Ok so i had my top end done

i had 1980 maxim xj650 engines top end done, compression check and turning was fine, remounted the engine to the frame last night. when i hit the Start button i get a GRRR type noise, but when i pull in the clutch , it will turn over and idol beautifully. sounds so much better than my old one. BUT when i put it in gear and gas it a lil , it doesnt spin it just craps out. any ideas ? my mechanic who did the job is out of town for a few days so im kindaf****d with beautiful weather, a fully redone bike and a major hunger for wind in my face

***Mind the language! Thanks, Robert***

 

Side stand saftey circuit cutting the engine out? This circuit will cut the ignition when the kickstand is down and not in neutral.

 

Looking at the schematic, it does not look like the 650 Maxim's had a side stand safety circuit. The only safety relay is a starter interlock relay that's looking for Neutral or Clutch Lever In in order to start.

Sounds like a fueling problem or some other carb problem that you're running into.

 

carbs are fine it gets fuel, I put key in, turn it to on, hit start button, and it goes grrr. i pull in the clutch , it turns over and runs. but if i let go of the clutch and goto gas it , it'll bog out and shut off

 

The XJ650H does not have a side stand relay, at least according to the Haynes schematic. But the J and K do have the sidestand relay. Yours is an H.

Easy thing to check visually though, just look at the pivot point of the sidestand and you either will or won't see a horizontal safety switch.

Regardless,

If it was a safety relay, and you had it in neutral when touching the starter button, you would not get a GRRR type noise, you would get silence.

Once running the safety interlock is no longer looking for the clutch/neutral switch combination. But it could be a possibility.

However, I would suspect fuel delivery as the first culprit.

The easiest and quickest thing to check is a blocked fuel cap vent, so start there.

Open the gas cap and try to re-fire the engine. If it still happens then we go on to the next item on the list, which for me would be the vacuum line.