new prob - slow throttle response but RPMs rising

hi -

new issue with the ol 82 maxim 550. i'm sure there is a term for the problem but i don't know it so i'll just descibe it. when riding and i give it a throttle quickly it kind of 'slips' - rpm goes kind of high/engine gets loud, and the bike barely accelorates. if i give it throttle slower it takes off ok, but not when i really pull. its a little worrysome when i need to accelerate quickly in traffic. is this 'misfiring'?
will i need to fix something with the throttle? or maybe the clutch? is this a common problem? my motorcycle adventure continues ... thanks - nathan

(and thanks for responses and help considering i haven't offered much back)

 

Re: new prob

I may be reading this wrong but it sounds like you have clutch slip...
May need new clutch plates.


But I may be interpreting this wrong?

 

Re: new prob

Sure sounds like the clutch to me.
You can get new disks at www.partsnmore.com I think. I can for my 650 anyway.

They also have the clutch springs too.

 

Re: new prob

I'll echo clutch plate slippage. Time to rebuild it.

 

I agree with SnoSheriff, check cable adjustment first. Also what kind on oil are you running? If it has friction modifiers in the oil, you will have this problem also, as the clutch plates are in the engine oil.

 

Well it appears I haven't offered much either. Seeing how I jumped the gun on my response and said go straight for the clutch. Sorry, I should have known better. Always go for the easy/simple stuff first.

Thanks guys for setting us straight.

 

I have to disagree amicably! If the rpms are not rising seperately from speed, I would discount a clutch problem.

This sounds like the problem I had when one of my spark plug wires became detached from the spark plug cap. Essentially, it was running on three cylinders. It would raise rpms, but very slowly.

Maybe check your spark? Maybe a carb problem where one cylinder isn't getting fuel? Maybe synchronizing would help?

 

thanks for the additional suggestions.
i'm late in responding here so everyone may have forgotten about this post, but in regards to richard's suggestion to check the spark, i think the rpm IS rising seperately from the speed (maybe i'm wrong). i give it thottle the it takes off some and then all of the sudden rpm will go high and bike will barely accelerate. so that may not be it??

i've fiddled with the clutch cable, on the handle bars and by the crankcase, but i'm not sure what i'm doing, just sort of turning it. i'll try that again.

 

Yeah, really sounds like clitch slip to me. An unscientific experiment might help you confirm it. To intentionally induce slippage, while cruising or accelerating slightly (when it's not slipping), give the clutch a very light, gentle squeeze (just a few mm) - does that replicate what's happening under heavy load?

As for clutches, mine seems to be getting towards the end of its service life (with slack in the cable, i don't have to pull very far for it to slip). I've tried a few different oils and found one to stay away from but the rest ahve been about the same as what I have now (Yamalube 4 as specified in the book). What kind of mileage are folks getting out of the original clutch? I'm around 26k now - seems I should get more, but you never know.

 

Sorry, I may need to work on my reading skills!

 

Zounds! I thought I mis-read the original post looking at the last round of comments here. One thought about the slipping clutch. As I understand your problem, you accelerate the bike, the rpms go up but the bike doesn't move along as it should. If that is the case, you need to get a new clutch pack (make sure you get new springs too) and rebuild the clutch. Fairly easy task with the Vise Grip tool. Get the tool and your on easy street. Hope your back up to snuff soon!

 

many thanks all, i'll try a little oil but probably just need to rebuild the clutch. fairly easy to do? where can i get a new clutch pack (with springs)? is that something i'll need to order?

 

Before doing the cluch, I would change the oil with Rotella 10-45 and see what happens. I use stuff with friction additives and I have never had slippage, but that may very with clutch age and driving style. I have talked to lots of people who have problems with it.

 

Easy is relative, have any experience with tools? If so, I think you should be ok with a service manual of your choice. Several suppliers are available, Dennis Kirk, Chaparral, K & L, the list is fairly long. Do a little looking and I'm certain you will find the needed kit. I'm going to agree with Phred, do the simple (read: Cheap) things first. Have you done an oil change already with a non-energy conserving oil? I'd start with that and proceed only if it doesn't pan out. Good luck to you!