Topic: Need help with my970cc project

[dragracer]

Uhh, gentleman, he needs advice on how to get the bike started. Or did I misread the first post.

[Medyo Bastos]

welcome. sounds like a nice build. with pics it would be even nicer
could be ignition timing off, try to advance it more

hope you also dont have cyls 1-4 and 2-3 wires crossed up... check it too by simply swapping wires to the plugs.

easy enough to tell if they are backwards.  motor will crank and you will get one big fart thatll about make you s4it yourself!

[awiertalla]

Just saw the pics added to the first post. The starter cavity is the worst possible place to mount a battery.

I've got it half way above the engine using battery foam so as not to over heat the battery.

[awiertalla]

I hope you add rear motor mounts..

This has been a concern of mine for quite sometime, and I didn't realize upon assembling the engine that on the 77-78 the final drive il seal needs to be set with the cases apart. I hammered it in afterwards and I know I'll need to pull the engine and remove the bottom case to replace it, so once the engine runs and I figure out any other potential issues, i will pull the motor and while doing that, add the motor mounts. My original intention was to use a stock 750 in this frame, so it wasn't as big of a concern at that point.

[awiertalla]

Just saw the pics added to the first post. The starter cavity is the worst possible place to mount a battery.

And the Reg/Rec and M-Unit mounted to the case leaves some questions too 

The M-unit is actually elevated above the cases. I used a 3/16 piece of steel and bolt one end into the crankcase, but the M-unit is hanging over and elevated about an inch above.

[madmtnmotors]

I didn't realize upon assembling the engine that on the 77-78 the final drive il seal needs to be set with the cases apart. I hammered it in afterwards and I know I'll need to pull the engine and remove the bottom case to replace it.

I've replaced several k8 and F2 750 final drive output seals without splitting the cases and had no problems (no leaks). The information you received regarding splitting the cases was wrong.

[PeWe]

I didn't realize upon assembling the engine that on the 77-78 the final drive il seal needs to be set with the cases apart. I hammered it in afterwards and I know I'll need to pull the engine and remove the bottom case to replace it.

I've replaced several k8 and F2 750 final drive output seals without splitting the cases and had no problems (no leaks). The information you received regarding splitting the cases was wrong.

I had the same thoughts before I saw video on youtube where the seal was mounted after cases were tightened.
I had no leak before and no need of replacing it. Ony when I opened the cases when all seals were replaced except for the one inside the aternator rotor that I changed when removing it and mounted it on another crank.

I'll change the seal if I'll get a future oil leak without open the cases. Maybe a little non hardening sealer that might help to slide in place

[Bill/BentON Racing]

Yah, batteries and electrical units don't like heat and vibration

[awiertalla]

I didn't realize upon assembling the engine that on the 77-78 the final drive il seal needs to be set with the cases apart. I hammered it in afterwards and I know I'll need to pull the engine and remove the bottom case to replace it.

I've replaced several k8 and F2 750 final drive output seals without splitting the cases and had no problems (no leaks). The information you received regarding splitting the cases was wrong.

This is helpful, I thought it was the same as the crankshaft seal that has a little lip on it and needs to be set with the cases. Maybe that will be one less problem I need to fix in the future.

[madmtnmotors]

I didn't realize upon assembling the engine that on the 77-78 the final drive il seal needs to be set with the cases apart. I hammered it in afterwards and I know I'll need to pull the engine and remove the bottom case to replace it.

I've replaced several k8 and F2 750 final drive output seals without splitting the cases and had no problems (no leaks). The information you received regarding splitting the cases was wrong.

This is helpful, I thought it was the same as the crankshaft seal that has a little lip on it and needs to be set with the cases. Maybe that will be one less problem I need to fix in the future.

Yep, the output shaft does not have the raised inner lip. The crankshaft seal (behind the points plate) does indeed have a raised inner lip, but there is an ingenious method for replacing this seal as well without splitting the cases. Takes some patience and a little intestinal fortitude for that one!

[scottly]

Have you been able to get the bike started yet? One of the things unique to the power arc ignition is that the wheel with the slots has to pass 1-4 TDC on power up, before it can generate a spark. A point system or a dyna will make a spark at either the 2-3 or 1-4 F mark, which ever comes first. This may be more of an issue with a big high-compression motor when kick starting.

[Big Jay]

Borrow a Dyna S to help trouble shoot it