V30 Magna issue

A

AntonL

New Member
Not sure what the issue is but my V30 Magna all of the sudden started running like crap. It idles like a dream but starts sputtering and acting up when you give it throttle. It feels hugely underpowered too. I've changed the plugs and wires and cleaned out the carbs. All diaphragms are golden. Fuel pump and filter are fine too. It ran fine the morning it started.. rode it to class and an hour and 20 mins later I fire it up and it does this.
I'll post a video of what its doing in a few minutes as well.
 
The bike has been a several month cafe project and started acting up as I was getting ready to post up by progress on the thread. It's a sweet little 500cc V4 for anyone unfamiliar.
Anyway, I'm going to do a compression check tonight to hopefully rule out a major engine issue.
I'll have numbers up tonight.
Thus far I'm at a loss
 
doubt if you have an engine issue from your description....if carbs are clean sounds like you have an ignition problem.does it get worse hot? battery cables tight? replug all ignition and power connectors. ck coil resitance- pri/sec....joe
 
Sorry it took a bit longer than I hoped to get the tester.
Numbers are as follows as if you're sitting on the bike:
Left rear - ~99
Left front - 110
Right rear - 115
Right front - ~95

The ~ means it was in between and its my closest guess. I'm using an analog tester so its not 100% exact.

I didn't open the throttle for it so I will be redoing it. Clymer says it needs to be 142-199psi.

Throttle wide open with cold engine

Left rear - 120
Left front - 115
Right rear - 120
Right front - 105
 
Compression is a bit low.
Probably picked up some dirty gas?
Have you cleaned carbs?
They are a total biiatch to get on and off, made me dislike the V-4 Honda's intensley (although the 500 isn't anywhere near as bad as the 750/1000/1100)
 
Carbs have been cleaned. I made a custom air filter, ugly but gets the job done and makes the carbs SOOO much easier to take off. I plan to go through them again just to be a little more sure. I thoroughly cleaned them a few months back but maybe something happened since. I was an idiot and ran them with no filter till I made my own so I'm worried I may have killed the engine in that time.
 
If it was running fine then bad after you stopped for a while, I would suspect bad fuel more than anything else
 
when did you fill up? same gas station or just anywhere?
If carbs come off easy, you may have manifold leaks as I seem to remember they are angled and never easy to fit or remove
 
I drained the gas and put fresh 92 octain from 76, always had best performance from them. I can't remember where the gas was from inside of it.
It seemed to run a lot better after the previous stuff burned off. But when I took it out for a spin a oil leak I thought I had fixed came back and seemed to run like crap. It's from the clutch push rod. It seems bad enough now that I think I'm losing significant oil pressure. Can that be the issue?
 
only if the oil level is low enough to let cams or pistons seize.
Pressure gets to the transmission last
It's not a big deal to change push-rod seal
 
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