OzVMX Forum

Marque Remarks => Honda => Topic started by: suzuki27 on November 20, 2011, 07:34:49 pm

Title: Overall barrel dimensions for CR125 74/75 models
Post by: suzuki27 on November 20, 2011, 07:34:49 pm

I have 2 barrels supposedly for 74/75 CR125. While both have the same bore, inlet and exhaust port dimensions ,one of the barrels has larger finning. Does anyone have an idea here?

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: elsie 125 on November 20, 2011, 07:57:52 pm

larger finning is more likely a 76-77 cylinder

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: suzuki27 on November 21, 2011, 05:00:37 pm

Thanks elsie.  I half suspected that. They look the same on the inside except for the larger finning.

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: jimg1au on November 21, 2011, 06:56:10 pm

i belive the 75 is different in the porting to the 74
cheers
jim

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: dkupf on November 21, 2011, 07:27:01 pm

The sleeve on the 76 is a lot thicker and won't go into 74/75 cases.Darcy

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: ba-02-xr on November 22, 2011, 10:24:07 am

The 75 has a boost port above the inlet port. 73-74 does not.

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: suzuki27 on November 22, 2011, 09:04:45 pm

Its looking very much like I bought a 76 engine in a 75 frame! The area where the engine number is supposed to be is blank. I thought it had a new left side engine case and replacements came un-stamped. It was advertised as a 75 model . Not happy.

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: suzuki27 on November 28, 2011, 06:35:32 pm

Anyone know if a MR175 or anything Honda really has 'KT' stamped in the barrel beneath the exhaust outlet. After a bit more searching I found that the base gasket is the same for the CR125's- I looked from 75-78.
The larger OD sleeve in the barrel I have sits correctly in the cases- good fit. The 74/75 barrel I have fits on etc, but the OD of the sleeve being smaller leaves a pretty large gap between the sleeve and cases.
With no engine number to go on, I'm starting to think it might be a MR175 engine with a sleeved down barrel .
I checked some numbers and see the main bearings are the same in the MR175 and the CR125.

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: elsie 125 on November 29, 2011, 09:25:57 pm

 you would most likely have 76, 77 78, cases, most likely your whole engine is 1976- 1978

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: suzuki27 on November 30, 2011, 06:37:43 pm

Hi elsie, the KT has me stumped.The 76 and 77 barrels haven't got KT stamped on them- I believe
So is the sleeve a lot thicker (OD) on the 76-78 CR125's?

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: Noel on November 30, 2011, 09:10:52 pm

Bill
I doin't think the KT stamp is relavent to model, more likely a batch or manufacture code
I'll measure the OD of the sleeve tomorrow
Noel

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: suzuki27 on December 01, 2011, 09:53:31 pm

Thanks Noel that would be good.

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: Noel on December 02, 2011, 05:44:15 pm

Hi Bill,
OD of sleeve where it enters the cases 76/77 is 72.90
Cheers
Noel

Title: Re: Overall barrel dimensions for CR125 74/75 models
Post by: suzuki27 on December 04, 2011, 05:37:52 pm

My one measures the same- 72.90 give or take.
The other CR barrel I have measures about 63.5 mm OD of the sleeve where it enters cases.
Interesting that the 74/75 case numbers supercede to the the later 76/7/8 numbers.
I believe all or most of the internals are the same.