Not striking up

[courior]

Spray some easy start down the intake.. If it runs on this for a few secs you know the timing is good etc. Then its a fuel issue.

Courior

[The Bird Man]

Tried that earlier today pal, no luck I'm afraid. Just mis-fiered again

[courior]

Have you done a compression test? You have fuel and a spark. The only other thing you need is compression.

[ScottieJ]

Sounds like the dizzy timing might be 180* out. I.e it's trying to fire on the exhaust stroke of each cylinder not the compression stroke as the cam spins once for every 2 revolutions of the crank.

Swap leads 1&4 and 2&3 and then try.

[The Bird Man]

Not done a compression test, but that has made me think. I took off the timing belt cover off the other day and cranked it while doing so I noticed that the belt what slipping off the cam and crank sprockets, this will explain the wear on the timing belt cover itself. It looks like this has done it before, so much so it's worn a hole in it, two actuallly !! So I can see the belt itself while the cover is on. Also I should mention when cranking the crank pully doesn't turn true, almost like it's warped/bent so I took it off, laid it flat on the bench, nothing wrong with that. I did what you said Scottie all I got was a loud bang and a poof of smoke out of the carb, time and time again. Hmmm..... I'm starting to reckon this engine isn't so good ?

[kiwizook]

the timing belt shouldn't be slipping at all. the "warped feeling" is probably the fact that one side of the turn has to build up compresion, so it just feels restricted part of the way around. if the timing belt is slipping, then this needs to be sorted with a new belt, tensioner, and make sure the crank and cam are in the right spot when put back on

[The Bird Man]

Hmmm.. That makes sense with the crank pully, cheers pal Regarding the timing belt I shall try tightening it before I make any purchases. Although it doesn't feel loose or seem to have any slack in it. With the belt doing this could this be the cause of the engine not firing ? Also how much psi should the compression reading be ?

[courior]

This is from the Samurai Haynes, but i guess all engines are roughly the same.

[ScottieJ]

Sounds like a good backfire timing was deffo wrong with the leads reversed then.

I think it would be worth double checking it's all timed up correctly as well as doing the compression test.

The belt can walk off the pulleys without the crank aux pulley as that holds the belt on.
However excessive thrust play in the cam or crank can also cause the belt to walk.

[The Bird Man]

A good back fire ? Didn't know there was such a thing So the leads are in the right position with it backfiring now ? I shall do a compression test and check the engine timing today Thanks for the info there Courior

Update: Did the compression test, 155 psi on all 4 cylinders, choke all the way out. 170- 185 with the throttle all the way back, which one is the correct method ? Obviously I couldn't let the engine run for a while and warm up though.