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Acceleration Problems following service

Discussion in 'Technical and Troubleshooting Torque' started by dougster, Apr 16, 2007.

  1. Last week I left my 1990 yamaha FZX250 (commuting bike) with a mechanic for a full service + carburetter to be tuned. I've got it back, now it doesn't accelerate up hill properly - hits 6-8krpm (if that) and flattens out even in lower gears. Then If I try to drop down gears, it stalls as soon as I pull the clutch in. It no longer takes corners uphill happily either.

    As soon as there is any load it seems to struggle maintaining speed. I seem to be operating the throttle flat out where I didn't before. The other thing I noticed is that sometimes the idling sound appears to pulsate - with the occasional rapid jump in speed. I run the bike on premium fuel if that makes any difference.

    Can anyone suggest what is wrong? has the carburetter been setup incorrectly? or is the fuel pump failing?

    everything else seems fine.
    Would greatly appreciate any thoughts on what has changed before I ring them up and complain.
  2. Before ringing the mechanic and complaining.........check for any vaccume leaks. (hoses disconnected airbox not sealed) Up and down idle is an indication of this and could also explain why its stalling as it could be running way to lean.
  3. someone screwed the carbies up ;) or as suggested left off a vacuum hose
  4. Have a quick look for something stupid. As suggested, vacuum hoses and fuel lines.

    Make sure all the plug caps are seated properly.

    If all that is good, then take it back to the mechanic. I'd bet (if above fails) they've played with the carbies, then didn't do a balance.

    they will probably be embarrassed enough to fix it right up for you.
  5. mate bring it back to them. they must have put it back and somehow clamped a vaccum hose or did not do the carbs proberly.
  6. I had a look last night and everything is where it should be. Is it possible that the carbs have been tuned at the wrong revs for my riding?

    With that said, can the carbs be tunned to suit a particular persons use of the bike or must they match the factory settings?

    I think this is the last time I will visit a mechanic other than for having my tyres changed. I've also noticed that the throttle now sticks hard when the steering bars are turned to the right. Last week, an L-plater mate of mine was allowed to ride home on a bike that had no locking pin on the back axial. I'm beginning to thing this trade is getting somewhat sloppy. - a different mechanic again and both trusted.
  7. Carbs should be tuned right for the bike. Nothing to do with the person. Synchronization of the carbs does make a big difference. If they forgot to do it, or just were sloppy, then you will notice it on a small capacity bike.

    And yeah the industry is pretty slack all round. there's a lot of disgruntle mechanics out there who got into a job they now don't like and most salesmen are tools. Add to that some pretty poor policies by most stores and it's hard work sometimes.
  8. think you are right...rang up today to lodge my protest and got quite a sympathetic response. Not to sure how it will go given the mechanic said he was all booked out but will take a look Mon next week.

    I like the guy, he is honest, but I don't like the idea of running too many jobs at once - I know for a fact he got side tracked when working on the bike last time...and that's probably how he overlooked synchronizing the carbies correctly. I showed up unannounced at the workshop on the day I was supposed to pick it up only to find it in pieces, and nothing had been done...was disappointed given he had had it there 2 days and I'd already done most of the work.

    Will spare my $$ and buy a set of vacuum gauges next time.
  9. +1 well worth it[/quote]