Author Topic: RM400 creeping clutch  (Read 205 times)

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Offline Curtis

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RM400 creeping clutch
« on: January 14, 2019, 12:50:08 PM »
I have a 1978 RM400 in good condition, everthing original and adjusted correctly.
When the bike is cold its not too bad but once the bikes warms up the clutch still wants to slightly pull with the lever all he way in.
Was this a common issue on these back in the day? Any ideas on a fix? I was going to try a clutch lever and perch with a longer throw.

Offline John Orchard

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Re: RM400 creeping clutch
« Reply #1 on: January 14, 2019, 01:01:45 PM »
l'm having the same issue with my CR500, l've tried thinner oil, different lever ratios, my next check is to see if l have any warped plates.
Johnny O - Tahition_Red factory rider.

Offline GMC

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Re: RM400 creeping clutch
« Reply #2 on: January 14, 2019, 01:07:24 PM »
Warped plates or grooves in the basket that are keeping the plates in the closed position.

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Offline bazza

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Re: RM400 creeping clutch
« Reply #3 on: January 14, 2019, 02:57:21 PM »
What GMC said, or your oil? Try ATF
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Offline Momus

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Re: RM400 creeping clutch
« Reply #4 on: January 14, 2019, 04:19:33 PM »
If it's a 400C with the RH side mechanism the problem is the magnesium clutch cover oil canning and not pulling the pressure plate clear.
Battled this on my 370. Get a daisy wheel clutch lever set up and over adjust at the line and wind off when under way.

Offline Hoony

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Re: RM400 creeping clutch
« Reply #5 on: January 14, 2019, 07:27:14 PM »
sounds like grooved baskets.....not allowing the plates to fully release.
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Offline John Orchard

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Re: RM400 creeping clutch
« Reply #6 on: January 14, 2019, 09:14:40 PM »
sounds like grooved baskets.....not allowing the plates to fully release.


The basket on my CR looks like new?
Johnny O - Tahition_Red factory rider.

Offline Oldfart

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Re: RM400 creeping clutch
« Reply #7 on: January 14, 2019, 10:06:50 PM »
File the finger grooves out and drill some holes in you top hat

Offline TT5 Matt

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Re: RM400 creeping clutch
« Reply #8 on: January 15, 2019, 01:51:03 AM »
has the sleve on the input shaft the clutch basket spins on been crushed by overtightening the nut?needle bearing that runs on the sleve ok?both will give creeping along with badly galled clutch basket fingersi. remember an  dr650 that you couldn't tighten the clutch hub nut to specs coz no clearance on the sleve/trust washers so just tighten till it started to grab and back off till it was free and use the lock tab to stop the nut from undoing.found a lot of suzukis like that

Offline John Orchard

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Re: RM400 creeping clutch
« Reply #9 on: January 15, 2019, 08:38:08 AM »
has the sleve on the input shaft the clutch basket spins on been crushed by overtightening the nut?needle bearing that runs on the sleve ok?both will give creeping along with badly galled clutch basket fingersi. remember an  dr650 that you couldn't tighten the clutch hub nut to specs coz no clearance on the sleve/trust washers so just tighten till it started to grab and back off till it was free and use the lock tab to stop the nut from undoing.found a lot of suzukis like that


Good point Matt ! l will check that :-)
Johnny O - Tahition_Red factory rider.

Offline Curtis

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Re: RM400 creeping clutch
« Reply #10 on: January 15, 2019, 09:36:27 AM »
All good points thanks guys, (clutch basket in good condition, minimal grooving) ill have a play and report back.