Sluggish take off

A whole section dedicated to the Suzuki Burgman
Stumpy 32
Posts: 19
Joined: Thu Oct 11, 2018 12:45 pm
Current Ride: Suzuki Burgman 400
Location: North Wiltshire, UK

Sluggish take off

Post by Stumpy 32 »

Evening all. I've replaced the belt and variator rollers on my recently bought K4 Burgman, smoother now on take off as some of the rollers were worn unevenly. But, (isn't there always a but?) the bike begins to move at about 1800rpm rather than the Suzuki recommended 2300-2900rpm. This makes the bike very sluggish on take off and it definitely struggles to pull away on hills. The Suzuki "lock up" test says this should happen at 3500-4500rpm, I seem to be getting nowhere near that speed.
The new rollers weigh 21 grammes (std. weight?), the old worn rollers weigh around 19 grammes each.
On the road, once moving the bike seems fine.
Prior to doing the work I could blip the throttle to over 2000rpm and the bike wouldn't move, can't do that now.
I'm thinking I've assembled something incorrectly, the variator?
Any ideas?
Thanks, John

User avatar
Ralph
Posts: 965
Joined: Fri Jun 01, 2012 7:20 am
Current Ride: Yamaha X-max 300 300
Location: Near Fleetwood

Re: Sluggish take off

Post by Ralph »

Did you do anything to the rear pulley/clutch it’s more likely the clutch than the veriator.
Ralph
Nr Fleetwood
Yamaha X-max 300
Ariel NG 350
AJS Model 18S.

icon_maxi_scoot.gif


Image

Image

Image

Stumpy 32
Posts: 19
Joined: Thu Oct 11, 2018 12:45 pm
Current Ride: Suzuki Burgman 400
Location: North Wiltshire, UK

Re: Sluggish take off

Post by Stumpy 32 »

I didn't dismantle the clutch but I used an airline to blow the dust out of it, not that there was much in there.
Iv'e now stripped the drive again, there is now a distinct "shiny" mark around the variator pulley sheaves, I think I could hear a squeal as if the belt was slipping, this could confirm that is happening. The marks are at about the midpoint on the sheaves. This might suggest that the variator is not working correctly, that is to say it is not dropping to a low enough "gear". hence the sluggish get away. Might also explain why the clutch locks up early?

User avatar
Ralph
Posts: 965
Joined: Fri Jun 01, 2012 7:20 am
Current Ride: Yamaha X-max 300 300
Location: Near Fleetwood

Re: Sluggish take off

Post by Ralph »

If as you say it is not dropping low enough then would be like setting off in to high a gear so you could be on the right track
Ralph
Nr Fleetwood
Yamaha X-max 300
Ariel NG 350
AJS Model 18S.

icon_maxi_scoot.gif


Image

Image

Image

Normsthename
Benefactor
Posts: 694
Joined: Wed Mar 25, 2009 5:04 pm
Current Ride: Royal Enfield Classic 350
Location: Leicester, UK

Re: Sluggish take off

Post by Normsthename »

Did you fit an original Suzuki Belt or an aftermarket one?
If the belt was a different width it would alter the gearing etc???

Andy
2024 Royal Enfield Classic 350
1975 Honda GL1000 Goldwing
2016 Microcar MGO3 - 4 wheeled Scooter with a roof :D

Stumpy 32
Posts: 19
Joined: Thu Oct 11, 2018 12:45 pm
Current Ride: Suzuki Burgman 400
Location: North Wiltshire, UK

Re: Sluggish take off

Post by Stumpy 32 »

The new belt is an after market item, slightly wider, ~1mm. I refitted the old belt, that is on the maximum width specified, made no difference. I am wondering if I have done something to the variator. I think that the rollers need to be positioned so the pulley sheaves are in the low gear position on assembly. They seem to find there own positions! Anyway of holding the variator in the low gear position for assembly? the Suzuki manual hints at this, careful assembly is required "so as not to allow the roller to dislocate" it says.

John

User avatar
Ralph
Posts: 965
Joined: Fri Jun 01, 2012 7:20 am
Current Ride: Yamaha X-max 300 300
Location: Near Fleetwood

Re: Sluggish take off

Post by Ralph »

It's a few years since I had a Burgman in bits but cant remember any thing to watch out for,
I fitted Doc Pulley weights on one and they could turn if you did not keep the bits pressed together
which was a bit finger trapping but the normal rollers just settle in the right place.
I used to turn the ventilator as I tightened the nut so the belt settled and never had any problems.
Ralph
Nr Fleetwood
Yamaha X-max 300
Ariel NG 350
AJS Model 18S.

icon_maxi_scoot.gif


Image

Image

Image

User avatar
roadster
Benefactor
Posts: 495
Joined: Tue Sep 13, 2016 2:06 pm
Current Ride: Silence S01

Re: Sluggish take off

Post by roadster »

Stumpy 32 wrote: Mon Oct 29, 2018 2:24 pm The new rollers weigh 21 grammes (std. weight?), the old worn rollers weigh around 19 grammes each.
The change in roller weight alone would be noticeably slower on acceleration, especially if the old ones were worn enough to close the pulley halves less hence giving a smaller effective pulley diameter both on acceleration and when at the top of their travel. When, on previous Piaggios, I used Dr. Pulleys I found they outlasted standard rollers and gave better performance using the reduced weight recommended.
Located on UK South Coast
SYM Joymax 125 and Honda CB300R. Previously Silence S01, Kymco AK550, Triumph Tiger 850, Triumph Street Twin etc...

SH125Paul
Benefactor
Posts: 1983
Joined: Fri May 28, 2010 7:03 am
Current Ride: SH125 - NC750X DCT
Location: SE London

Re: Sluggish take off

Post by SH125Paul »

After market belt may be a slightly different LENGTH as well a slightly different WIDTH...
My Recommendation would be OE Belt... and Dr Pulley Rollers / Sliders at OE weight... rather than dropping the 10%

I have fitted Dr Pulleys in my XMax 250, XMax 400, and SH125... and after going down the 10% (or slightly less) have re-ordered for OE weight...
The XMax 400 and SH125 was way to revvy for stop start commuting traffic... the drop of 10% may be more suitable for A road and M Way Cruising...

User avatar
Ralph
Posts: 965
Joined: Fri Jun 01, 2012 7:20 am
Current Ride: Yamaha X-max 300 300
Location: Near Fleetwood

Re: Sluggish take off

Post by Ralph »

I had a gates belt on my burger no problems but the 07 on model used a different more expensive belt just wounding if you have the right one . I also had doc pulley weights they were 21g but I found it a bit revvy so added a little weight they were just over 22g and seemed about right, still reved a bit higher below about 50 but lower when at speed.
Ralph
Nr Fleetwood
Yamaha X-max 300
Ariel NG 350
AJS Model 18S.

icon_maxi_scoot.gif


Image

Image

Image

Post Reply