Subject: Slow to get going Wed Oct 07, 2020 8:35 am
Good day friends! I am in need of some advice/suggestions on what might be causing the problem I am experiencing with my GRiSO. As of my last few rides, I've noticed that when taking off from a stop, the bike is slow to get moving. Usually it's around 4-5K rpms before I really get some acceleration going It no longer has that initial torquey response like it once did from a stop. I also noticed that once I'm up to speed in say 3rd or 4th gear and I go to downshift, there's no overrun (I think that's the term) which seems really odd. The bike shifts into all the gears just fine so I'm not sure what might be going on. Here are some details in case it helps troubleshoot.
-Bike has 15,530 miles -Adjusted my valves to the recommended .10/.15 specs -Bled the clutch fluid to just above the viewing window (it was pretty nasty and brown) -No modifications have been made to the bike aside from me removing the airbox snorkel part to make a little more room under the seat. -I have not made any adjustments to the clutch lever pin/plunger since purchasing the bike but I did check it and everything is tight.
I'm hoping this isn't a major tear apart situation and thought that perhaps after changing the clutch fluid and adjusting the valves, the situation would be fixed but unfortunately that is not the case. I appreciate whatever help can be provided.
kiwi dave GRiSO Capo
Posts : 735 Join date : 2014-04-23 Age : 77
Subject: Re: Slow to get going Wed Oct 07, 2020 12:13 pm
Slipping clutch, perhaps? Unfortunately, a bit of a major if it is,
lcjohnny GRiSO Capo
Posts : 1470 Join date : 2016-01-25 Age : 69
Subject: loss of torque or oomph at low revs Wed Oct 07, 2020 2:52 pm
Are the revs rising but no speed increase - that would indicate clutch slip --- sorry
If not that, and it is just gutless at low revs then... 1) that is unusual.. engines usually lose BMEP at high revs due to fuel, spark or compression issues
There is no 2) So my first thoughts are synchronise the throttles and check that all of the plugs are gapped and clean but a thought from the car world - if you are losing compression slowly (head gasket or a tight valve) that is worse when there is time for the gas to dribble out and less of a problem at higher engine speeds - particularly inlet valve at low speeds
So as you last touched the valves - set them back sloppy and ride it .... then see if it is better ?
Last edited by lcjohnny on Wed Oct 07, 2020 3:19 pm; edited 1 time in total
Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: Slow to get going Wed Oct 07, 2020 2:58 pm
My first thought is it's running on one cylinder at lower RPM. That is a sign of buggered plug cap usually.
As for the 'No overrun'? Can you expand on that as I have no ide what you mean.
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lcjohnny GRiSO Capo
Posts : 1470 Join date : 2016-01-25 Age : 69
Subject: Re: Slow to get going Wed Oct 07, 2020 3:19 pm
Thanks Pete for correcting me - missed the blindingly obvious
put an IR thermometer (or a blob of spit) on the exhausts ans check both are firing at tick over
DangWangi GRiSO Capo
Posts : 114 Join date : 2015-12-01 Age : 49
Subject: Re: Slow to get going Wed Oct 07, 2020 4:47 pm
Pete Roper wrote:
My first thought is it's running on one cylinder at lower RPM. That is a sign of buggered plug cap usually.
As for the 'No overrun'? Can you expand on that as I have no ide what you mean.
These are my plugs and being a novice at this stuff I didn't think they looked all that bad when I adjusted the valves but perhaps I am mistaken? What's a good way to check if the plug cap(s) are good/bad? As for the over-run, what I am trying to describe is that if I'm riding along at some speed, and then down-shift, normally the RPMs would rise but this does not seem to be happening anymore...I can feel and hear the "clink" into the lower gear but the engine almost seems like it stays in gear. I wish I could explain it better and if I had a cam, I'd try to get a recording of it. I suppose I could start with the easier stuff and re-bleed the clutch fluid, change the plugs and test the plug caps. I did not see any oil leaks anywhere but I haven't pulled the starter cover off yet to get a real good look inside. [You must be registered and logged in to see this image.]
sideshowbob GRiSO Capo
Posts : 1108 Join date : 2017-08-06 Age : 70
Subject: Re: Slow to get going Wed Oct 07, 2020 6:23 pm
With snorkel removed, make sure nothing is blocking the inlet.
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DangWangi GRiSO Capo
Posts : 114 Join date : 2015-12-01 Age : 49
Subject: Re: Slow to get going Thu Oct 08, 2020 10:50 am
sideshowbob wrote:
With snorkel removed, make sure nothing is blocking the inlet.
Good point and thank you, but nothing is or was, under the seat that would block the air box.
JohnA GRiSO Capo
Posts : 765 Join date : 2015-01-13 Age : 67
Subject: Re: Slow to get going Thu Oct 08, 2020 11:39 am
I remember Pete/ Beetle or someone saying you could keep the lights off in your garage or place of storage and you could see the arcing coming off the plug wire potentially. Or you could wrap them both up good with electrical tape and see if your problem goes away.
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GuzziSteve Fra Cristoforo
Posts : 828 Join date : 2016-04-14
Subject: Re: Slow to get going Thu Oct 08, 2020 12:22 pm
You could always get out of Chi and go out to Richmond, IL to see Jim at Rose Farm. He has a new local at Mories Place.
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DangWangi GRiSO Capo
Posts : 114 Join date : 2015-12-01 Age : 49
Subject: Re: Slow to get going Thu Oct 08, 2020 12:40 pm
GuzziSteve wrote:
You could always get out of Chi and go out to Richmond, IL to see Jim at Rose Farm. He has a new local at Mories Place.
That's good to know!!! I may end up having to go that route if it's not a fix I'm capable of. Thank you!
lcjohnny GRiSO Capo
Posts : 1470 Join date : 2016-01-25 Age : 69
Subject: Re: Slow to get going Thu Oct 08, 2020 2:24 pm
Is it only firing on one?
DangWangi GRiSO Capo
Posts : 114 Join date : 2015-12-01 Age : 49
Subject: Re: Slow to get going Fri Oct 09, 2020 5:39 pm
Hi friends! Finally got around to starting up the bike in the dark. Unfortunately, I didn't see any arching from the plug caps on either cylinder. I'm guessing it would be pretty obvious if there was a problem right? Do the wise ones of this forum think it's worth bleeding the clucht fluid again? The problem hasn't changed from before a fluid change to after so I'm guessing a fluid change won't fix the issue. I'm bummed out.
Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: Slow to get going Fri Oct 09, 2020 6:15 pm
The problem I have is I don't understand your description of the problem.
If you are still using the original caps I'd swap them to SB05E or F on principle. The letter suffix denotes what centre electrode they fit.
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antmanbee Tanabuso
Posts : 79 Join date : 2018-04-08
Subject: Re: Slow to get going Fri Oct 09, 2020 6:16 pm
It seems to me that if you down shift and the RPM's don't rise then you have a clutch problem. The RPM's would still rise if it is only running on 1 cylinder on a down shift. Either your clutch is out of adjustment if you are lucky or it is worn and needs replacing. Bleeding wont help for a clutch that is slipping. Another possibility is oil on the plates.
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DangWangi GRiSO Capo
Posts : 114 Join date : 2015-12-01 Age : 49
Subject: Re: Slow to get going Sat Oct 10, 2020 6:29 am
antmanbee wrote:
It seems to me that if you down shift and the RPM's don't rise then you have a clutch problem. The RPM's would still rise if it is only running on 1 cylinder on a down shift. Either your clutch is out of adjustment if you are lucky or it is worn and needs replacing. Bleeding wont help for a clutch that is slipping. Another possibility is oil on the plates.
Even with my lack of mechanical experience my gut tells me it's a clutch issue Even though I've never touched the clutch plunger setting since owning the bike, is there any point in messing with it now? I'd hate to add insult to injury and make matters potentially worse by futzing around with it.
DangWangi GRiSO Capo
Posts : 114 Join date : 2015-12-01 Age : 49
Subject: Re: Slow to get going Sat Oct 10, 2020 6:34 am
Pete Roper wrote:
The problem I have is I don't understand your description of the problem.
If you are still using the original caps I'd swap them to SB05E or F on principle. The letter suffix denotes what centre electrode they fit.
Thanks Pete. I've never changed the caps since owning the bike and have never performed this operation but I recall reading about it somewhere in this forum so perhaps I'll go that route first before harassing Mr. Jim at the Farm if you feel there may be a chance in that fixing the issue. Is there any difference/benefit between the two types of caps or is it just a pattern of personal preference?
Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: Slow to get going Sat Oct 10, 2020 6:58 am
?? As I said, which type depends on which electrode fitting your plugs have.
Look, you can try adjusting the lever plunger. It can't do any harm and may just fix the problem if it is the clutch.
eeyore Grignapoco
Posts : 189 Join date : 2016-09-09
Subject: Re: Slow to get going Sat Oct 10, 2020 10:31 pm
Get some data. Revs v engine speed etc. Are the valves set correctly - are you losing compression as the engine warms? To check for the caps sparking, the plastic covers need to be removed so you can look down the plug tube.
DangWangi GRiSO Capo
Posts : 114 Join date : 2015-12-01 Age : 49
Subject: Re: Slow to get going Sun Oct 11, 2020 12:46 pm
So I borrowed a buddy's IR thermometer and both cylinders are nice and hot. Took it for a ride and there doesn't seem to be any loss of power once I'm up and going but what I did notice is that in first gear from a dead stop I can release the clutch entirely and without any throttle, it will start to roll forward. Don't bikes typically stall if you release the clutch without any throttle? Also...it idles exactly at 1000K for what it's worth.
Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: Slow to get going Sun Oct 11, 2020 1:10 pm
OK. So that says it's a clutch issue. I'd try adjusting the plunger first.
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eeyore Grignapoco
Posts : 189 Join date : 2016-09-09
Subject: Re: Slow to get going Mon Oct 12, 2020 2:55 am
Pete Roper wrote:
OK. So that says it's a clutch issue. I'd try adjusting the plunger first.
Don't shout! Genuine Question.
He releases the clutch in first and the bike moves forward without stalling. How does that make it a clutch issue?
OK, so he doesn't say how the clutch is released but if it was slipping like a torque convertor at 1000rpm it would be unrideable.
Idle speed @1000 rpm sounds a little low but a 1200cc twin will creep along in first without the need for any throttle - a useful feature in the UK's city traffic. Many of these things end up on their side because the engine refuses to stall in first.
Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: Slow to get going Mon Oct 12, 2020 3:37 am
If he can slowly release the clutch lever and the bike doesn't move the clutch obviously is broken somehow or the hydraulic system is remaining pressurised when the lever is released. To me that makes it a clutch issue.
This still doesn't explain how it ever gets moving at all unless it's able to start moving when everything is cold but when the sealed system heats up it pressurises and preloads the actuating system.
The problem of course remains that I got one am not able to fully understand the symptoms as described so I'm pretty much flailing about in the dark. Process of elimination says adjust the plunger though.
antmanbee Tanabuso
Posts : 79 Join date : 2018-04-08
Subject: Re: Slow to get going Mon Oct 12, 2020 3:38 am
DangWangi wrote:
? Also...it idles exactly at 1000K for what it's worth.
I think the idle sounds a little high. it should idle about 1.1K, not 1000K (1,000,000) RPM.
eeyore Grignapoco
Posts : 189 Join date : 2016-09-09
Subject: Re: Slow to get going Mon Oct 12, 2020 4:01 am
[quote="Pete Roper"]If he can slowly release the clutch lever and the bike doesn't move the clutch obviously is broken somehow or the hydraulic system is remaining pressurised when the lever is released. To me that makes it a clutch issue. - I am reading it that the bikes moves forward when the clutch lever is released.