Suzuki GSX250 e 1981 starting woes/ compression

[Chris46]

Good evening all.

I have the said bike in the title and it's being a little rat bag.

It's been stood for years and I've carried out the following, cleaned all connectors in the loom, replaced a few, sorted out bodge jobs also, it looks spot on to the wiring diagram. I've tested the signal generator, getting 125ohms. I don't know how to test a tr ignitor. I've replaced the coils, caps plugs and leads oh and plugs as they went bad, checked the timing against rhe right hand cylinder. I've got massive sparks, I've stripped and cleaned the carbs, reset back to book settings. Fixed a dodgy float needle. Checked and checked again valve clearances against the book, valve timing is good also. It turns over, sparks but doesn't even ignite the carb aerosol I'm spraying into the engine, I've bypassed the ignition switch to disprove that. I've put fuel in the carbs and only once it ran for 30 seconds and stopped. Hasn't since, I've done a dry compression test and I get 60psi on one and 80 on the other, and wet I get 100 on one and 90 on the other, the book says a comp ratio of 10.5:1 not sure but could be 130psi.

So what do you think? Low compression - fuel - Ignition circuit, any help would be awesome

Chris is a small garage in Norfolk.

[rennie]

Hello and Welcome

I have no idea! but someone will be along shortly

[SlowBusa]

Compression sounds very low

Not sure what its supposed to be but I would have guessed at least 120?

[Mr Fro]

Compression sounds very low

Not sure what its supposed to be but I would have guessed at least 120?

 

Yeah, 100psi is lawnmower territory.

I would have thought it to still fire a bit though. Is it points ignition?

[Chris46]

No points, solid state stuff, with a rotor, pick ups, to a igniter (CDI) and onto coils and plugs.

[Bianco2564]

Welcome.

Could be piston rings gummed up in the pistons.

My Honda 125 had been stood for years also and wouldn't start.Took the barrels off and carefully freed off the rings.

Can you do a leakdown test on it?

That will tell you where the loss of sealing is.

[megawatt]

Take plugs out, spray wd40 with a tube onto cylinder liners, stroke engine one rev with a spanner, not starter motor, spray more wd40, leave for 24 hours. Repeat 3 times, then see if it will start. Allow to get warm, cool down, then recheck compression.

[TimR]

Take plugs out, spray wd40 with a tube onto cylinder liners, stroke engine one rev with a spanner, not starter motor, spray more wd40, leave for 24 hours. Repeat 3 times, then see if it will start. Allow to get warm, cool down, then recheck compression.

 

Or a small amount of diesel will do same

And by stroke im sure MW means turn the engine over BY HAND using a spanner on the crankshaft nut

Not sit there singing Soft Kitty to it whilst gently stroking it

[megawatt]

Thanks for the translation Tim.

[Chris46]

The engine has been apart, rings are free around the piston grooves, and gaps are offset.

[Chris46]

Stripped it down,  surprised only took and hour and a half. On inspection of the L/H cylinder it's glazed which is to be expected at 28000 miles, rings are free on the piston, this one gave me about 80psi, the R/H was the same,  glazed and the rings stuck solid in the piston, they were free before, oh well, this one was at 60psi. Both Pistons give a bore clearance of 0.20mm. Off to machine shop to see if the bores are round and square. Probably not.Surprisingly Suzuki still hold stock of 0.50 piston ring sets, standard rings. Will come back with prices and how it got on. Not many people ever come back with replies or fixes on forums. 

[megawatt]

Check the seal on the valves by pouring liquid into the ports.

[Chris46]

The valve stem oils have been replaced and valves lapped in.

Been to machine shop, the engineer has checked the bores, they are fine within tolerance and the Pistons haven't collapsed in, so it's a glaze bust and new rings. I was expecting worse, as small bikes tend to have a tough life. Charged £20 for deglaze, just sourcing rings now.

[Bianco2564]

Looks like genuine rings are available.

Just checked out CMNSL, which is Dutch I think.

Try ringing your local Suzuki dealer with the part number,you might be surprised

If not CMNSL will ship to the UK.

Not sure if this is your model but you can go back and choose the right one.

https://www.cmsnl.com/suzuki-gsx250e-1982-z-general-export-e01_model13609/partslist/FIG10.html#results

My 26 year old RGV is on the excellent vintage program with Suzuki,with a few exceptions I can get almost everything for it from my local dealer within a couple of days.

Even bought a brand new crankshaft from them last year.