Suzy DT140 lacking power/revs

[Eeyore]

Hi
I took my Suzuki DT140 on a high speed run today (first time out this year) from Chichester to Priory Bay IOW and it ran great on the way out but on the way back was struggling for power and I couldn't get full revs. Tickover is fine just no power under load and could barely get onto the plane. Revving it out of gear it also didn't want to rev to the max but seemed to go about 3/4 throttle and build gradually from there.

Where do I start looking for the problem??

Already checked plugs and all looked the same. Anyway, wasn't running lumpy (just gutless) so don't think I was down a cylinder...

[TRevor Lawson]

No expert on suzuki's , but i would start by checking fuel, low or contaminated. fuel filter, blocked or collapsed breather /vent for tank, collapsed fuel pipes. also battery and cut out switch connections.throttle cables and linkages.blocked air filter.

[Eeyore]

OK, good checklist, thanks.

Fuel was full and fresh yesterday and fuel lines were new last year so pretty sure they are OK. In any cae if it was bad fuel I guess we'd have had problems on the outbound 8 miles?

We grounded the prop in the sand (very slightly) at slow speed as we set off back so at first i assumed maybe I'd bent the prop but that's fine and the hub looks good too.

Could there still be a connection?

Already checked for lose wires in case I rattled something loose but all seems OK there...

[freespirit3]

Sounds to me like fuel shortage, check all the fuel filters, it maybe one of the filters has picked some dirt up on your way out, was the fuel primer still hard or had it gone soft

[Eeyore]

Didn't check the primer bulb or tinker en route as I was more interested in making it back to Chi harbour!

Will make some basic checks later this week but in the meantime I've ordered a new primer bulb (was meaning to do that anyway) as mine is pretty old and I've heard they can go bad...

The bulb never really goes hard when priming either so maybe due for a change.