210 now 220 amps. All three worked the 220 called big crank turns it over no sweat. 195 lbs. compression 750 CC. Bought from battery mart Manassas Va. Original starter.
 
The stock cables are not very heavy. They can't carry the load as well as heavier cables. They are like 10 or 8 ga cables. Upgrading to 6 ga will help . I shopped around the auto salvage yard and found enough cable to replace the positive from battery to starter relay, from the relay down to the starter and from one of the starter mount bolts back up to the battery negative.
The extra cable from the starter back to the battery bypasses all the joints in the starter ground path. Stock is starter to engine through the engine mounts to the frame through the battery ground cable. A bunch of connections. The extra cable is from starter to battery. Just two connections.
I have a 750 kit in my 75. I use the Ballistic Batteries 8 cell. It cranks easy now. 'Leo
 
What ignition are you running? Are you sure it's not too advanced for the start up?
 
I wonder if killing spark to 1 cylinder during the start crank process might help. Once 1 is fired turn on second cylinder? I am building a Shell motor at this time and it has no e advance. Timed at full advance 36-38 degrees. it uses an outboard starter off a bank of 12V car batts wired in series so you have 24V. Typical dragbike setup direct to crankshaft. I am curous how it will start, idle? Somewhere between 13:1 and 14: 1 compression 750 setup. There is no kick or onboard start components in the motor, removed for wieght savings. I would take the wieght with me if it had a starter onboard and worked.
 
Hi
Thank you gentlemen.
It's a newtronics.
Supposedly set up by a pro.
I will check that tomorrow.

I'm not sure how one would go about switching off spark to one cylinder.
Left cylinder has no compression due to lever being pulled while trying to start...
 
Well engine out, barrels off, measured bore 87.5 stroke 95
Compression measured at 150 psi
Blue button husqvarna chainsaw decompression button going in.

Wish me luck!
 
Good luck, while you have it apart could you take note of the internals being used..? Sp370 pistons etc, rods being used, spacer plate etc - thanks.
 
Thank you. Sp370 pistons is right, but theryre oversize.10mm spacer.
How would I identify the rods?
I must learn to post pics.
I'm taking lots
My maths tells me it's a 1142cc!
 
Do the rods have any markings on them at all..? Either 256 or 447..? Measure the rods centre to centre and also the size of the little end + if it's been bushed down. Photos would be great.
 
I am now rebuilding my motor which came with 87.5 Suzuki oversize sp370 pistons, and has a 95mm stroked crank.

Kicking is dangerous!

I have now fitted 2 husqvarna blue button chainsaw decompression valves in the head, and soon gonna put her back together. Running a newtronics electronic ignition, but am leaning toward one with programmable advance.

This is getting really interesting,and expensive!

X pipes, 38mm round slides, cutting rear section to fit a cafe seat, changing guages and wiring..

Love it!!
 
Thread hijackers!! Get back to E-starters and batteries and 750's!!!!

Sounds like a beast John, how the hell do you fit a 95mm crank in? The outside of the big ends must hit the crank cases, I'd love to see photos of inside the crank case where it has been machined out, and detailed photos of the crank and rods. You should start up a thread with some good photos and a few words on your monster engine, I'm sure everyone would love to see.
Cheers and good luck!
 
hijack..? - just nosey.....you want a hijack - ive got a pair of 36mm dells sitting here doing nothing....ha ha.
 

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