2.25 petrol 5 bearings blowing!

[CDNRover]

Hi,
I'm having some problems with a 2.25 petrol engine. The carburettor is new (webber 34). I try to set it but wasn't able to have the engine running without the choke. Even at running temp. it need the choke. I have set the idle screw to full to have it running approx. 800rpm. I have done a static timing. The engine is having difficulty pulling is own weight on a flat land. I've try on low 1st and I have to get it to full rev and play with the clutch to get it moving.
Also there is a strong blowing at the exhaust. It's so strong that I can't put my hand there... Maybe something is wrong with the timing after all? Maybe the valve timing is out? So out that maybe part of the explosion is going straight to the exhaust?

Can anyone help? I'm doing it for a friend and it's really frustrating..

[BellaCoola]

Hi Cdn Rover,

I also have a 5mb 2.25 and have recently gone through three (3) new Weber 34ICH carbs. All the carbs we received were "bad". The fuel mixture could not be adjusted and sat around 8 or 9ppm. It should be around 1.5 (give or take). It seems that there is a bad batch of Webers being shipped that just don't work. I ended up having my old Weber rebuilt, and also added the solenoid shut-off switch that solved my run-on as well.

The only way you are going to know is if you have a tailpipe reader to determine your mixture rate.

BTW...I run my timing (with Petronix Electronic Ignition) at +6 TDC.

Good luck.

[CDNRover]

How can I figure out if the carburettor isn't good? I mean I have a couple of theories of reasons why it doesn't run well.. Is there a way to make sure the carb is faulty?

[Tim Smith]

I'd check and recheck that the carburetor and intake system is bolted down tight. I'd also make sure all of the vacuum holes have been given a home or have been closed off and aren't leaking.

Not sure about the exhaust but maybe the gasket between the intake and exhaust manifold is failing? You are talking about under the hood blowing, right?