T25, top speed 45 MPH

[zxr750]

Hello everyone,

joined the site to hopefully get some answers to a couple of mechanical issue I have & post some pics etc, of an ongoing restoration project.

First of it's a 1981 T25 2.0L petrol, that's been stood for 2 years, super Viking conversion.

Problem 1, clutch stiff & has to be pushed hard to the floor & still hard to engage gears, no crunching or clutch slip.

Problem 2, very slow on pick up & can only reach a whopping 45MPH, put fresh fuel in still the same

Van starts easy & ticks over like a watch.

Any advice will be appreciated.

Thanks in advance.

[Dad]

Is the throttle opening all the way?

[zxr750]

Yes it revs out in neutral, its very sluggish under load.

Hits 45 in 3rd put it in 4th & starts to slow again.

Also the build up to max speed is very slow.

Do think it could be related to the clutch problem?

Cheers.

[faggie]

whereabouts are you

[zxr750]

Leicestershire.

[California Dreamin]

Yes it revs out in neutral, its very sluggish under load.

Hits 45 in 3rd put it in 4th & starts to slow again.

Also the build up to max speed is very slow.

Do think it could be related to the clutch problem?

Cheers.

You didn't really answer the question of whether the throttle opens fully, as most will red line with half throttle applied in neutral but under load the engine probably wouldn't top 50mph.

All the usual checks:
1) Air filter blocked
2) Good even compression on all 4 cylinders (probably the first thing to do as it checks basic mechanical fitness)
3) Timing roughly correct at revs (there is usually a BTDC @ 2500rpm or similar)
4) Fuel filter blocked however you describe the running as smooth (fuel blockage would produce hesitation/jerking)
5) Massive air leak (however, the same applies...it wouldn't run as you describe)
5) Petrol gone off (which you say you have addressed).

Clutch heavy could be a badly worn pressure plate OR very dry release bearing sleeve/input shaft splines rusty/cable or release arm pivots rusty/dry/seizing.

Martin

[Dad]

Put a brick on the gas pedal, engine NOT on, is the carb open to the stop? Mine did 70+ but wasn't fully open.

[supergalaxy]

Could it be the brakes binding? Jack up each wheel in turn to check that they spin freely. Sorry if this sounds elementary but it is sometimes the simple things that can catch us out. Best of luck.

[kevtherev]

Timing Advance working?

[zxr750]

Thanks all,

the throttle wasn't opening fully adjusted cable to suit now have more power.

Still not 100%, hesitant when picking up drive & struggles up hills.

I have a manual coming in the next couple of days so will give it a service & set up.

I have a set of vacuum hoses for 2/3 & 4 cylinder motorcycles, could I use them for balancing the carbs?

Cheers.

[zxr750]

Went to change inline fuel filter & it has one on both sides,

Is there any need for one on the return?

[CovKid]

No.

[zxr750]

OK mate, thanks for the link.

Do you know of anyone using POR15 tank sealer to cure the rust problem?

[kevtherev]

A lot of faff when it's easier to fit a new un

[bigherb]

Went to change inline fuel filter & it has one on both sides,

Is there any need for one on the return?

2.0 ltr air cooled don't have a return fuel line but the 1.6 ltr does, sure it is a 2.0ltr and not a 1.6 ltr with twin carbs?